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HTEB1
User manual
Issue 0.2 Page 41 07/2002
3.4 A/D + PWM
This sample shows the usage of the A/D converter. We sample the voltage
of P1/P2, filter it and show the result on the LCD. On D/A-Con you will see
a reversed voltage at P2 – built with a RC-filter from TOW (P76).
/*------------------------------------------------------------------
** AD_PWM Demo shows some funcions of the A/D converter
** and the use of PWM (= inverse output from P2) at D/A-Con
**-----------------------------------------------------------------*/
#include "mydefs.h" // with further includes!
#include "stdlib.h" // for abs()
void wait(u16 wastetime) // local LCD port delay
{
while(wastetime--);
}
/*
LCD-Port / Bits on TinyEvalBoard
RS = P75, R/W = P74, EN = P20, DATA = P5
*/
// some defines for easy access
#define CLEAR_LCD_RS (PDR7 &= ~0x20)
#define SET_LCD_RS (PDR7 |= 0x20)
#define CLEAR_LCD_RW (PDR7 &= ~0x10)
#define SET_LCD_RW (PDR7 |= 0x10)
#define CLEAR_LCD_EN (PDR2 &= ~0x01)
#define SET_LCD_EN (PDR2 |= 0x01)
#define LCD_DATA_PORT (PDR5)
#define LCD_DATA_CTRL (PCR5)
#define LCD_OUT 0xff
#define LCD_IN 0x00
#define LCD_WAIT {wait(100);}
void LCDWriteCmd(u8 cmd) // write cmd to LCD port
{
CLEAR_LCD_RS;
CLEAR_LCD_RW;
SET_LCD_EN;
LCD_DATA_PORT = cmd;
LCD_WAIT;
CLEAR_LCD_EN;
LCD_WAIT;
}
void LCDWriteData(u8 data) // write data to LCD port
{
SET_LCD_RS;
CLEAR_LCD_RW;
SET_LCD_EN;
LCD_DATA_PORT = data;
LCD_WAIT;
CLEAR_LCD_EN;
LCD_WAIT;
}
u8 LCDReadStatus(void) // get the LCD status register
{
u8 status;
CLEAR_LCD_RS;
SET_LCD_RW;