/** Initialize a decoder channel to process telemetry for sid from the
* specified tracking channel.
*
* \param tracking_channel Tracking channel to use.
* \param sid Signal to be decoded.
*
* \return true if a decoder channel was initialized, false otherwise.
*/
bool decoder_channel_init(u8 tracking_channel, gnss_signal_t sid)
{
decoder_channel_t *d = decoder_channel_get(tracking_channel);
if (decoder_channel_state_get(d) != DECODER_CHANNEL_STATE_DISABLED)
return false;
const decoder_interface_t *interface = decoder_interface_get(sid);
decoder_t *decoder;
if (!available_decoder_get(interface, &decoder))
return false;
/* Set up channel */
d->info.tracking_channel = tracking_channel;
d->info.sid = sid;
d->decoder = decoder;
/* Empty the nav bit FIFO */
s8 soft_bit;
while (tracking_channel_nav_bit_get(d->info.tracking_channel, &soft_bit)) {
;
}
interface_function(d, interface->init);
event(d, EVENT_ENABLE);
return true;
}
static void decoder_gps_l1ca_process(const decoder_channel_info_t *channel_info,
decoder_data_t *decoder_data)
{
gps_l1ca_decoder_data_t *data = decoder_data;
/* Process incoming nav bits */
s8 soft_bit;
while (tracking_channel_nav_bit_get(channel_info->tracking_channel,
&soft_bit)) {
/* Update TOW */
bool bit_val = soft_bit >= 0;
s32 TOW_ms = nav_msg_update(&data->nav_msg, bit_val);
s8 bit_polarity = data->nav_msg.bit_polarity;
if ((TOW_ms >= 0) && (bit_polarity != BIT_POLARITY_UNKNOWN)) {
if (!tracking_channel_time_sync(channel_info->tracking_channel, TOW_ms,
bit_polarity)) {
log_warn_sid(channel_info->sid, "TOW set failed");
}
}
}
/* Check if there is a new nav msg subframe to process. */
if (!subframe_ready(&data->nav_msg))
return;
/* Decode ephemeris to temporary struct */
ephemeris_t e = {.sid = channel_info->sid};
s8 ret = process_subframe(&data->nav_msg, &e);;
if (ret <= 0)
return;
/* Decoded a new ephemeris. */
ephemeris_new(&e);
ephemeris_t *eph = ephemeris_get(channel_info->sid);
if (!eph->valid) {
log_info_sid(channel_info->sid, "ephemeris is invalid");
}
}
