/* Compile with PK2CC5X Tool chain
https://github.com/willsandy/Fritzing-PK2-Cc5x */
/* hello_blink.c PICkit 2 breadboard LED + bitbanging com */
/* Program for testing components on breadboard */
/* Blink with LED, serial menu LED on/off blink +/- Sw status */
/* B Knudsen Cc5x C-compiler - not ANSI-C */
#include <16F690.h>
#include <int16Cxx.h>
#pragma config |= 0x00D4
/* FUNCTION PROTOTYPES */
void delay10( char );
void init_serial( void );
void putchar( char);
void printf(const char *string, char variable);
/* GLOBAL VARIABLES */
bit receiver_flag; /* Signal-flag used by interrupt routine */
char receiver_byte; /* Transfer Byte used by interrupt routine */
/* INTERRUPT ROUTINE */
/* Interrupt routine - receiving chars at need */
#pragma origin 4
interrupt int_server( void ) /* the place for the interrupt routine */
{
int_save_registers
/* New interrupts are automaticaly disabled */
/* "Interrupt on change" at pin RA1 from PK2 UART-tool */
if( PORTA.1 == 0 ) /* Interpret this as the startbit */
{ /* Receive one full character */
char bitCount, ti;
/* delay 1,5 bit 156 usec at 4 MHz */
/* 5+28*5-1+1+2+9=156 without optimization */
ti = 28; do ; while( --ti > 0); nop(); nop2();
for( bitCount = 8; bitCount > 0 ; bitCount--)
{
Carry = PORTA.1;
receiver_byte = rr( receiver_byte); /* rotate carry */
/* delay one bit 104 usec at 4 MHz */
/* 5+18*5-1+1+9=104 without optimization */
ti = 18; do ; while( --ti > 0); nop();
}
receiver_flag = 1; /* A full character is now received */
}
RABIF = 0; /* Reset the RABIF-flag before leaving */
int_restore_registers
/* New interrupts are now enabled */
}
/* MAIN PROGRAM */
void main( void)
{
/* Initialisations */
TRISC.0 = 0; /* PORTC pin 0 output to LED */
TRISC.7 = 1; /* PORTC pin 7 input from Button */
ANSELH.1 = 0; /* PORTC pin 7 not analog */
init_serial();
char speed = 100;
char period;
char choice;
bit blink=1;
receiver_flag=0;
IOCA.1 = 1; /* PORTA.1 interrupt on change */
RABIE =1; /* interrupt on change */
GIE = 1; /* interrupt enable */
/* Main loop */
while(1)
{
if( receiver_flag ) /* Character received? */
{
choice = receiver_byte;
receiver_flag = 0; /* Character now taken */
/* menu alternatives */
switch (choice)
{
case 'l':
case 'L':
printf("\r\n%c LED ON\r\n", choice);
PORTC.0 = 1; /* PORTC pin 0 "1" */
blink=0;
break;
case 'o':
case 'O':
printf("\r\n%c LED OFF\r\n", choice);
PORTC.0 = 0; /* PORTC pin 0 "0" */
blink=0;
break;
case 'b':
case 'B':
blink=1;
printf("\r\n%c LED BLINK\r\n", choice);
break;
case 'S':
case 's':
if(!PORTC.7) printf("\r\n%c Switch is ON/pressed\r\n", choice);
else printf("\r\n%c Switch is OFF/unpressed\r\n", choice);
break;
case '-':
if(period > 20) period -=10;
else period = 10;
printf("\r\n%c ", choice);
printf("Dec delay %u\r\n", period);
blink = 1;
break;
case '+':
if(period < 240) period +=10;
else period = 250;
printf("\r\n%c ", choice);
printf("Inc delay %u\r\n", period);
blink = 1;
break;
default:
printf("\r\n%c (L)ed On, led (O)ff, led (B)link, ",choice);
printf("(S)witch, delay (+),(-)\r\n",0);
}
}
/* Button action fast blink */
if(PORTC.7) speed = period; else speed = 10;
