- All instructions over serial: are terminated with three bytes of 0xFF 0xFF 0xFF
ie: decimal:255
or hex:0xFF
or ansichar:ÿ
or binary:11111111
byte ndt[3] = {255,255,255}; write(ndt,3); // or print("\xFF\xFF\xFF"); // or print("ÿÿÿ")
- All instructions and parameters are in ASCII
- All instructions are in lowercase letters
- Blocks of code and enclosed within braces { } can not be sent over serial this means if, for, and while instructions can not be used over serial
- A space char 0x20 is used to separate instructions from parameters.
- There are no spaces in parameters unless specifically stated
- Nextion uses integer math and does not have real or floating support.
- Assignment are non-complex evaluating fully when reaching value after operator.
- Comparison evaluation is non-complex. Use nesting when and as required.
- Instructions over serial are processed on receiving termination (see 1.1)
- Character escaping is limited to 0x0D by using two text chars \r
- Nextion does not support order of operations.
sys0=3+(8*4)// is invalid.
- 16-bit 565 Colors are in decimal from 0 to 65535 (see 5.Note)
- Text values must be encapsulated with double quotes: ie “Hello”
- Items within specific to Enhanced Models are noted with *K*
- Transparent Data Mode (used by addt and wept commands)
MCU sending to Nextion- MCU sends instruction. ie: wept 30,20ÿÿÿ or addt 1,0,320ÿÿÿ
- Nextion requires ~5ms to prepare for transparent mode data transfer
- Nextion sends Ready 0xFE 0xFF 0xFF 0xFF Return Data (see 7.30)
- MCU can now send specified quantity (20) of raw bytes to Nextion
- Nextion receives raw bytes from MCU until specified quantity (20) is received
- Nextion sends Finished 0xFD 0xFF 0xFF 0xFF Return Data (see 7.29)
- MCU and Nextion can proceed to next command
Note: Nextion will remain waiting at step 5 until every byte of specified quantity is received.
– During this time Nextion can not execute any other commands, and may indeed hang if the MCU fails to deliver the number of bytes as specified by the command parameter.
– data quantity limited by serial buffer (all commands+terminations + data < 1024) - Only component attributes in green and non readonly system variables can be assigned new values at runtime. All others are readonly at runtime with the exception of .objname
- Numeric values can now be entered with byte-aligned hex. ie: n0.val=0x01FF
- Advanced. Address mode is an advanced technique prepending the serial instruction with two bytes for the address. Two byte address is to be sent in little endian order, ie: 2556 is sent 0xFC 0x09. By default, the Nextion address is 0 and does not require two byte prefixing. When the two byte addressing is used, Nextion will only respond to the command if its address matches the two byte prefix, or the transmitted address is 65535 broadcast. See the addr system variable.
- Advanced. Protocol Reparse mode is an advanced technique that allows users to define their own incoming protocol and incoming serial data handling. When in active Protocol Reparse mode, incoming serial data will not be processed natively by the Nextion firmware but will wait in the serial buffer for processing. To exit active Protocol Reparse mode, recmod must be set back to passive (ie: in Nextion logic as recmod=0), which can not be achieved via serial. Send DRAKJHSUYDGBNCJHGJKSHBDNÿÿÿ via serial to exit active mode serially. Most HMI applications will not require Protocol Reparse mode and should be skipped if not fully understood.
- Commenting user code inside Events uses the double-slash (two characters of forward slash // ) technique. See 2.27 for proper usage.
2. Assignment Statements
- Text =
Assignment. Right side will be evaluated with result placed in left side. Component .txt-maxl needs to be large enough to hold result.t0.txt="Hello"
- Text +=
Text Addition. Will concatenate left side with right side with result placed left side.
ie t0.txt+=”Hello” is equivalent to t0.txt=t0.txt+”Hello”.
t0.txt=”-“+t0.txt becomes t0.txt=t0.txt+”-“. Use temp variable to prepend.va0.txt=t0.txt t0.txt="-"+va0.txt t0.txt+=" World"// append " World" to t0.txt //When contents of t0.txt is "Hello" becomes "Hello World"
- Text -=
Text Subtraction. Will remove right side (a specified numeric amount of characters to remove) from end of left side and result placed in left side.t0.txt-=4 t0.txt=t0.txt-4// remove last 4 chars from t0.txt
- Text \
Escape Character.
Supported is \r hex 0x0D. (see 1.11)t0.txt="\r"
- Text ==
Boolean Equality. Evaluate left side to right side.
If both left and right sides are the same creates a true conditionif(t0.txt==va0.txt) { }
- Text !=
Boolean Inequality. Evaluate left side to right side.
If both left and right sides are different creates a true conditionif(t0.txt!=va0.txt) { }
- Numeric =
Assignment. Right side of equation will be evaluated and result placed in left side. If more than one operator on right side, full evaluation and assignment will occur at each operator.n0.val=bauds// places bauds value in n0.val component
- Numeric +=
Numeric Addition. Adds value of left side and right side with result placed in left side. n0.val+=4 is equivalent to n0.val=n0.val+4n0.val+=va0.val
- Numeric -=
Numeric Subtraction. Subtracts right side from left side with result placed in left side. n0.val-=4 is equivalent to n0.val=n0.val-4n0.val-=60// decreases value of n0.val by 60
- Numeric *=
Numeric Multiplication. Multiplies left side with right side with product result placed in left side. n0.val*=2 is equivalent of n0.val=n0.val*2n0.val*=2
- Numeric /=
Numeric Division. Equates division of numerator (left side) and divisor (right side) and places integer quotient in left side. 60000/20001=2n0.val/=60
- Numeric %=
Numeric Modulo. Equates division of numerator (left side) and divisor (right side) and places integer remainder in left side. 60000/20001=19998n0.val%=60
- Numeric <<
Arithmetic Bit Shift Left. Moves all bits specified number to the left.
Using the 16-bit example that follows, (32-bit uses similar rules)
All bits shifted above 15 are lost and undefined bits become 0
n0.val=n0.val<<4 0 0 0 0.0 0 1 1.1 1 0 0.0 0 0 1 0 0 1 1.1 1 0 0.0 0 0 1. 0 0 1 1.1 1 0 0.0 0 0 1.0 0 0 0
- Numeric >>
Arithmetic Bit Shift Right. Moves all bits specified number to the right.
Using the 16-bit example that follows, (32-bit uses similar rules)
All bits shifted below 0 are lost and undefined bits become the signed bit.
When signed bit is 1 (value is negative) then left filled is with 1’s
When signed bit is 0 (value is positive) then left filled is with 0’sn0.val=n0.val>>4 0 0 0 0.0 0 1 1.1 1 0 0.0 0 0 1 0 0 0 0.0 0 1 1.1 1 0 0 0 0 0 0.0 0 0 0.0 0 1 1.1 1 0 0
- Numeric &
Logical Bitwise AND. Compares all bits left side to all bits right side(mask)
Using the 16-bit example that follows, (32-bit uses similar rules)
Result is a bit of 1 where both left and right bits were 1n0.val=n0.val&35381 0 1 0 1.1 0 1 1.0 0 1 0.0 1 0 1 n0.val of 23333 1 0 0 0.1 0 1 0.0 0 1 1.0 1 0 1 mask of 35381 0 0 0 0.1 0 1 0.0 0 1 0.0 1 0 1 result is 2597
- Numeric |
Logical Bitwise OR. Compares all bits left side to all bits right side
Using the 16-bit example that follows, (32-bit uses similar rules)
Result is a bit of 1 where either left or right bits were 1n0.val=n0.val|35381 0 1 0 1.1 0 1 1.0 0 1 0.0 1 0 1 n0.val of 65519 1 0 0 0.1 0 1 0.0 0 1 1.0 1 0 1 constant 35381 1 1 0 1.1 0 1 1.0 0 1 1.0 1 0 1 result is 56117
- Numeric ==
Boolean Equality. Evaluate left side to right side.
