User manual

84 l Robotics experiment with PIC microcontroller
Listing A11-1 : The C program for Robo-PICA to controlled with ER-4 remote
control (continue)
#include <motor.h>
char *text = "ER-4 Remote"; // Define message
unsigned char ir_cmd=0; // Keep Command button from ER-4 Remote
//------------------ Interrupt service routine INT -----------------//
void interrupt()
{
unsigned char i; // Keep counter
if(INTCON.INTF) // Check interrupt flag RB0 (Falling edge)
{
Delay_us(416); // Delay 1/2 of 1 bit timing(baudrate 1200 bps)
for(i=0;i<8;i++) // Loop for 8 time for keep data from ER-4 Remote
{
Delay_us(833); // Delay of 1 bit timing(baudrate 1200 bps)
ir_cmd = ir_cmd>>1; // Shitt bit 1 time
if((PORTB & 0x01)==1) // Get logic @ RB0 = '1'?
ir_cmd = ir_cmd | 0x80; // Inset bit data is '1'
}
Delay_us(833); // Delay of 1 bit timing(baudrate 1200 bps)
INTCON.INTF =0; // Clear interrupt flag
}
}
//------------------ Function for get character from Remote ---------//
unsigned char get_remote()
{
unsigned char _key=ir_cmd; // Get character to buffer
ir_cmd=0; // Clear old data
return(_key); // Return character from Remote
}
//------------------ Main Program ----------------------------------//
void main()
{
unsigned char key; // Save Remote Key Press
ANSELH.F4=0; // RB0 ==> Digital IO
OPTION_REG.INTEDG = 0; // INT falling edge
INTCON.INTE =1; // Enable INT/PB0
INTCON.GIE =1; // Enable Global interrupt
Lcd_Init(&PORTD); // Initialize LCD connected to PORTD
Lcd_Cmd(Lcd_CLEAR); // Clear display
Lcd_Cmd(Lcd_CURSOR_OFF); // Turn cursor off
Lcd_Out(1, 1, text); // Print text to LCD, 2nd row, 1st column
Sound_Init(&PORTC,0);
while(1) // Infinite loop
{
if (ir_cmd==0)
{
Motor_Stop();
}
else
{
key = get_remote(); // Get Remote
if(key=='a' || key=='A') // Button A press?