void nmea_process_character(char c) {
switch (c) {
case '$': /* a new sentence is starting */
sentence_started();
/* reset and enable checksum calculation */
checksum = 0;
checksum_state = CS_CALC;
break;
case ',':
token_finished();
break;
case '*': /* checksum is following */
token_finished();
checksum_state = CS_READ;
break;
case '\r':
/* \n is following soon, we ignore this */
break;
case '\n':
token_finished();
ATOMIC(ATOMIC_FORCEON) {
sentence_finished();
}
checksum_state = CS_UNKNOWN;
break;
default:
append_to_token(c);
}
if (checksum_state == CS_CALC && c != '$') {
add_to_checksum(c);
}
}
static void
add_buf_to_checksum(unsigned char *buf, int len) {
unsigned char *c;
int i;
for (i = 0, c = buf; i < len; i++, c++) {
add_to_checksum(*c);
}
}
int
casio_qv_send_byte(sdcInfo info, unsigned char c) {
add_to_checksum(c);
return(sdcSendByte(info, c));
}