If both left and right sides are the same creates a true conditionif(n0.val==va0.val) { }
- Numeric !=
Boolean Inequality. Evaluate left side to right side.
If both left and right sides are different creates a true conditionif(n0.val!=va0.val) { }
- Numeric < .
Boolean Less than. Evaluate left side to right side.
If left side is less than right side creates a true condition
//note in the example below there should be no space after <.
while(n0.val< va0.val) { }
- Numeric <=
Boolean Less than or Equal. Evaluate left side to right side.
If left side is less than or equal to right side creates a true condition
while(n0.val<=va0.val) { }
- Numeric >
Boolean Greater than. Evaluate left side to right side.
If left side is greater than right side creates a true conditionwhile(n0.val>va0.val) { }
- Numeric >=
Boolean Greater than or Equal. Evaluate left side to right side.
If left side is greater than or equal to right side creates a true conditionwhile(n0.val>=va0.val) { }
- Code { }
Code Block begins with open brace { on line by itself
Code Block ends with closing brace } beginning a new line
see if (see 3.25) while (see 3.26) and for (see 3.27) - Code ( )
Condition enclosure begins with open parenthesis (
and ends with closing parenthesis ) at end of line
see if (see 3.25) while (see 3.26) and for (see 3.27) - Code .
Period Separator. Separates Page, Component and Attributes
Also used with page index and component array. (see 2.26)page1.va0.val// or p0.pic
- Code [ ]
Array[index]. There are 3 arrays. Keyboard source showcases 2 arrays.
The b[.id] component array which takes component .id as index
The p[index] page array which takes page index as index
These (p[].b[]) need to be used with caution and mindful purpose. Reference to a component without specified Attribute can create for long and potentially frustrating debug sessions. The third array is the Serial Buffer Data u[index] array. This is valid when in active Protocol Reparse mode. Protocol Reparse is an advanced technique that should be skipped if not fully understood.p[pageindex].b[component.id].attribute// global scope b[component.id].attribute// local scope on current page
- Comment //
Double-Slash Commenting to add user comments to code.
Everything to the right of, and including, the double-slash is a comment that will not be executed by the Nextion interpreter. Comments should: 1) occur on a line by themselves with the double-slash at the beginning of the line (no leading spaces), 2) immediately following code on a line without a space separating code and the double slash. Commenting of code blocks should occur: 1) before the condition/iteration 2) inside the opening and closing braces 3) after the code block. Notes: It is important to note that comments can not interrupt code blocks without causing an “Error: Index was outside the bounds of the array”. Comments are counted towards the overall “code + attributes” hard limit of 65534// these are valid comments sys0=0// reset sys0 to zero
The following showcases valid/invalid use
//valid comment before condition/iteration for(sys0=0;sys0<=sys1;sys0++) // invalid comment between condition/iteration and block { doevents//valid comment after code on same line // valid comment inside block } // valid comment outside block
3. Operational Instructions
- page
Parameter Count 1
Change page to page specified. Unloads old page to load specified page.
Nextion loads page 0 by default on power on. (see also wup 6.16)
usage: page pid
pid is either the page index number, or pagenamepage 0// Change page to indexed page 0 page main// Change page to the page named main
- ref
Parameter Count 1
Refresh component (auto-refresh when attribute changes since v0.38)
– if component is obstructed (stacking), ref brings component to top.
usage: ref cid
cid is component’s .id or .objname attribute of component to refresh
– when is 0 (page component) refreshes all on the current page.ref t0// Refreshes the component with .objname of t0 ref 3// Refreshes the component with .id of 3 ref 0// Refreshes all components on the current page (same as ref 255)
- click
Parameter Count 2
Trigger the specified components Touch Press/Release Event
As event code is always local, object can not be page prefixed
usage: click cid,event
cid is component’s .id or .objname attribute of component to refresh
event is 1 to trigger Press Event, 0 to trigger Release Events.click b0,1// Trigger Touch Press Event of component with .objname b0 click 4,0// Trigger Touch Release Event of component with .id 4
- ref_stop
Parameter Count 0
Stops default waveform refreshing (will not refresh when data point added)
– waveform refreshing will resume with ref_star (see 3.5)
usage: ref_stopref_stop// stop refreshing the waveform on each data point added
- ref_star
Parameter Count 0
Resume default waveform refreshing (refresh on data point add)
– used to resume waveform refreshing stopped by ref_stop (see 3.4)
usage: ref_startref_star// resume default refreshing, refresh on each data point added
- get
Parameter Count 1
Send attribute/constant over serial (0x70/0x71 Return Data)
usage: get attrib
attrib is either numeric value, .txt contents, or constant
– attrib can be a global scope attribute when page prefixed.get t0.txt// sends text contents of t0.txt in 0x70 Return Data format get "123"// sends text constant "123" in 0x70 Return Data format get n0.val// sends numeric value of n0.val in 0x71 Return Data format get 123// sends numeric constant 123 in 0x71 Return Data format get page0.va0.val// sends page0's va0.val in 0x71 Return Data format
- sendme
Parameter Count 0
– number of currently loaded page is stored in system variable dp
– used in a page’s initialize event will auto-send as page loads
usage: sendme
is component’s .id or .objname attribute of component to refreshsendme// sends the value of dp in 0x66 Return Data Format
- cov
Parameter Count 3
Convert variable from numeric type to text, or text to numeric type
– text must be text ASCII representation of an integer value.
– source and destination types must not be of the same type
– when length is fixed and value is less, leading zeros will be added
ie: src numeric value of 123 with length 4, result is dest text “0123”
– dest txt_maxl and length needs be large enough to accommodate conversion.
ie: src numeric value of 123 with length 0, result is dest text “123”
– when value is larger than length, .txt results in a truncation
– it is recommended to handle source length in user code before cov
Note: v0.53 changed behaviour from previous pre v0.53 behaviours.
cov is deemed undefined if source is larger than length or the dest txt_maxl is
smaller than the requested length. Some undefines are exploitable.
usage: cov src,dest,length
src is text attribute (or numeric attribute when is text)
dest is numeric attribute (or text attribute when is numeric)
length will determine if leading zeros added to conversion to textcov h0.val,t0.txt,0// convert value of h0 into t0.txt without leading zeros cov t0.txt,h0.val,0// convert integer into t0.txt from h0.val ignored. cov h0.val,t0.txt,4// convert value of h0 into t0.txt with exactly 4 digits Invalid: cov h0.val,va0.val,0// Invalid: cov t0.txt,va0.txt,0// src & dest same type.
covx
Parameter Count 4
Convert variable from numeric type to text, or text to numeric type
– text must be text ASCII representation of an integer value.
– source and destination types must not be of the same type
– when source is numeric, hex format and length not 0 and <4.
ie: (len 2) positive significant (byte 0 to 3), 123 = 0000007B = 007B
ie: (len 2) negative significant (byte 3 to 0), -123 = FFFFFF85 = FF85
– value is more than allowed space results in a truncation
– it is recommended to ensure handling source length in user code before covx
– in v0.53, covx is deemed undefined if source is larger than length or
dest txt_maxl is smaller than requested length.
(some of these undefines, can be exploited)
ie: src numeric value of 123 with length 0, result is dest text “123”
– when length is fixed and value is less, leading zeros will be added
ie: src numeric value of 123 with length 4, result is dest text “0123”
– when value is larger than length, .txt truncated to least significant digits
ie: src numeric value of 23425 with length 4 result is dest text “3425”
usage: covx src,dest,length,formatsrc is text attribute (or numeric attribute when is text)
dest is numeric attribute (or text attribute when is numeric)
length will determine if leading zeros added to conversion to text
format 0: integer, 1: Comma separated 1,000s, 2: Hexcovx h0.val,t0.txt,0,0 // convert value of h0 into t0.txt without leading zeros covx t0.txt,h0.val,0,0 // convert t0.txt into integer in h0.val ignored. covx h0.val,t0.txt,4,0 // convert value of h0 into t0.txt with exactly 4 digits covx h0.val,t0.txt,4,1 // convert value of h0 into t0.txt with commas covx h0.val,t0.txt,4,2 // convert value of h0 into t0.txt in 2 bytes of hex digits Invalid: cov h0.val,va0.val,0// src & dest same type Invalid: cov t0.txt,va0.txt,0// src & dest same type.
