int
_serial_putchar(int c)
{
static unsigned int txmask;
static unsigned int bitcycles;
static unsigned int cached_baud;
if (cached_baud != _baud) {
cached_baud = _baud;
bitcycles = _clkfreq / cached_baud;
txmask = (1UL << _txpin);
}
if (c == '\n') {
_serial_tx('\r', txmask, bitcycles);
}
return _serial_tx(c, txmask, bitcycles);
}
static void _serial_tx_char(char c)
{
uint8_t buffer[10];
uint8_t i = 0;
buffer[i++] = 0; // START
for (int idx = 0; idx < 8; ++idx)
buffer[i++] = (((uint8_t)(c) & ((uint8_t)1<<((idx)))) ? 0x01 : 0x00); // Endianness: 7-
buffer[i++] = 1; // STOP
_serial_tx(buffer);
}