Touch Panel Library

The mikroPascal PRO for dsPIC30/33 and PIC24 provides a library for working with Touch Panel.

Library Dependency Tree

External dependencies of Touch Panel Library

The following variables must be defined in all projects using Touch Panel Library:	Description :	Example :
`var DriveA : sbit; sfr; external;`	DriveA line.	`var DriveA : sbit at LATC13_bit;`
`var DriveB : sbit; sfr; external;`	DriveB line.	`var DriveB : sbit at LATC14_bit;`
`var DriveA_Direction : sbit; sfr; external;`	Direction of the DriveA pin.	`var DriveA_Direction : sbit at TRISC13_bit;`
`var DriveB_Direction : sbit; sfr; external;`	Direction of the DriveB pin.	`var DriveB_Direction : sbit at TRISC14_bit;`

TP_Init

Prototype	procedure TP_Init(display_width : word; display_height : word; readX_ChNo : byte; readY_ChNo : byte);
Description	Initialize touch panel display. Default touch panel ADC threshold value is set to 3900.
Parameters	`display_width:` set display width. `display_height:` set display height. `readX_ChNo:` read X coordinate from desired ADC channel. `readY_ChNo:` read Y coordinate from desired ADC channel.
Returns	Nothing.
Requires	Before calling this function initialize ADC module.
Example	ADC1_Init(); // Initalize ADC module TP_Init(128, 64, 6, 7); // Initialize touch panel, dimensions 128x64
Notes	None.

TP_Set_ADC_Threshold

Prototype	procedure TP_Set_ADC_Threshold(threshold : word);
Description	Set custom ADC threshold value, call this function after `TP_Init`.
Parameters	`threshold:` custom ADC threshold value.
Returns	Nothing.
Requires	`TP_Init` has to be called before using this routine.
Example	TP_Set_ADC_Threshold(3900); // Set touch panel ADC threshold
Notes	None.

TP_Press_Detect

Prototype	function TP_Press_Detect() : byte;
Description	Detects if the touch panel has been pressed.
Parameters	None.
Returns	`1` - if touch panel is pressed. `0` - otherwise.
Requires	Global variables : `DriveA:` DriveA. `DriveB:` DriveB. `DriveA_Direction:` Direction of DriveA pin. `DriveB_Direction:` Direction of DriveB pin. must be defined before using this function.
Example	// Touch Panel module connections var DriveA : sbit at LATC13_bit; DriveB : sbit at LATC14_bit; DriveA_Direction : sbit at TRISC13_bit; DriveB_Direction : sbit at TRISC14_bit; // End Touch Panel module connections if (TP_Press_Detect() <> 0) then begin ... end;
Notes	None.

TP_Get_Coordinates

Prototype	function TP_Get_Coordinates(x_coordinate : ^word; y_coordinate : ^word) : byte;
Description	Get touch panel coordinates and store them in `x_coordinate` and `y_coordinate` parameters.
Parameters	`x_coordinate:` x coordinate of the place of touch. `y_coordinate:` y coordinate of the place of touch.
Returns	`0` - if reading is within display dimension range. `1` - if reading is out of display dimension range.
Requires	Nothing.
Example	if (TP_Get_Coordinates(@x_coord, @y_coord) = 0) then begin ... end;
Notes	None.

TP_Calibrate_Bottom_Left

Prototype	procedure TP_Calibrate_Bottom_Left();
Description	Calibrate bottom left corner of the touch Panel.
Parameters	None.
Returns	Nothing.
Requires	Nothing.
Example	TP_Calibrate_Bottom_Left(); // Calibration of bottom left corner
Notes	None.

TP_Calibrate_Upper_Right

Prototype	procedure TP_Calibrate_Upper_Right();
Description	Calibrate upper right corner of the touch Panel.
Parameters	None.
Returns	Nothing.
Requires	Nothing.
Example	TP_Calibrate_Upper_Right(); // Calibration of upper right corner
Notes	None.

TP_Get_Calibration_Consts

Prototype	procedure TP_Get_Calibration_Consts(x_min : ^word; x_max : ^word; y_min : ^word; y_max : ^word);
Description	Gets calibration constants after calibration is done and stores them in `x_min`, `x_max`, `y_min` and `y_max` parameters.
Parameters	`x_min:` x coordinate of the bottom left corner of the working area. `x_max:` x coordinate of the upper right corner of the working area. `y_min:` y coordinate of the bottom left corner of the working area. `y_max:` y coordinate of the upper right corner of the working area.
Returns	Nothing.
Requires	Nothing.
Example	TP_Get_Calibration_Consts(@x_min, @y_min, @x_max, @y_max); // Get calibration constants
Notes	None.