- touch_j
Parameter Count 0
Recalibrate the Nextion device’s touch sensor
– presents 4 points on screen for user to touch, saves, and then reboots.
– typically not required as device is calibrated at factory
– sensor can be effected by changes of conditions in environment
usage: touch_jtouch_j // trigger the recalibration of touch sensor
- substr
Parameter Count 4
Extract character or characters from contents of a Text attribute
usage: substr src,dest,start,count
src is text attribute where text will be extracted from
dest is text attribute to where extracted text will be placed
start is start position for extraction (0 is first char, 1 second)
count is the number of characters to extractsubstr va0.txt,t0.txt,0,5// extract first 5 chars from va0.txt, put into t0.txt
- vis
Parameter Count 2
Hide or Show component on current page
– show will refresh component and bring it to the forefront layer
– hide will remove component visually, touch events will be disabled
– use layering with mindful purpose, can cause ripping and flickering.
– use with caution and mindful purpose, may lead to difficult debug session
usage: vis comp,state
comp is either .objname or .id of component on current page,
– valid .id is 0 – page, 1 to 250 if component exists, and 255 for all
state is either 0 to hide, or 1 to show.vis b0,0// hide component with .objname b0 vis b0,1// show component with .objname b0, refresh on front layer vis 1,0// hide component with .id 1 vis 1,1// show component with .id 1, refresh on front layer vis 255,0// hides all components on the current page
- tsw
Parameter Count 2
Enable or disable touch events for component on current page
– by default, all components are enabled unless disabled by tsw
– use with caution and mindful purpose, may lead to difficult debug session
usage: tsw comp,state
comp is either .objname or .id of component on current page,
– valid .id is 0 – page, 1 to 250 if component exists, and 255 for all
state is either 0 to disable, or 1 to enable.tsw b0,0// disable Touch Press/Release events for component b0 tsw b0,1// enable Touch Press/Release events for component b0 tsw 1,0// disable Touch Press/Release events for component with id 1 tsw 1,1// enable Touch Press/Release events for component with id 1 tsw 255,0// disable all Touch Press/Release events on current page
- com_stop
Parameter Count 0
Stop execution of instructions received from Serial
– Serial will continue to receive and store in buffer.
– execution of instructions from Serial will resume with com_star (see 3.14)
– using com_stop and com_star may cause a buffer overflow condition.
– Refer to device datasheet for buffer size and command queue size
usage: com_stopcom_stop // stops execution of instructions from Serial
- com_star
Parameter Count 0
Resume execution of instructions received from Serial
– used to resume an execution stop caused by com_stop (see 3.13)
– when com_star received, all instructions in buffer will be executed
– using com_stop and com_star may cause a buffer overflow condition.
– Refer to device datasheet for buffer size and command queue size
usage: com_starcom_star// resume execution of instruction from Serial
- randset
Parameter Count 2
Set the Random Generator Range for use with rand (see 6.14)
– range will persist until changed or Nextion rebooted
– set range to desired range before using rand
– power on default range is -2147483648 to 2147483647, runtime range is user definable.
usage: randset min,max
min is value is -2147483648 to 2147483647
max is value greater than min and less than 2147483647randset 1,100//set current random generator range from 1 to 100 randset 0,65535//set current random generator range from 0 to 65535
- code_c
Parameter Count 0
Clear the commands/data queued in command buffer without execution
usage: code_ccode_c// Clears the command buffer without execution
- print
Parameter Count 1
Send raw formatted data over Serial to MCU
– print/printh does not use Nextion Return Data, user must handle MCU side
– qty of data may be limited by serial buffer (all data < 1024)
– numeric value sent in 4 byte 32-bit little endian order
value = byte1+byte2*256+byte3*65536+byte4*16777216
– text content sent is sent 1 ASCII byte per character, without null byte.
usage: randset attr
attr is either component attribute, variable or Constantprint t0.txt// return 1 byte per char of t0.txt without null byte ending. print j0.val// return 4 bytes for j0.val in little endian order print "123"// return 3 bytes for text “123” 0x31 0x32 0x33 print 123// return 4 bytes for value 123 0x7B 0x00 0x00 0x00
prints
Parameter Count 2
Send raw formatted data over Serial to MCU
– prints does not use Nextion Return Data, user must handle MCU side
– qty of data may be limited by serial buffer (all data < 1024)
– numeric value sent in 4 byte 32-bit little endian order
value = byte1+byte2*256+byte3*65536+byte4*16777216
– text content sent is sent 1 ASCII byte per character, without null byte.
usage: usage: prints attr,length
attr is either component attribute, variable or Constant
length is either 0 (all) or number to limit the bytes to send.prints t0.txt,0// return 1 byte per char of t0.txt without null byte ending. prints t0.txt,4// returns first 4 bytes, 1 byte per char of t0.txt without null byte ending. prints j0.val,0// return 4 bytes for j0.val in little endian order prints j0.val,1// returns 1 byte of j0.val in little endian order prints "123",2// return 2 bytes for text “12” 0x31 0x32 prints 123,2// returns 2 bytes for value 123 0x7B 0x00
- printh
Parameter Count 1 to many
Send raw byte or multiple raw bytes over Serial to MCU
– printh is one of the few commands that parameter uses space char 0x20
– when more than one byte is being sent a space separates each byte
– byte is represented by 2 of (ASCII char of hexadecimal value per nibble)
– qty may be limited by serial buffer (all data < 1024)
– print/printh does not use Nextion Return Data, user must handle MCU side
usage: printh hexhex[space hexhex][…space hexhex]hexhex is hexadecimal value of each nibble. 0x34 as 34
space is a space char 0x20, used to separate each pairprinth 0D// send single byte: value 13 hex: 0x0D printh 0D 0A// send two bytes: value 13,10 hex: 0x0D0x0A
- add
Parameter Count 3
Add single value to Waveform Channel
– waveform channel data range is min 0, max 255
– 1 pixel column is used per data value added
– y placement is if value < s0.h then s0.y+s0.h-value, otherwise s0.y
usage: add waveform,channel,value
is the .id of the waveform component
is the channel the data will be added to
is ASCII text of data value, or numeric value
– valid: va0.val or sys0 or j0.val or 10add 1,0,30 // add value 30 to Channel 0 of Waveform with .id 1 add 2,1,h0.val // add h0.val to Channel 1 of Waveform with .id 2
- addt
Parameter Count 3
Add specified number of bytes to Waveform Channel over Serial from MCU
– waveform channel data range is min 0, max 255
– 1 pixel column is used per data value added.
– addt uses Transparent Data Mode (see 1.16)
– waveform will not refresh until Transparent Data Mode completes.
– qty limited by serial buffer (all commands+terminations + data < 1024)
– also refer to add command (see 3.19)
usage: add waveform,channel,qty
waveform is the .id of the waveform component
channel is the channel the data will be added to
qty is the number of byte values to add toaddt 2,0,20// adds 20 bytes to Channel 0 Waveform with .id 2 from serial // byte of data is not ASCII text of byte value, but raw byte of data.