/* blink the led with different period */
if( blink )
{
delay10(speed);
PORTC.0 = 1; /* PORTC pin 0 "1" */
delay10(speed);
PORTC.0 = 0; /* PORTC pin 0 "0" */
}
}
}
/* *********************************** */
/* FUNCTIONS */
/* *********************************** */
void delay10( char n)
/*
Delays a multiple of 10 milliseconds using the TMR0 timer
Clock : 4 MHz => period T = 0.25 microseconds
1 IS = 1 Instruction Cycle = 1 microsecond
error: 0.16 percent
*/
{
char i;
OPTION = 7;
do {
i = TMR0 + 39; /* 256 microsec * 39 = 10 ms */
while ( i != TMR0)
;
} while ( --n > 0);
}
void init_serial( void ) /* initialise PIC16F690 bitbang serialcom */
{
ANSEL.0 = 0; /* No AD on RA0 */
ANSEL.1 = 0; /* No AD on RA1 */
PORTA.0 = 1; /* marking line */
TRISA.0 = 0; /* output to PK2 UART-tool */
TRISA.1 = 1; /* input from PK2 UART-tool */
return;
}
void putchar( char ch ) /* sends one char */
{
char bitCount, ti;
PORTA.0 = 0; /* set startbit */
for ( bitCount = 10; bitCount > 0 ; bitCount-- )
{
/* delay one bit 104 usec at 4 MHz */
/* 5+18*5-1+1+9=104 without optimization */
ti = 18; do ; while( --ti > 0); nop();
Carry = 1; /* stopbit */
ch = rr( ch ); /* Rotate Right through Carry */
PORTA.0 = Carry;
}
return;
}
void printf(const char *string, char variable) // printf look-alike
{
char i, k, m, a, b;
for(i = 0 ; ; i++)
{
k = string[i];
if( k == '\0') break; // at end of string
if( k == '%') // insert variable in string
{
i++;
k = string[i];
switch(k)
{
case 'd': // %d signed 8bit
if( variable.7 ==1) putchar('-');
else putchar(' ');
if( variable > 127) variable = -variable; // no break!
case 'u': // %u unsigned 8bit
a = variable/100;
putchar('0'+a); // print 100's
b = variable%100;
a = b/10;
putchar('0'+a); // print 10's
a = b%10;
putchar('0'+a); // print 1's
break;
case 'x': // %x HEX 8 bit
static const char Hex_table[16] = "0123456789ABCDEF" ;
a = swap(variable);
a = a & 0b0000.1111;
b = Hex_table[a];
putchar(b);
a = variable & 0b0000.1111;
b = Hex_table[a];
putchar(b);
break;
case 'b': // %b BINARY 8bit
for( m = 0 ; m < 8 ; m++ )
{
if (variable.7 == 1) putchar('1');
else putchar('0');
variable = rl(variable);
}
break;
case 'c': // %c 'char'
putchar(variable);
break;
case '%':
putchar('%');
break;
default: // not implemented
putchar('!');
}
}
else putchar(k);
}
}
/* *********************************** */
/* HARDWARE */
/* *********************************** */
/*
Serial communication with PK2 UART-tool
or used with TTL to USB Serial Converter
_____________ _____________
| \/ |
+5V---|Vdd 16F690 Vss|---Gnd
|RA5 RA0/AN0/(PGD)|bbTx->- PK2 UART-tool
|RA4/AN3 RA1/(PGC)|bbRx-<- PK2 UART-tool
|RA3/!MCLR/(Vpp) RA2/AN2/INT|
|RC5/CCP RC0|->-LED0
|RC4 RC1|
|RC3/AN7 RC2|
PullUp |RC6/AN8 AN10/RB4|
Butt_n->-|RC7/AN9 RB5/Rx|
|RB7/Tx RB6|
|____________________________|
UART RB7, RB6 not used by this program
TTL to USB Serial Converter if used with Frizing serial monitor:
FTDI TTL_232R-5V
unconnected --- 6 RTS# green
bbTx->- 1k resistor ->- 5 rxd yellow TTL_232R-5V
bbRx-<- 1k resistor -<- 4 txd orange TTL_232R-5V
unconnected --- 3 VCC red
unconnected --- 2 CTS# brown
Gnd --- 1 GND black
*/