NEXTION Controllers

This section covers GLCD devices that use the serially attached Nextion graphics displays.

Nextion includes hardware part (a series of TFT boards) and software part (the Nextion editor (http://nextion.itead.cc/)).

The Nextion TFT board uses only one serial port to communicate.   It lets you avoid the hassle of wiring.  Nextion editor has mass components such as button, text, progress bar, slider, instrument panel etc. to enrich your interface design.   And, the drag-and-drop function ensures that you spend less time in programming

The Nextion displays are 2.4 to 7.0 inches and range from 320*240 to 800*480 pixels.   The connections are 5v, 0v, SerialIn and SerialOut.   GCBASIC supports hardware and software serial connectivity.

See GITHUB for the set of GCBASIC demonstrations fro the Nextion displays. See Nextion demonstrations on GITHUB.





To use the Nextion driver simply include the following in your user code. This will initialise the driver.

Setup for Hardware Serial

' ----- Configuration
    'Chip Settings.
    #chip 16f18855,32
    #option explicit

' ----- Set up the Nextion GLCD
    #include <glcd.h>
    #define GLCD_TYPE GLCD_TYPE_Nextion


    ;VERY IMPORTANT!!
    ;Change the width and height to match the rotation in the Nextion Editor
    #define GLCD_WIDTH  320   'could be 320 | 400 | 272 | 480 but any valid dimension will work.
    #define GLCD_HEIGHT 240  'could be 240 | 480 | 800 but any valid dimension will work.


    ;VERY IMPORTANT!!
    ;Fonts installed in the Nextion MUST match the fonts parameters loading to the GLCD.
    ;Obtain parameters from Nextion Editor/Font dialog.
    #define NextionFont0      0, 8, 16    'Arial 8x16
    #define NextionFont1      1, 12, 24   '24point 12x24 charset
    #define NextionFont2      2, 16, 32   '32point 16x32 charset

' ----- End of set up for Nextion GLCD

' ----- Set up for Hardware Serial
    ;VERY IMPORTANT!!
    ;The Nextion MUST be setup for 9600 bps.
    #define USART_BAUD_RATE 9600
    #define USART_BLOCKING

    ;VERY IMPORTANT!!
    ;These two are optional. These constants are set in the library.
    #define GLCD_NextionSerialPrint HSerPrint
    #define GLCD_NextionSerialSend  HSerSend

' ----- End of set up for Serial


    'Generated by PIC PPS Tool for GCBASIC
    'PPS Tool version: 0.0.5.11
    'PinManager data: v1.55
    '
    'Template comment at the start of the config file
    '
    #startup InitPPS, 85

    Sub InitPPS

            'Module: EUSART
            RXPPS = 0x0016    'RC6 > RX

            'Module: EUSART
            RC0PPS = 0x0010    'TX > RC0
            TXPPS = 0x0010    'RC0 > TX (bi-directional)
            RC5PPS = 0x0010    'TX > RC5
            TXPPS = 0x0015    'RC5 > TX (bi-directional)

    End Sub
    'Template comment at the end of the config file


' ----- Main program starts
....



Setup for Software Serial

' ----- Configuration
    'Chip Settings.
    #chip 16f18855,32
    #option explicit

' ----- Set up the Nextion GLCD
    #include <glcd.h>
    #define GLCD_TYPE GLCD_TYPE_Nextion


    ;VERY IMPORTANT!!
    ;Change the width and height to match the rotation in the Nextion Editor
    #define GLCD_WIDTH  320   'could be 320 | 400 | 272 | 480 but any valid dimension will work.
    #define GLCD_HEIGHT 240  'could be 240 | 480 | 800 but any valid dimension will work.


    ;VERY IMPORTANT!!
    ;Fonts installed in the Nextion MUST match the fonts parameters loading to the GLCD.
    ;Obtain parameters from Nextion Editor/Font dialog.
    #define NextionFont0      0, 8, 16    'Arial 8x16
    #define NextionFont1      1, 12, 24   '24point 12x24 charset
    #define NextionFont2      2, 16, 32   '32point 16x32 charset

' ----- End of set up for Nextion GLCD

' ----- Set up for Software Serial - this is optional - shown to explain the method.
    ;Remove Hardware Serial before using Software serial
    ;You MUST also remove PPS setup, for hardware serial, when using Software serial
    #include <SoftSerial.h>

    ; ----- Config Serial UART for sending:
    #define SER1_BAUD 9600     ; baudrate must be defined
    #define SER1_TXPORT PORTC ; I/O port (without .bit) must be defined
    #define SER1_TXPIN 5       ; portbit  must be defined

    ;VERY IMPORTANT!!
    ;These two constants are required to support the the library.
    #define GLCD_NextionSerialPrint        Ser1Print
    #define GLCD_NextionSerialSend         Ser1Send
'
' ----- End of set up for Serial

' ----- Main program starts



The GCBASIC constants shown below control the configuration of the Nextion controller.    The GCBASIC constants for control and data line connections are shown in the table below.