- cle
Parameter Count 2
Clear waveform channel data
usage: cle waveform,channel
waveform> is the .id of the waveform component
channel is the channel to clear
- channel must be a valid channel: < waveform.ch or 255
- 0 if .ch 1, 1 if .ch 2, 2 if .ch 3, 3 if .ch=4 and 255 (all channels)cle 1,0// clear channel 0 data from waveform with .id 1 cle 2,255// clear all channels from waveform with .id 2
- rest
Parameter Count 0
Resets the Nextion Device
usage: restrest// immediate reset of Nextion device – reboot.
- doevents
Parameter Count 0
Force immediate screen refresh and receive serial bytes to buffer
– useful inside exclusive code block for visual refresh (see 3.26 and 3.27)
usage: doeventsdoevents// allows refresh and serial to receive during code block
- strlen
Parameter Count 2
Computes the length of string in param txt and puts value in param len
usage: strlen txt,len
txt must be a string attribute ie: t0.txt, va0.txt
len must be numeric ie: n0.val, sys0, va0.valstrlen t0.txt,n0.val// assigns n0.val with length of t0.txt content
btlen
Parameter Count 2
Computes the number of bytes in string for param txt and puts value in param len
usage: strlen txt,len
txt must be a string attribute ie: t0.txt, va0.txt
len must be numeric ie: n0.val, sys0, va0.valbtlen t0.txt,n0.val// assigns n0.val with length of t0.txt content
- if
Block
Conditionally execute code block if boolean condition is met
– execute commands within block { } if (condition) is met.
– nested conditions () is not allowed. invalid: ((h0.val+3)>0)
– block opening brace { must be on line by itself
– no space between block close brace } and else. valid: }else invalid: } else
– Text comparison supports ==, !=
– Numerical comparison supports >, <, ==, !=, >=, <=
– nested “if” and “else if” supported.
usage: if condition block [else if condition block] [else block]– (condition) is a simple non-complex boolean comparison evaluation
valid: (j0.val>75) invalid: (j0.val+1>75) invalid: (j0.val>now.val+60)if(t0.txt=="123456") { page 1 } if(n0.val==123) { b0.txt="stop" }else { b0.txt="start" } if(rtc==1) { t0.txt="Jan" }else if(rtc1==2) { t0.txt="Feb" }else if(rtc1==3) { t0.txt="Mar" }else { t0.txt="etc" }
- while
Block
Continually executes code block until boolean condition is no longer met
– tests boolean condition and execute commands within block { } if condition was met and continues to re-execute block until condition is not met.
– nested conditions () is not allowed. invalid: ((h0.val+3)>0)
– block opening brace { must be on line by itself
– Text comparison supports ==, !=
– Numerical comparison supports >, <, ==, !=, >=, <=
– block runs exclusively until completion unless doevents used (see 3.23)
usage: while condition block
– (condition) is a simple non-complex boolean comparison evaluation
valid: (j0.val>75) invalid: (j0.val+1>75)// decrement n0.val as lon as n0.val > 100. result: b0.val=100 // will not visually see n0.val decrement, refresh when while-loop completes while(n0.val>100) { n0.val-- } //decrement n0.val as long as n0.val > 100. result: n0.val=100 // will visually see n0.val decrement, refresh each evaluation of while-loop while(n0.val>100) { n0.val-- doevents }
- for
Block
Iterate execution of code block as long as boolean condition is met
– executes init_assignment, then tests boolean condition and executes
commands within block { } if boolean condition is met, when iteration of
block execution completes step_assignment is executed. Continues to
iterate block and step_assignment until boolean condition is not met.
– nested conditions () is not allowed. invalid: ((h0.val+3)>0)
– block opening brace { must be on line by itself
– Text comparison supports ==, !=
– Numerical comparison supports >, <, ==, !=, >=, <=
– block runs exclusively until completion unless doevents used (see 3.23)
usage: for(init_assignment;condition;step_assignment) block
– init_assignment and step_assignment are simple non-complex statement
valid: n0.val=4, sys2++, n0.val=sys2*4+3
invalid: n0.val=3+(sys2*4)-1// iterate n0.val by 1's as long asn0.val<100. result: n0.val=100 // will not visually see n0val increment until for-loop completes for(n0.val=0;n0.val<100;n0.val++) { } ////iterate n0.val by 2's as long as n0.val<100. result: n0.val=100 // will visually see n0.val increment when doevents processed for(n0.val=0;n0.val<100;n0.val+=2) { doevents }
- *K* wepo
Parameter Count 2
Store value/string to EEPROM
– EEPROM valid address range is from 0 to 1023 (1K EEPROM)
– numeric value length: is 4 bytes, -2147483648 to 2147483647
– numeric data type signed long integer, stored in little endian order.
val[addr+3]*16777216+val[addr+2]*65536+val[addr+1]*256+val[addr]– string content length: .txt content is .txt-maxl +1, or constant length +1
usage: wepo attr,addr
attr is variable or constant
addr is storage starting address in EEPROMwepo t0.txt,10// writes t0.txt contents in addresses 10 to 10+t0.txt-maxl wepo "abcd",10// write constant “abcd” in addresses 10 to 14 wepo 11,10// write constant 11 in addresses 10 to 13 wepo n0.val,10// write value n0.val in addresses 10 to 13
- *K* repo
Parameter Count 2
Read value from EEPROM
– EEPROM valid address range is from 0 to 1023 (1K EEPROM)
– numeric value length: is 4 bytes, -2147483648 to 2147483647
– numeric data type signed long integer, stored in little endian order.
val[addr+3]*16777216+val[addr+2]*65536+val[addr+1]*256+val[addr]– string content length: .txt content is lesser of .txt-maxl or until null reached.
usage: repo attr,addr
attr is variable or constant
addr is storage starting address in EEPROMrepo t0.txt,10// reads qty .txt-maxl chars (or until null) from 10 into t0.txt repo n0.val,10// reads 4 bytes from address 10 to 13 into n0.val
- *K* wept
Parameter Count 2
Store specified number of bytes to EEPROM over Serial from MCU
– EEPROM valid address range is from 0 to 1023 (1K EEPROM)
– wept uses Transparent Data Mode (see 1.16)
– qty limited by serial buffer (all commands+terminations + data < 1024)
usage: wept addr,qty
addr is storage starting address in EEPROM
qty is the number of bytes to storewept 30,20// writes 20 bytes into EEPROM addresses 30 to 49 from serial // byte of data is not ASCII text of byte value, but raw byte of data.
- *K* rept
Parameter Count 2
Read specified number of bytes from EEPROM over Serial to MCU
– EEPROM valid address range is from 0 to 1023 (1K EEPROM)
usage: rept addr,qty
addr is storage starting address in EEPROM
qty is the number of bytes to readrept 30,20// sends 20 bytes from EEPROM addresses 30 to 49 to serial // byte of data is not ASCII text of byte value, but raw byte of data.
- *K* cfgpio
Parameter Count 3
Configure Nextion GPIO
usage: cfgpio io,mode,comp
io is the number of the extended I/O pin.
– Valid values in PWM output mode: 4 to 7, all other modes 0 to 7.
mode is the working mode of pin selected by io.
– Valid values: 0-pull up input, 1-input binding, 2-push pull output,
3-PWM output, 4-open drain output.
comp component .objname or .id when is 1 (otherwise use 0)
– in binding mode, cfgpio needs to be declared after every refresh of page to reconnect to Touch event,
best to put cfgpio in page pre-initialization eventcfgpio 0,0,0// configures io0 as a pull-up input. Read as n0.val=pio0. cfgpio 1,2,0// configures io1 as a push-pull output, write as pio1=1 cfgpio 2,1,b0// configures io2 as binding input with current page b0. // binding triggers b0 Press on falling edge and b0 Release on rising edge For PWM mode, set duty cycle before cfgpio: ie: pwm4=20 for 20% duty. cfgpio 4,3,0// configures io4 as PWM output. pwmf=933 to change Hz. // changing pwmf changes frequency of all configured PWM io4 to io7
- ucopy
Parameter Count 4
Advanced. Read Only. Valid in active Protocol Reparse mode.
