static int __getc(void)
{
uint8_t bit;
uint8_t ch;
half_bit_delay();
if (rx_pin() != STARTBIT)
return -1; /* Glitch */
bit_delay();
for (bit = 0; bit < 8; bit++) {
ch = ch >> 1;
if (rx_pin())
ch |= 1 << 7;
bit_delay();
}
if (rx_pin() != STOPBIT)
return -2; /* Frame error */
return (int) ch;
}
void get_char(volatile unsigned char *pins, unsigned char pin, char *rxbyte) {
//
// read character into rxbyte on pins pin
// assumes line driver (inverts bits)
//
*rxbyte = 0;
while (pin_test(*pins,pin))
//
// wait for start bit
//
;
//
// delay to middle of first data bit
//
half_bit_delay();
bit_delay();
//
// unrolled loop to read data bits
//
if pin_test(*pins,pin)
*rxbyte |= (1 << 0);
else
