Skip to content

Commit

Permalink
OpenLRS: work to improve reliability
Browse files Browse the repository at this point in the history 
This changes how the timing to get RSSI measurement is done
and improves the reliability of packet reception.
  • Loading branch information
@peabody124
peabody124 committed Nov 17, 2015
1 parent f069ece commit cf698ac
Showing 1 changed file with 39 additions and 19 deletions.
58 changes: 39 additions & 19 deletions flight/PiOS/Common/pios_openlrs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -101,6 +101,8 @@ static const uint8_t OUT_FF[64] = {

const uint8_t default_hop_list[] = {DEFAULT_HOPLIST};

const uint32_t packet_advance_time_us = 1500;

const struct rfm22_modem_regs bind_params =
{ 9600, 0x05, 0x40, 0x0a, 0xa1, 0x20, 0x4e, 0xa5, 0x00, 0x20, 0x24, 0x4e, 0xa5, 0x2c, 0x23, 0x30 };

Expand Down Expand Up @@ -794,10 +796,14 @@ static void pios_openlrs_rx_loop(struct pios_openlrs_dev *openlrs_dev)
timeUs = micros();
timeMs = millis();

DEBUG_PRINTF(2,"Time: %d\r\n", timeUs);

uint8_t *tx_buf = openlrs_dev->tx_buf; // convenient variable

if (openlrs_dev->rf_mode == Received) {

DEBUG_PRINTF(2,"Packet Received. Dt=%d\r\n", timeUs-openlrs_dev->lastPacketTimeUs);

// Read the packet from RFM22b
rfm22_claimBus(openlrs_dev);
rfm22_assertCs(openlrs_dev);
Expand Down Expand Up @@ -919,20 +925,8 @@ static void pios_openlrs_rx_loop(struct pios_openlrs_dev *openlrs_dev)
openlrs_dev->willhop = 1;
}

// sample RSSI when packet is in the 'air'
if ((openlrs_dev->numberOfLostPackets < 2) && (openlrs_dev->lastRSSITimeUs != openlrs_dev->lastPacketTimeUs) &&
(timeUs - openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) - 1500)) {

//DEBUG_PRINTF(3,"pios_openlrs_rx_loop -- measure RSSI\r\n");

openlrs_dev->lastRSSITimeUs = openlrs_dev->lastPacketTimeUs;
openlrs_status.LastRSSI = rfmGetRSSI(openlrs_dev); // Read the RSSI value

DEBUG_PRINTF(2,"RSSI: %d\r\n", openlrs_status.LastRSSI);
}

if (openlrs_dev->link_acquired) {
if ((openlrs_dev->numberOfLostPackets < openlrs_dev->hopcount) && ((timeUs - openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) + 1000))) {
if ((openlrs_dev->numberOfLostPackets < openlrs_dev->hopcount) && (PIOS_DELAY_GetuSSince(openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) + 1000))) {
DEBUG_PRINTF(2,"Lost packet: %d\r\n", openlrs_dev->numberOfLostPackets);
// we lost packet, hop to next channel
openlrs_status.LinkQuality <<= 1;
Expand All @@ -946,7 +940,8 @@ static void pios_openlrs_rx_loop(struct pios_openlrs_dev *openlrs_dev)
openlrs_dev->willhop = 1;
//updateLBeep(true);
// TODO: set_RSSI_output();
} else if ((openlrs_dev->numberOfLostPackets >= openlrs_dev->hopcount) && ((timeUs - openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) * openlrs_dev->hopcount))) {
} else if ((openlrs_dev->numberOfLostPackets >= openlrs_dev->hopcount) && (PIOS_DELAY_GetuSSince(openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) * openlrs_dev->hopcount))) {
DEBUG_PRINTF(2,"Trying to resync\r\n");
// hop slowly to allow resync with TX
openlrs_status.LinkQuality = 0;
openlrs_dev->willhop = 1;
Expand Down Expand Up @@ -988,8 +983,8 @@ static void pios_openlrs_rx_loop(struct pios_openlrs_dev *openlrs_dev)

} else {
// Waiting for first packet, hop slowly
if ((timeUs - openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) * openlrs_dev->hopcount)) {
//DEBUG_PRINTF(3,"pios_openlrs_rx_loop - slow hop\r\n");
if (PIOS_DELAY_GetuSSince(openlrs_dev->lastPacketTimeUs) > (getInterval(&openlrs_dev->bind_data) * openlrs_dev->hopcount)) {
DEBUG_PRINTF(3,"Trying to get first packet\r\n");
openlrs_dev->lastPacketTimeUs = timeUs;
openlrs_dev->willhop = 1;
}
Expand Down Expand Up @@ -1193,14 +1188,39 @@ static void pios_openlrs_task(void *parameters)
PIOS_WDG_UpdateFlag(PIOS_WDG_RFM22B);
#endif /* PIOS_WDG_RFM22B */

uint32_t time_till_measure_rssi_us = (getInterval(&openlrs_dev->bind_data) - 1500) + openlrs_dev->lastPacketTimeUs - micros();
// Determine
uint32_t time_since_packet_us = PIOS_DELAY_GetuSSince(openlrs_dev->lastPacketTimeUs); // How long we have been thinking since receiving packet
uint32_t time_till_measure_rssi_us = (getInterval(&openlrs_dev->bind_data) - packet_advance_time_us) - time_since_packet_us;
uint32_t delay = time_till_measure_rssi_us / 1000;
uint32_t max_delay = getInterval(&openlrs_dev->bind_data) / 2000;

// Maximum delay based on packet time, ISR should fire before this
const uint32_t max_delay = getInterval(&openlrs_dev->bind_data) / 1000;
if (delay > max_delay) delay = max_delay;
PIOS_Semaphore_Take(openlrs_dev->sema_isr, delay);

// If we already got RSSI for this packet no need to schedule early
if (openlrs_dev->lastRSSITimeUs == openlrs_dev->lastPacketTimeUs) {
delay = max_delay;
}

if (PIOS_Semaphore_Take(openlrs_dev->sema_isr, delay) == FALSE) {
DEBUG_PRINTF(3, "ISR Timeout %d %d %d %d\r\n", delay, getInterval(&openlrs_dev->bind_data), time_till_measure_rssi_us, time_since_packet_us);

// sample RSSI when packet is in the 'air'
if ((openlrs_dev->numberOfLostPackets < 2) && (openlrs_dev->lastRSSITimeUs != openlrs_dev->lastPacketTimeUs)) {

openlrs_dev->lastRSSITimeUs = openlrs_dev->lastPacketTimeUs;
openlrs_status.LastRSSI = rfmGetRSSI(openlrs_dev); // Read the RSSI value

DEBUG_PRINTF(2,"RSSI: %d\r\n", openlrs_status.LastRSSI);
}
} else {
DEBUG_PRINTF(3, "ISR %d %d %d %d\r\n", delay, getInterval(&openlrs_dev->bind_data), time_till_measure_rssi_us, time_since_packet_us);
}

// Process incoming radio data.
pios_openlrs_rx_loop(openlrs_dev);

DEBUG_PRINTF(3, "Processing time %d\r\n", PIOS_DELAY_GetuSSince(openlrs_dev->lastPacketTimeUs));
}
}

Expand Down

0 comments on commit cf698ac

Please sign in to comment.