Copies data from the serial buffer.
When Nextion is in active Protocol Reparse mode, ucopy copies data from the serial buffer. Most HMI applications will not require Protocol Reparse and should be skipped if not fully understood.
usage: ucopy attr,srcstart,len,deststart
attr must be a writeable attribute ie: t0.txt, va0.val
srcstart must be numeric value ie: 0
len must be a numeric value ie: 4
deststart must be numeric value ie: 0ucopy n0.val,0,2,0// copy buffer bytes 0,1 to lower 2 bytes of n0.val ucopy n0.val,0,2,2// copy buffer bytes 0,1 to upper 2 bytes of n0.val ucopy n0.val,0,4,0// copy buffer bytes 0,1,2,4 to n0.val ucopy t0.txt,0,10,0// copy buffer bytes 0 to 9 into t0.txt
4. GUI Designing Instructions
- cls
Parameter Count 1
Clear the screen and fill the entire screen with specified color
usage: cls color
color is either decimal 565 Color Value or Color Constantcls BLUE// Clear the screen and fill with color BLUE cls 1024// Clear the screen and fill with color 1024
- pic
Parameter Count 3
Display a Resource Picture at specified coordinate
usage: pic x,y,picid
x is the x coordinate of upper left corner where picture should be drawn
y is the y coordinate of upper left corner where picture should be drawn
picid is the number of the Resource Picture in the HMI designpic 10,20,0// Display Resource Picture #0 with upper left corner at (10,20) pic 40,50,1// Display Resource Picture #1 with upper left corner at (40,50)
- picq
Parameter Count 5
Crop Picture area from Resource Picture using defined area
– replaces defined area with content from the same area of Resource Picture
– Resource Picture should be full screen-size or area might be undefined
usage: picq x,y,w,h,picid
x is the x coordinate of upper left corner of defined crop area
y is the y coordinate of upper left corner of defined crop area
w is the width of the defined crop area
h is the height of the defined crop area
picid is the number of the Resource Picture in the HMI designpicq 20,50,30,20,0 // crops area 30×20, from (20,50) to (49,69), from Resource Picture 0
- xpic
Parameter Count 7
Advanced Crop Picture
crop area from source Resource Picture render at destination coordinate
usage: xpic destx,desty,w,h,srcx,srcy,picid
destx is the x coordinate of destination upper left corner
desty is the y coordinate of destination upper left corner
w is the width of the defined crop area
h is the height of the defined crop area
srcx is the x coordinate of upper left corner of defined crop area
srcy is the y coordinate of upper left corner of defined crop area
picid is the number of the Resource Picture in the HMI designxpic 20,50,30,20,15,15,0// crops area 30×20, from (15,15) to (44,34), // from Resource Picture 0 and renders it with upper left corner at (20,50)
- xstr
Parameter Count 11
Prints text on the Nextion device using defined area for text rendering
usage xstr x,y,w,h,font,pco,bco,xcen,ycen,sta,text
x is the x coordinate of upper left corner of defined text area
y is the y coordinate of upper left corner of defined text area
w is the width of the defined text area
h is the height of the defined text area
font is the number of the Resource Font
pco is the foreground color of text (Color Constant or 565 color value)
bco is a) background color of text, or b) picid if sta is set to 0 or 2
xcen is the Horizontal Alignment (0 – left, 1 – centered, 2 – right)
ycen is the Vertical Alignment (0 – top/upper, 1 – center, 3 – bottom/lower)
sta is background Fill (0 – crop image, 1 – solid color, 2 – image, 3 – none)
text is the string content (constant or .txt attribute), ie "China", or va0.txtxstr 10,10,100,30,1,WHITE,GREEN,1,1,1,va0.txt // use are 100×30 from (10,10) to (109,39) to print contents of va0.txt using // Font Resource 1 rendering Green letters on White background with both // horizontal and vertical centering and sta set as solid-color.
- fill
Parameter Count 5
Fill a defined area with specified color
usage: fill x,y,w,h,color
x is the x coordinate of upper left corner of defined fill area
y is the y coordinate of upper left corner of defined fill area
w is the width of the defined fill area
h is the height of the defined fill area
color is fill color, either decimal 565 Color Value or Color Constantfill 20,20,150,50,1024 // fills area 150×50 from (20,20) to (169,69) with 565 Color 1024.
- line
Parameter Count 5
Draw a line from point to point with specified color
usage: x1,y1,x2,y2,color
x1 is the x coordinate of the starting point of the line to be drawn
y1 is the y coordinate of the starting point of the line to be drawn
x2 is the x coordinate of the ending point of the line to be drawn
y2 is the y coordinate of the ending point of the line to be drawn
color is line color, either decimal 565 Color Value or Color Constantline 20,30,170,200,BLUE// draws line in BLUE from (20,30) to (170,200)
- draw
Parameter Count 5
Draw a hollow rectangle around specified area with specified color
usage: draw x1,y1,x2,y2,color
x1 is the x coordinate of the upper left corner of rectangle area
y1 is the y coordinate of the upper left corner of rectangle area
x2 is the x coordinate of the lower right corner of rectangle area
y2 is the y coordinate of the lower right corner of rectangle area
color is line color, either decimal 565 Color Value or Color Constantdraw 10,10,70,70,GREEN// draw a Green rectangle around (10,10) to (79,79) // effectively four lines from (x1,y1) to (x2,y1) to (x2,y2) to (x1,y2) to (x1,y1)
- cir
Parameter Count 4
Draw a hollow circle with specified radius and specified color
usage: cir x,y,radius,color
x is the x coordinate of the center point for the circle
y is the y coordinate of the center point for the circle
radius is the radius in pixels
color is line color, either decimal 565 Color Value or Color Constantcir 100,100,30,RED// renders a hollow Red circle with circle center at (100,100), // a 30 pixel radius, a 61 pixel diameter, within boundary (70,70) to (130,130).
- cirs
Parameter Count 4
Draw a filled circle with specified radius and specified color
usage: circ x,y,radius,color
x is the x coordinate of the center point for the circle
y is the y coordinate of the center point for the circle
radius is the radius in pixels
color is fill color, either decimal 565 Color Value or Color Constantcir 100,100,30,RED// renders a filled Red circle with center at (100,100), // a 30 pixel radius, a 61 pixel diameter, within boundary (70,70) to (130,130).
No. | Constant | 565 Color Value | Indicator Color | Sample |
1 | BLACK | 0 | Black | |
2 | WHITE | 65535 | White | |
3 | BLUE | 31 | Blue | |
4 | GREEN | 2016 | Green | |
5 | RED | 63488 | Red | |
6 | GRAY | 33840 | Gray | |
7 | YELLOW | 65504 | Yellow | |
8 | BROWN | 48192 | Brown | |
Note: | 16-bit 565 Colors are in decimal values from 0 to 65535 Least significant bits are saturated 24-bit RGB 11011000 11011100 11011000 16-bit 565 11011111 11011011 10111111 |
- dp
Current Page IDdp=1 n0.val=dp
read: Contains the current page displayed as per the HMI design
write: change page to value specified (same effect as page command)
min 0, max # of highest existing page in user's HMI design - dim, dims
Nextion Backlightdim=32 dims=100
Sets the backlight level in percent
min 0, max 100, default 100 or user defined
Note: dim=32 will set the current backlight level to 32%.
using dims=32 will set the current backlight level to 32% and save this to be new power on default backlight level, persisting until changed. - baud, bauds
Nextion Baud Ratebaud=9600 bauds=9600
Sets the Nextion Baud rate in bits-per-second
min 2400, max 115200, default 9600 or user defined
Valid values are: 2400, 4800, 9600, 19200, 38400, 57600, and 115200.
Note: baud=38400 will set the current baud rate to 38400
using bauds=38400 will set the current baud rate to 38400 and save this to be new power on default baud rate, persisting until changed.