Constants Controls Options

GLCD_TYPE

GLCD_TYPE_Nextion

  

GLCD_NextionSerialPrint

Default is HSerPrint for hardware serial can be SernPrint when using software serial.

Required

GLCD_NextionSerialSend

Default is HSerSend for hardware serial can be SernSend when using software serial.

Required



The GCBASIC constants for control display characteristics are shown in the table below.

Constants Controls Default

GLCD_WIDTH

Mandated. The width parameter of the GLCD

320

GLCD_HEIGHT

Mandated. The height parameter of the GLCD

480



The GCBASIC Nextion specific commands supported for this GLCD are shown in the table below.   Always review the appropiate library for the latest full set of supported commands.

Command Purpose Example

GLCDPrint_Nextion

Print string of characters on GLCD using Nextion font set

GLCDPrint( Xposition, Yposition, Stringvariable [,NextionFont] )

GLCDLocateString_Nextion

Locate the screen coordinates at a specific location.

GLCDLocateString_Nextion( Xposition, Yposition)

GLCDPrintString_Nextion

Print string of characters on GLCD using Nextion font set

GLCDPrintString_Nextion( Stringvariable )

GLCDPrintStringLn_Nextion

Print string of characters on GLCD using Nextion font set adding a newline and carriage return to move cursort to start of next line.

GLCDPrintStringLn_Nextion( Stringvariable )

GLCDSendOpInstruction_Nextion

Send the Nextion display a specific command and a specific value

GLCDSendOpInstruction_Nextion( Nextion_command, command_value )

GLCDUpdateObject_Nextion

Update a Nextion display object with a specific value

GLCDUpdateObject_Nextion( Nextion_object, object_value )

myReturnedWordValue = GLCDGetTouch_Nextion( "nextion_command_string" )

A function that returns a long, that can be treated as word variable, value of the Touch event..  As follows:

"tch0" for current x co-ordinate touched

"tch1" for current y co-ordinate touched

"tch2" for last x co-ordinate touched

"tch3" for last y co-ordinate touched

The function is non-blocking.

1. Checks for three bytes of 0xFF. If Four 0xff are received then exit = non-block.

2. If at any time a 0x71 is recieved then we have data for the event.

3. If seven bytes arrive, but the method did not receive a 0x71 then exit = non-block.

4. The method supports software and hardware serial. As does all the other methods.

5. The method uses a function to receive the data not a sub-routine.

6. The method returns 0xBEEF if there is an invalid read, and, functional value for GLCDGetTouch_Nextion will also be set to 0xDEADBEEF

myReturnedWordValue = GLCDGetTouch_Nextion( "tch2")

or,

myReturnedWordValue = GLCDGetTouch_Nextion( "tch3")



The GCBASIC commonn commands supported for this GLCD are shown in the table below.   Always review the appropiate library for the latest full set of supported commands.

Command Purpose Example

GLCDCLS

Clear screen of GLCD

GLCDCLS [,Optional LineColour]

GLCDPrint

Print string of characters on GLCD using GCB font set

GLCDPrint( Xposition, Yposition, Stringvariable )

GLCDDrawChar

Print character on GLCD using GCB font set

GLCDDrawChar( Xposition, Yposition, CharCode [,Optional LineColour] )

GLCDDrawString

Print characters on GLCD using GCB font set

GLCDDrawString( Xposition, Yposition, Stringvariable [,Optional LineColour] )

Box

Draw a box on the GLCD to a specific size

Box ( Xposition1, Yposition1, Xposition2, Yposition2 [,Optional LineColour]

FilledBox

Draw a box on the GLCD to a specific size that is filled with the foreground colour.

FilledBox (Xposition1, Yposition1, Xposition2, Yposition2 [,Optional LineColour] )

Line

Draw a line on the GLCD to a specific length that is filled with the specific attribute.

Line ( Xposition1, Yposition1, Xposition2, Yposition2 [,Optional LineColour] )

 



    TFT_BLACK   'hexidecimal value 0x0000
    TFT_RED     'hexidecimal value 0xF800
    TFT_GREEN   'hexidecimal value 0x0400
    TFT_BLUE    'hexidecimal value 0x001F
    TFT_WHITE   'hexidecimal value 0xFFFF
    TFT_PURPLE  'hexidecimal value 0xF11F
    TFT_YELLOW  'hexidecimal value 0xFFE0
    TFT_CYAN    'hexidecimal value 0x07FF
    TFT_D_GRAY  'hexidecimal value 0x528A
    TFT_L_GRAY  'hexidecimal value 0x7997
    TFT_SILVER  'hexidecimal value 0xC618
    TFT_MAROON  'hexidecimal value 0x8000
    TFT_OLIVE   'hexidecimal value 0x8400
    TFT_LIME    'hexidecimal value 0x07E0
    TFT_AQUA    'hexidecimal value 0x07FF
    TFT_TEAL    'hexidecimal value 0x0410
    TFT_NAVY    'hexidecimal value 0x0010
    TFT_FUCHSIA 'hexidecimal value 0xF81F





For more help, see GLCDCLS

Supported in <GLCD.H>

Prev  Up  Next
  Home