TP_Set_Calibration_Consts

Prototype	procedure TP_Set_Calibration_Consts(x_min : word; x_max : word; y_min : word; y_max : word);
Description	Sets calibration constants.
Parameters	`x_min:` x coordinate of the bottom left corner of the working area. `x_max:` x coordinate of the upper right corner of the working area. `y_min:` y coordinate of the bottom left corner of the working area. `y_max:` y coordinate of the upper right corner of the working area.
Returns	Nothing.
Requires	Nothing.
Example	TP_Set_Calibration_Consts(148, 3590, 519, 3370); // Set calibration constants
Notes	None.

Library Example

The following drawing demo tests routines of the Touch Panel library :

Copy Code To Clipboard

program TouchPanelCalibrationAndWrite;

// Glcd module connections
var GLCD_D7 : sbit at RD3_bit;
    GLCD_D6 : sbit at RD2_bit;
    GLCD_D5 : sbit at RD1_bit;
    GLCD_D4 : sbit at RD0_bit;
    GLCD_D3 : sbit at RB3_bit;
    GLCD_D2 : sbit at RB2_bit;
    GLCD_D1 : sbit at RB1_bit;
    GLCD_D0 : sbit at RB0_bit;
    GLCD_D7_Direction : sbit at TRISD3_bit;
    GLCD_D6_Direction : sbit at TRISD2_bit;
    GLCD_D5_Direction : sbit at TRISD1_bit;
    GLCD_D4_Direction : sbit at TRISD0_bit;
    GLCD_D3_Direction : sbit at TRISB3_bit;
    GLCD_D2_Direction : sbit at TRISB2_bit;
    GLCD_D1_Direction : sbit at TRISB1_bit;
    GLCD_D0_Direction : sbit at TRISB0_bit;

var GLCD_CS1 : sbit at LATB4_bit;
    GLCD_CS2 : sbit at LATB5_bit;
    GLCD_RS  : sbit at LATF0_bit;
    GLCD_RW  : sbit at LATF1_bit;
    GLCD_EN  : sbit at LATF4_bit;
    GLCD_RST : sbit at LATF5_bit;

var GLCD_CS1_Direction : sbit at TRISB4_bit;
    GLCD_CS2_Direction : sbit at TRISB5_bit;
    GLCD_RS_Direction  : sbit at TRISF0_bit;
    GLCD_RW_Direction  : sbit at TRISF1_bit;
    GLCD_EN_Direction  : sbit at TRISF4_bit;
    GLCD_RST_Direction : sbit at TRISF5_bit;
// End Glcd module connections

// Touch Panel module connections
var DriveA : sbit at LATC13_bit;
    DriveB : sbit at LATC14_bit;
    DriveA_Direction : sbit at TRISC13_bit;
    DriveB_Direction : sbit at TRISC14_bit;
// end Touch Panel module connections

var write_erase : bit;
    pen_size : byte;
    x_coord, y_coord : word;
    write_msg, clear_msg, erase_msg : array[5] of char;      // GLCD menu messages

procedure Initialize();
  begin
    ADPCFG := 0xFF3F;                                        // set AN6 and AN7 channel pins as analog

    DriveA_Direction := 0;                                   // Set DriveA pin as output
    DriveB_Direction := 0;                                   // Set DriveB pin as output

    Glcd_Init();                                             // Initialize GLCD
    Glcd_Fill(0);                                            // Clear GLCD

    ADC1_Init();                                             // Initialize ADC
    TP_Init(128, 64, 6, 7);                                  // Initialize touch panel
    TP_Set_ADC_Threshold(3900);                              // Set touch panel ADC threshold
  end;

procedure Calibrate();
  begin
    Glcd_Dot(0,63,1);                                        // Draw bottom left dot
    Glcd_Write_Text('TOUCH BOTTOM LEFT',12,3,1);
    TP_Calibrate_Bottom_Left();                              // Calibration of bottom left corner
    Delay_ms(1000);