Note: on rare occasions bauds has become lost. It is recommended to specify bauds=9600 in the first page’s Preinitialization Event of HMI - spax, spay
Font Spacingspax=2 spay=2
Globally sets the default rendering space:
horizontally between font characters with spax additional pixels and
vertically between rows (if multi-lined) with spay additional pixels.
min 0, max 65535, default 0
Note: Components now have their own individual .spax/.spay attributes that are now used to determine spacing for the individual component. - thc
Touch Draw Brush Colorthc=RED thc=1024
Sets the Touch Drawing brush color
min 0, max 65535, default 0
Valid choices are either color constants or the decimal 565 color value - thdra
Touch Drawingthdra=1// (on) thdra=0// (off)
Turns the internal drawing function on or off.
min 0, max 1, default 0
When the drawing function is on, Nextion will follow touch dragging with the current brush color (as determined by the thc variable). - ussp
Sleep on No Serialussp=30
Sets internal No-serial-then-sleep timer to specified value in seconds
min 3, max 65535, default 0 (max: 18 hours 12 minutes 15 seconds)
Nextion will auto-enter sleep mode if and when this timer expires.
Note: ussp=0 is an invalid value, meaning once ussp is set, it will persist and can not be unset unless through reboot or reset. - thsp
Sleep on No Touchthsp=30
Sets internal No-touch-then-sleep timer to specified value in seconds
min 3, max 65535, default 0 (max: 18 hours 12 minutes 15 seconds)
Nextion will auto-enter sleep mode if and when this timer expires.
Note: thsp=0 is an invalid value, meaning once thsp is set, it will persist and can not be unset unless through reboot or reset - thup
Auto Wake on Touchthup=0// (do not wake) thup=1// (wake on touch)
Sets if Nextion should auto-wake from sleep when touch press occurs.
min 0, max 1, default 0
When value is 1 and Nextion is in sleep mode, the first touch will only trigger the auto wake mode and not trigger a Touch Event.
thup has no influence on sendxy, sendxy will operate independently. - sendxy
RealTime Touch Coordinatessendxy=1// (start sending) sendxy=0// (stop sending)
Sets if Nextion should send 0x67 and 0x68 Return Data
min 0, max 1, default 0
– as with any touch less accurate closer to edges, and more accurate closer to center.
Note: expecting exact pixel (0,0) or (799,479) is simply not achievable. - delay
Delaydelay=100
Creates a halt in Nextion code execution for specified time in ms
min 0, max 65535
As delay is interpreted, a total halt is avoided. Incoming serial data is received and stored in buffer but not be processed until delay ends. If delay of more than 65.535 seconds is required, use of multiple delay statements required.
delay=-1 is max. 65.535 seconds. - sleep
Sleepsleep=1// (Enter sleep mode) sleep=0// (Exit sleep mode)
min 0, max 1, default 0
When exiting sleep mode, the Nextion device will auto refresh the page
(as determined by the value in the wup variable) and reset the backlight brightness (as determined by the value in the dim variable) - bkcmd
Pass / Fail Return Databkcmd=3
Sets the level of Return Data on commands processed over Serial.
min 0, max 3, default 2
– Level 0 is Off – no pass/fail will be returned
– Level 1 is OnSuccess, only when last serial command successful.
– Level 2 is OnFailure, only when last serial command failed
– Level 3 is Always, returns 0x00 to 0x23 result of serial command.
Result is only sent after serial command/task has been completed, as such this provides an invaluable status for debugging and branching. Table 2 of Section 7 Nextion Return Data is not subject to bkcmd - rand
Random Valuen0.val=rand
Readonly. Value returned by rand is random every time it is referred to.
default range is 0 to 4294967295
range of rand is user customizable using the randset command
range as set with randset will persist until reboot or reset - sys0, sys1, sys2
Numeric System Variablessys0=10 sys1=40 sys2=60 n0.val=sys2
System Variables are global in nature with no need to define or create.
They can be read or written from any page. 32-bit unsigned integers.
min value of 0, max value of 4294967295
Suggested uses of sys variables include
– as temporary variables in complex calculations
– as parameters to pass to click function or pass between pages. - wup
Wake Up Pagewup=2 n0.val=wup
Sets which page Nextion loads when exiting sleep mode
min is 0, max is # of last page in HMI, default 255
When wup=255 (not set to any existing page)
- Nextion wakes up to current page, refreshing components only
wup can be set even when Nextion is in sleep mode - usup
Wake On Serial Datausup=0 usup=1
Sets if serial data wakes Nextion from sleep mode automatically.
min is 0, max is 1, default 0
When usup=0, send sleep=0ÿÿÿ to wake Nextion
When usup=1, any serial received wakes Nextion - *K* rtc0, rtc1, rtc2, rtc3, rtc4, rtc5, rtc6
Real Time Clockrtc0=2017 rtc1=8 rtc2=28 rtc3=16 rtc4=50 rtc5=36 n0.val=rtc6
Nextion RTC:
rtc0 is year 2000 to 2099, rtc1 is month 1 to 12, rtc2 is day 1 to 31,
rtc3 is hour 0 to 23, rtc4 is minute 0 to 59, rtc5 is second 0 to 59.
rtc6 is dayofweek 0 to 6 (Sunday=0, Saturday=6)
rtc6 is readonly and calculated by RTC when date is valid. - *K* pio0, pio1, pio2, pio3, pio4, pio5, pio6, pio7
Nextion GPIOpio3=1 pio3=0 n0.val=pio3
Default mode when power on: pull up input mode
Internal pull up resistor: 50K
GPIO is digital. Value of 0 or 1 only.
– refer to cfgpio command for setting GPIO mode
read if in input mode, write if in output mode - *K* pwm4, pwm5, pwm6, pwm7
PWM Duty Cyclepwm4=25
Value in percentage. min 0, max 100, default 50.
– refer to cfgpio command for setting GPIO mode - *K* pwmf
PWM Frequencypwmf=933
Value is in Hz. min value 1 Hz, max value 65535 Hz. default 1000 Hz
All PWM output is unified to only one Frequency, no independent individual settings are allowed.
– refer to cfgpio command for setting GPIO mode - addr
Addressaddr=257
Advanced. Enables/disables Nextion’s two byte Address Mode
0, or min value 256, max value 2815. default 0
Setting addr will persist to be the new power-on default.
– refer to section 1.19 - tch0, tch1, tch2, tch3
Realtime Touch Coordinatesx.val=tch0 y.val=tch1
Readonly. When Pressed tch0 is x coordinate, tch1 is y coordinate.
When released (not currently pressed), tch0 and tch1 will be 0.
tch2 holds the last x coordinate, tch3 holds the last y coordinate. - recmod
Protocol Reparse Moderecmod=0 recmod=1
Advanced. Set passive or active Protocol Reparse mode.
min is 0, max is 1, default 0
When recmod=0, Nextion is in passive mode and processes serial data according to the Nextion Instruction Set, this is the default power on processing. When recmod=1, Nextion enters into active mode where the serial data waits to be processed by event code. Most HMI applications will not require Protocol Reparse and should be skipped if not fully understood. - usize
Bytes in Serial Buffern0.val=usize
Advanced. Read Only. Valid in active Protocol Reparse mode.
min is 0, max is 1024
When Nextion is in active Protocol Reparse mode, usize reports the number of available bytes in the serial buffer. Most HMI applications will not require Protocol Reparse and should be skipped if not fully understood. - u[index]
Serial Buffer Datan0.val=u[0]
Advanced. Read Only. Valid in active Protocol Reparse mode.
min is 0, max is 255
When Nextion is in active Protocol Reparse mode, the u[index] array returns the byte at position index from the serial buffer. Most HMI applications will not require Protocol Reparse and should be skipped if not fully understood.
