Syntax:
ADS7843_Init
ADS7843_GetXY
ADS7843_SetPrecisionCommand Availability:
Available on all microcontrollers. Requires the inclusion of the following:
#include <ADS7843.h>
Explanation:
The ADS7843 device is a 12-bit sampling Analog-to-Digital Converter (ADC) with a synchronous serial interface and low on resistance switches for driving touch screens.
The GCBASIC driver is integrated with the SDD1289 GLCD driver. To use the ADS7843 driver the following is required to added to the GCBASIC source file.
ADS7843_Init is required to initialise the touch screen. This is mandated.
ADS7843_GetXY this sub-routine returns the X and Y coordinates of touched point.
ADS7843_SetPrecision this sub-routine sets the level of precision of the touch screen.
Required Constants:
| Constants | Controls/Direction | Default Value |
|---|---|---|
|
ADS7843_DOUT (IN) |
The chip output pin |
Mandated |
|
ADS7843_IRQ (IN) |
The interrupt pin |
Mandated |
|
ADS7843_CS (OUT) |
The chip select pin |
Mandated |
|
ADS7843_CLK (OUT) |
The clock pin |
Mandated |
|
ADS7843_DIN (OUT) |
The chip input pin |
Mandated |
The GCBASIC commands supported for this chip are:
| Command | Purpose | Example |
|---|---|---|
|
ADS7843_Init |
Initialise the device. |
ADS7843_Init [Optional precision = PREC_EXTREME] |
|
ADS7843_GetXY |
Returns the X and Y coordinates of touched point. |
ADS7843_GetXY (TP_X, TP_Y ) |
|
ADS7843_SetPrecision |
Set the precision of the conversion result. |
ADS7843_SetPrecision(precision) |
Precision can be set to four values as shown in the table below. Passing a parameter of ADS7843_SetPrecision changes the precision controls.
| Constants | Defined Value | Default Value |
|---|---|---|
|
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Default Value |
Example:
For more information see http://www.ti.com/product/ads7843.
This example shows how to drive a SDD1289 based Graphic LCD module with ADS7843 touch controller.
'Chip Settings
#chip mega2560, 16
'Include for GLCD
#include <glcd.h>
'Include for ADS7843
#include <ADS7843.h>
'GLCD Device Selection
#DEFINE GLCD_TYPE GLCD_TYPE_SSD1289
'Define ports for the SSD1289 display - ALL are required
#DEFINE GLCD_WR PORTG.2
#DEFINE GLCD_CS PORTG.1
#DEFINE GLCD_RS PORTD.7
#DEFINE GLCD_RST PORTG.0
#DEFINE GLCD_DB0 PORTC.0
#DEFINE GLCD_DB1 PORTC.1
#DEFINE GLCD_DB2 PORTC.2
#DEFINE GLCD_DB3 PORTC.3
#DEFINE GLCD_DB4 PORTC.4
#DEFINE GLCD_DB5 PORTC.5
#DEFINE GLCD_DB6 PORTC.6
#DEFINE GLCD_DB7 PORTC.7
#DEFINE GLCD_DB8 PORTA.0
#DEFINE GLCD_DB9 PORTA.1
#DEFINE GLCD_DB10 PORTA.2
#DEFINE GLCD_DB11 PORTA.3
#DEFINE GLCD_DB12 PORTA.4
#DEFINE GLCD_DB13 PORTA.5
#DEFINE GLCD_DB14 PORTA.6
#DEFINE GLCD_DB15 PORTA.7
'GLCD font control
#DEFINE GLCD_EXTENDEDFONTSET1
'Define ports for ADS7843
#define ADS7843_DOUT PORTE.5 ' Arduino Mega D3
#define ADS7843_IRQ PORTE.4 ' Arduino Mega D2
#define ADS7843_CS PORTE.3 ' Arduino Mega D5
#define ADS7843_CLK PORTH.3 ' Arduino Mega D6
#define ADS7843_DIN PORTG.5 ' Arduino Mega D4
#define ADS7843_BUSY PORTH.4 ' Arduino Mega D7
Wait 100 ms
num=0
Do Forever
'Library function
if ADS7843_IRQ=0 then
num++
GLCDPrint 10, 15, str(num),SSD1289_YELLOW, 2
'Libary sub routine - returns two variables
ADS7843_GetXY ( TP_X , TP_Y )
if TP_X>=100 then GLCDPrint 100, 50, Str(TP_X),SSD1289_YELLOW, 2
if TP_X>=10 and TP_X<100 then GLCDPrint 100, 50, Str(TP_X)+" ",SSD1289_YELLOW, 2
if TP_X<10 then GLCDPrint 100, 50, Str(TP_X)+" ",SSD1289_YELLOW, 2
if TP_Y>=100 then GLCDPrint 100, 70, Str(TP_Y),SSD1289_YELLOW, 2
if TP_Y>=10 and TP_Y<100 then GLCDPrint 100, 70, Str(TP_Y)+" ", SSD1289_YELLOW, 2
if TP_Y<10 then GLCDPrint 100, 70, Str(TP_Y)+" ",SSD1289_YELLOW, 2
'Set the pixel to yellow using the GLCD PSET sub routine
Pset TP_X, TP_Y, SSD1289_YELLOW
end if
Wait 1 ms
Loop