    Glcd_Dot(0,63,0);                                        // Clear bottom left dot
    Glcd_Dot(127,0,1);                                       // Draw upper right dot
    Glcd_Write_Text('                 ',12,3,1);
    Glcd_Write_Text('TOUCH UPPER RIGHT',12,4,1);
    TP_Calibrate_Upper_Right();                              // Calibration of upper right corner
    Delay_ms(1000);
  end;

begin
  write_msg := 'WRITE';
  clear_msg := 'CLEAR';
  erase_msg := 'ERASE';

  Initialize();

  Glcd_Fill(0);                                              // Clear GLCD
  Glcd_Write_Text('CALIBRATION',12,3,1);
  Delay_ms(1000);
  Glcd_Fill(0);                                              // Clear GLCD
  Calibrate();
  Glcd_Fill(0);

  Glcd_Write_Text('WRITE ON SCREEN', 20, 5, 1) ;
  Delay_ms(1000);
  Glcd_Fill(0);

  Glcd_V_Line(0,7,0,1);
  Glcd_Write_Text(clear_msg,1,0,0);
  Glcd_V_Line(0,7,97,1);
  Glcd_Write_Text(erase_msg,98,0,0);

  // Pen Menu:
  Glcd_Rectangle(41,0,52,9,1);
  Glcd_Box(45,3,48,6,1);
  Glcd_Rectangle(63,0,70,7,1);
  Glcd_Box(66,3,67,4,1);
  Glcd_Rectangle(80,0,86,6,1);
  Glcd_Dot(83,3,1);

  write_erase := 1;
  pen_size := 1;

  while (TRUE) do
    begin

      if (TP_Press_Detect() <> 0) then
        begin
          // After a PRESS is detected read X-Y and convert it to 128x64 space
          if (TP_Get_Coordinates(@x_coord, @y_coord) = 0) then
            begin
              if ((x_coord < 31) and (y_coord < 8)) then
                begin
                  Glcd_Fill(0);

                  // Pen Menu:
                  Glcd_Rectangle(41,0,52,9,1);
                  Glcd_Box(45,3,48,6,1);
                  Glcd_Rectangle(63,0,70,7,1);
                  Glcd_Box(66,3,67,4,1);
                  Glcd_Rectangle(80,0,86,6,1);
                  Glcd_Dot(83,3,1);

                  Glcd_V_Line(0,7,0,1);
                  Glcd_Write_Text(clear_msg,1,0,0);
                  Glcd_V_Line(0,7,97,1);
                  if (write_erase) then
                    Glcd_Write_Text(erase_msg,98,0,0)
                  else
                    Glcd_Write_Text(write_msg,98,0,0);
                end;

              // If write/erase is pressed
              if ((x_coord > 96) and (y_coord < 8)) then
                begin
                  if (write_erase) then
                    begin
                      write_erase := 0;
                      Glcd_Write_Text(write_msg,98,0,0);
                      Delay_ms(500);
                    end
                  else
                    begin
                      write_erase := 1;
                      Glcd_Write_Text(erase_msg,98,0,0);
                      Delay_ms(500);
                    end;
                end;

              // If pen size is selected
              if ((x_coord >= 41) and (x_coord <= 52) and (y_coord <= 9)) then
                pen_size := 3;

              if ((x_coord >= 63) and (x_coord <= 70) and (y_coord <= 7)) then
                pen_size := 2;

              if ((x_coord >= 80) and (x_coord <= 86) and (y_coord <= 6)) then
                pen_size := 1;

              if (y_coord < 11) then
                continue;

              case pen_size of
                1: if ( (x_coord >= 0) and (y_coord >= 0) and (x_coord <= 127) and (y_coord <= 63) ) then
                     Glcd_Dot(x_coord, y_coord, write_erase);

                2: if ( (x_coord >= 0) and (y_coord >= 0) and (x_coord <= 127-1) and (y_coord <= 63-1) ) then
                     Glcd_Box(x_coord, y_coord, x_coord + 1, y_coord + 1, write_erase);


                3: if ( (x_coord >= 1) and (y_coord >= 1) and (x_coord <= 127-2) and (y_coord <= 63-2) ) then
                     Glcd_Box(x_coord-1, y_coord-1, x_coord + 2, y_coord + 2, write_erase);

              end;
            end;
        end;
    end;
end.

Want more examples and libraries?
Find them on