- 0x00
Invalid Instruction
Return Length: Fixed 4 bytes0x00 0xFF 0xFF 0xFF
Returned when instruction sent by user has failed
when bkcmd set to 2 or 3 - 0x01
Instruction Successful
Return Length: Fixed 4 bytes0x01 0xFF 0xFF 0xFF
Returned when instruction sent by user was successful
when bkcmd set to 1 or 3 - 0x02
Invalid Component ID
Return Length: Fixed 4 bytes0x02 0xFF 0xFF 0xFF
Returned when invalid Component ID or name was used
when bkcmd set to 2 or 3 - 0x03
Invalid Page ID
Return Length: Fixed 4 bytes0x03 0xFF 0xFF 0xFF
Returned when invalid Page ID or name was used
when bkcmd set to 2 or 3 - 0x04
Invalid Instruction
Return Length: Fixed 4 bytes0x04 0xFF 0xFF 0xFF
Returned when invalid Picture ID was used
when bkcmd set to 2 or 3 - 0x05
Invalid Font ID
Return Length: Fixed 4 bytes0x05 0xFF 0xFF 0xFF
Returned when invalid Font ID was used
when bkcmd set to 2 or 3 - 0x06
Invalid Timer ID
Return Length: Fixed 4 bytes0x06 0xFF 0xFF 0xFF
Returned when invalid Timer ID was used
when bkcmd set to 2 or 3 - 0x07
Invalid Timer configuration
Return Length: Fixed 4 bytes0x07 0xFF 0xFF 0xFF
Returned when unconfigured timer was used
when bkcmd set to 2 or 3 - 0x08
Invalid System Variable ID
Return Length: Fixed 4 bytes0x08 0xFF 0xFF 0xFF
Returned when invalid System Variable ID was used
when bkcmd set to 2 or 3 - 0x11
Invalid Baud rate Setting
Return Length: Fixed 4 bytes0x11 0xFF 0xFF 0xFF
Returned when invalid Baud rate was used
when bkcmd set to 2 or 3 - 0x12
Invalid Waveform ID or Channel #
Return Length: Fixed 4 bytes0x12 0xFF 0xFF 0xFF
Returned when invalid Waveform ID or Channel # was used
when bkcmd set to 2 or 3 - 0x1A
Invalid Variable name or attribute
Return Length: Fixed 4 bytes0x1A 0xFF 0xFF 0xFF
Returned when invalid Variable name or invalid attribute was used
when bkcmd set to 2 or 3 - 0x1B
Invalid Variable Operation
Return Length: Fixed 4 bytes0x1B 0xFF 0xFF 0xFF
Returned when Operation of Variable is invalid.
ie: Text assignment t0.txt=abc or t0.txt=23, Numeric assignment j0.val="50" or j0.val=abc
when bkcmd set to 2 or 3 - 0x1C
Assignment failed to assign
Return Length: Fixed 4 bytes0x1C 0xFF 0xFF 0xFF
Returned when attribute assignment failed to assign
when bkcmd set to 2 or 3 - *K* 0x1D
EEPROM Operation failed
Return Length: Fixed 4 bytes0x1D 0xFF 0xFF 0xFF
Returned when an EEPROM Operation has failed
when bkcmd set to 2 or 3 - 0x1E
Invalid Quantity of Parameters
Return Length: Fixed 4 bytes0x1E 0xFF 0xFF 0xFF
Returned when the number of instruction parameters is invalid
when bkcmd set to 2 or 3 - 0x1F
IO Operation failed
Return Length: Fixed 4 bytes0x1F 0xFF 0xFF 0xFF
Returned when an IO operation has failed
when bkcmd set to 2 or 3 - 0x20
Escape Character Invalid
Return Length: Fixed 4 bytes0x20 0xFF 0xFF 0xFF
Returned when an unsupported escape character is used
when bkcmd set to 2 or 3 - 0x21
IF comparison with non matched types
Return Length: Fixed 4 bytes0x21 0xFF 0xFF 0xFF
Returned two non-matching type used in an if comparison
when bkcmd set to 2 or 3 - 0x22
Instruction CRC Invalid
Return Length: Fixed 4 bytes0x22 0xFF 0xFF 0xFF
Returned when instruction CRC fails
when bkcmd set to 2 or 3 - 0x23
Variable name too long
Return Length: Fixed 4 bytes0x23 0xFF 0xFF 0xFF
Returned when variable name is too long. Max length is 29 characters: 14 for page + "." + 14 for component.
when bkcmd set to 2 or 3 - 0x00
Nextion Startup
Return Length: Fixed 6 bytes0x00 0x00 0x00 0xFF 0xFF 0xFF
Returned when Nextion has started or reset
Not effected by the bkcmd setting - 0x24
Serial Buffer Overflow
Return Length: Fixed 4 bytes0x24 0xFF 0xFF 0xFF
Returned when a Serial Buffer overflow occurs
Not effected by the bkcmd setting - 0x65
Touch Event
Return Length: Fixed 7 bytes0x65 0x00 0x02 0x01 0xFF 0xFF 0xFF
Returned when Touch occurs and component’s
corresponding Send Component ID is checked
in the users HMI design.
0x00 is page number, 0x02 is component ID,
0x01 is event (0x01 Press and 0x00 Release)
data: Page 0, Component 1, Pressed
Not effected by the bkcmd setting - 0x66
Current Page Number
Return Length: Fixed 5 bytes0x66 0x01 0xFF 0xFF 0xFF
Returned when the sendme command is used.
0x01 is current page number
data: page 1
Not effected by the bkcmd setting - 0x67
Touch Coordinate (awake)
Return Length: Fixed 9 bytes0x67 0x00 0x7A 0x00 0x1E 0x01 0xFF 0xFF 0xFF
Returned when sendxy=1 and not in sleep mode
0x00 0x7A is x coordinate in big endian order,
0x00 0x1E is y coordinate in big endian order,
0x01 is event (0x01 Press and 0x00 Release)
(0x00*256+0x71,0x00*256+0x1E)
data: (122,30) Pressed
Not effected by the bkcmd setting - 0x68
Touch Coordinate (sleep)
Return Length: Fixed 9 bytes0x68 0x00 0x7A 0x00 0x1E 0x01 0xFF 0xFF 0xFF
Returned when sendxy=1 and in sleep mode
0x00 0x7A is x coordinate in big endian order,
0x00 0x1E is y coordinate in big endian order,
0x01 is event (0x01 Press and 0x00 Release)
(0x00*256+0x71,0x00*256+0x1E)
data: (122,30) Pressed
Not effected by the bkcmd setting - 0x70
String Data Enclosed
Return Length: Varied number of bytes0x70 0x61 0x62 0x31 0x32 0x33 0xFF 0xFF 0xFF
Returned when using get command for a string.
Each byte is converted to char.
data: ab123
Not effected by the bkcmd setting - 0x71
Numeric Data Enclosed
Return Length: Fixed 8 bytes0x71 0x01 0x02 0x03 0x04 0xFF 0xFF 0xFF
Returned when get command to return a number
4 byte 32-bit value in little endian order.
(0x01+0x02*256+0x03*65536+0x04*16777216)
data: 67305985
Not effected by the bkcmd setting - 0x86
Auto Entered Sleep Mode
Return Length: Fixed 4 bytes0x86 0xFF 0xFF 0xFF
Returned when Nextion enters sleep automatically
Using sleep=1 will not return an 0x86
Not effected by the bkcmd setting - 0x87
Auto Wake from Sleep
Return Length: Fixed 4 bytes0x87 0xFF 0xFF 0xFF
Returned when Nextion leaves sleep automatically
Using sleep=0 will not return an 0x87
Not effected by the bkcmd setting - 0x88
Nextion Ready
Return Length: Fixed 4 bytes0x88 0xFF 0xFF 0xFF
Returned when Nextion has powered up
and is now initialized successfully
Not effected by the bkcmd setting - 0x89
Start microSD Upgrade
Return Length: Fixed 4 bytes0x89 0xFF 0xFF 0xFF
Returned when power on detects inserted microSD
and begins Upgrade by microSD process
Not effected by the bkcmd setting - 0xFD
Transparent Data Finished
Return Length: Fixed 4 bytes0xFD 0xFF 0xFF 0xFF
Returned when all requested bytes of Transparent
Data mode have been received, and is now leaving transparent data mode (see 1.16)
Not effected by the bkcmd setting - 0xFE
Transparent Data Ready
Return Length: Fixed 4 bytes0xFE 0xFF 0xFF 0xFF
Returned when requesting Transparent Data
mode, and device is now ready to begin receiving
the specified quantity of data (see 1.16)
Not effected by the bkcmd setting
= Assignment Text 2.1, Numeric 2.7
+= Addition Text 2.2, Numeric 2.8
-= Subtraction Text 2.3, Numeric 2.9
\ Escape character 2.4
== Boolean Equality Text 2.5, Numeric 2.17
!= Boolean Inequality Text 2.6, Numeric 2.18
*= Multiplication Numeric, 2.10
/= Division Numeric, 2.11
%= Modulo Division Numeric, 2.12
<< Logical Shift Left Numeric, 2.13
>> Logical Shift Right Numeric, 2.14
&Logical AND Numeric, 2.15
| Logical OR Numeric, 2.16
< . Boolean Less than Numeric, 2.19
<= Boolean Less than Equal Numeric, 2.20
> . Boolean Greater than Numeric, 2.21
>= Boolean Greater than Equal Numeric, 2.22
{ } Code Block Brace, 2.23
( ) Code Block Condition, 2.24
. Code Period Seperator, 2.25
[ ] Code Array[index], 2.26
// Comment, 2.27
0x00 Invalid Instruction, 7.1
0x00 Invalid Instruction, 7.17
0x01 Instruction Successful, 7.2
0x02 Invalid Component ID, 7.3
0x03 Invalid Page ID, 7.4
0x04 Invalid Picture ID, 7.5
0x05 Invalid Font ID, 7.6
0x11 Invalid Baud rate Setting, 7.7
0x12 Invalid Waveform ID or Channel #, 7.8
0x1A Invalid Variable name or attribute, 7.9
0x1B Invalid Variable Operation, 7.10
0x1C Assignment failed to assign, 7.11
0x1D EEPROM Operation failed, 7.12
0x1E Invalid Quantity of Parameters, 7.13
0x1F IO Operation failed, 7.14
0x20 Escape Character Invalid, 7.15
0x23 Variable name too long, 7.16
0x24 Serial Buffer Overflow, 7.18
0x65 Touch Event, 7.14
0x66 Current Page Number, 7.20
0x67 Touch Coordinate (awake), 7.21
0x68 Touch Coordinate (sleep), 7.22
0x70 String Data Enclosed, 7.23
0x71 Numeric Data Enclosed, 7.24
0x86 Auto Entered Sleep Mode, 7.25
0x87 Auto Wake from Sleep, 7.26
0x88 Nextion Ready, 7.27
0x89 Start microSD Upgrade, 7.28
0xFD Transparent Data Finished, 7.29
0xFE Transparent Data Ready, 7.30
add Add a value to Waveform, 3.19
addr Address, 6.22
addt Add many values to Waveform, 3.20
baud Nextion Baud Rate, 6.3
bauds Nextion Baud Rate, 6.3
bkcmd Pass/Fail Return Data, 6.13
BLACK Black Constant, 5.1
BLUE Blue Constant, 5.3
BROWN Brown Constant, 5.8
btlen String Length double-byte, 3.24
cfgpio Configure Nextion GPIO, 3.22
cir GUI Draw Hollow Circle, 4.9
cirs GUI Draw Hollow Circle, 4.10
cle Clear Waveform Channel, 3.21
click Trigger Touch Event, 3.3
cls GUI Clear Screen, 4.1
code_c Clear Serial Buffer, 3.16
com_stop Serial Execution Stop, 3.13
com_star Serial Execution Resume, 3.14
cov Convert Value to/from Text, 3.8
covx Convert Value to/from Text, 3.8
delay Delay, 6.11
dim Nextion Backlight, 6.2
dims Nextion Backlight, 6.2
doevents Force Refresh, 3.23
dp Current Page ID, 6.1
draw GUI Draw Hollow Rectangle, 4.8
fill GUI Draw Solid Rectangle, 4.6
for for Iteration Loop Block, 3.27
get Send Serial Attribute Value, 3.6
GRAY Gray Constant, 5.6
GREEN Green Constant, 5.4
if Conditional Block, 3.25
line GUI Draw Line, 4.7
page Change Page, 3.1
pic GUI Display Picture, 4.2
picq GUI Crop Picture, 4.3
pio0 Nextion GPIO, 6.19
pio1 Nextion GPIO, 6.19
pio2 Nextion GPIO, 6.19
pio3 Nextion GPIO, 6.19
pio4 Nextion GPIO, 6.19
pio5 Nextion GPIO, 6.19
pio6 Nextion GPIO, 6.19
pio7 Nextion GPIO, 6.19
print Print to Serial, 3.17
printh Print HEX to Serial, 3.18
prints Print to Serial, 3.17
pwm4 PWM Duty Cycle, 6.20
pwm5 PWM Duty Cycle, 6.20
pwm6 PWM Duty Cycle, 6.20
pwm7 PWM Duty Cycle, 6.20
pwmf PWM Frequency, 6.21
rand Random Value, 6.14
randset Random Generator Range, 3.15
recmod Protocol Reparse Mode, 6.24
RED Red Constant, 5.5
ref Refresh Component, 3.2
ref_stop Waveform Refresh Stop, 3.4
ref_star Waveform Refresh Resume, 3.5
repo Restore from EEPROM single value, 3.29
rept Restore from EEPROM multi value, 3.31
rest Reset Nextion, 3.22
rtc0 Real Time Clock, 6.18
rtc1 Real Time Clock, 6.18
rtc2 Real Time Clock, 6.18
rtc3 Real Time Clock, 6.18
rtc4 Real Time Clock, 6.18
rtc5 Real Time Clock, 6.18
rtc6 Real Time Clock, 6.18
sendme Send Serial Current Page, 3.7
sendxy RealTime Touch Coordinates, 6.10
sleep Sleep, 6.12
spax Font Spacing, 6.4
spay Font Spacing, 6.4
strlen String Length single-byte, 3.24
substr SubString, 3.10
sys0 Numeric System Variables, 6.15
sys1 Numeric System Variables, 6.15
sys2 Numeric System Variables, 6.15
tch0 Realtime Touch Coordinates, 6.23
tch1 Realtime Touch Coordinates, 6.23
tch2 Realtime Touch Coordinates, 6.23
tch3 Realtime Touch Coordinates, 6.23
thc Touch Draw Brush Color, 6.5
thdra Touch Drawing, 6.6
thsp Sleep on No Touch, 6.8
thup Auto Wake on Touch, 6.9
touch_j Resistive Touch Calibration, 3.9
tsw Enable/Disable Component Touch, 3.12
u[index] Serial Buffer Data, 6.26
ucopy Copy from Serial Buffer, 3.33
usize Bytes in Serial Buffer, 6.25
ussp Sleep on No Serial, 6.7
usup Wake On Serial Data, 6.17
vis Hide/Show Component, 3.11
wepo Store to EEPROM single value, 3.28
wept Store to EEPROM multi value, 3.30
while while Conditional Block, 3.26
WHITE White Constant, 5.2
wup Wake Up Page, 6.16
xpic GUI Advanced Crop Picture, 4.4
xstr GUI Display Text, 4.5
YELLOW Yellow Constant, 5.7