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Commit 08651f92f78de9990f7036fbcb42a3294d5dfe9d


Parents : e40532e
Author : Mark Qvist <mark@unsigned.io>
Date : 2025-01-07T15:14:44+01:00

Reworked SX1262 LoRa carrier detection

Changes

7 files changed, 70 insertions(+), 65 deletions(-)

M Boards.h +6
M Config.h +4
M Makefile +4 -4
M Utilities.h +3 -1
M sx126x.cpp +32 -15
M sx126x.h +1 -1

Diff

diff --git a/Boards.h b/Boards.h
index c292a21..aa1a4f1 100644
--- a/Boards.h
+++ b/Boards.h
@@ -13,6 +13,12 @@
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
+// TODO: Remove debug setup
+#define PIN_PREAMBLE 7
+#define PIN_HEADER 6
+#define PIN_DCD 5
+#define PIN_TXSIG 4
+
#include "Modem.h"
#ifndef BOARDS_H

diff --git a/Config.h b/Config.h
index b4ac7e7..f6569b4 100644
--- a/Config.h
+++ b/Config.h
@@ -70,6 +70,8 @@
const int lora_rx_turnaround_ms = 66;
const int lora_post_tx_yield_slots = 6;
uint32_t post_tx_yield_timeout = 0;
+ #define PHY_HEADER_LORA_SYMBOLS 20
+ #define PHY_CRC_LORA_BITS 16
#define LORA_PREAMBLE_SYMBOLS_MIN 18
#define LORA_PREAMBLE_TARGET_MS 15
#define LORA_CAD_SYMBOLS 3
@@ -78,6 +80,8 @@
#define CSMA_SLOT_MIN_MS 24
long lora_preamble_symbols = 12;
+ long lora_preamble_time_ms = 0;
+ long lora_header_time_ms = 0;
float lora_symbol_time_ms = 0.0;
float lora_symbol_rate = 0.0;
float lora_us_per_byte = 0.0;

diff --git a/Makefile b/Makefile
index d3f357c..8f3364c 100644
--- a/Makefile
+++ b/Makefile
@@ -156,8 +156,8 @@ upload-tbeam_sx1262:
arduino-cli upload -p /dev/ttyACM0 --fqbn esp32:esp32:t-beam
@sleep 1
rnodeconf /dev/ttyACM0 --firmware-hash $$(./partition_hashes ./build/esp32.esp32.t-beam/RNode_Firmware.ino.bin)
- @sleep 3
- python ./Release/esptool/esptool.py --chip esp32 --port /dev/ttyACM0 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size 4MB 0x210000 ./Release/console_image.bin
+ #@sleep 3
+ #python ./Release/esptool/esptool.py --chip esp32 --port /dev/ttyACM0 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size 4MB 0x210000 ./Release/console_image.bin
upload-lora32_v10:
arduino-cli upload -p /dev/ttyUSB0 --fqbn esp32:esp32:ttgo-lora32
@@ -188,9 +188,9 @@ upload-heltec32_v2:
python ./Release/esptool/esptool.py --chip esp32 --port /dev/ttyUSB1 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size 4MB 0x210000 ./Release/console_image.bin
upload-heltec32_v3:
- arduino-cli upload -p /dev/ttyUSB1 --fqbn esp32:esp32:heltec_wifi_lora_32_V3
+ arduino-cli upload -p /dev/ttyUSB2 --fqbn esp32:esp32:heltec_wifi_lora_32_V3
@sleep 1
- rnodeconf /dev/ttyUSB1 --firmware-hash $$(./partition_hashes ./build/esp32.esp32.heltec_wifi_lora_32_V3/RNode_Firmware.ino.bin)
+ rnodeconf /dev/ttyUSB2 --firmware-hash $$(./partition_hashes ./build/esp32.esp32.heltec_wifi_lora_32_V3/RNode_Firmware.ino.bin)
#@sleep 3
#python ./Release/esptool/esptool.py --chip esp32-s3 --port /dev/ttyUSB0 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size 4MB 0x210000 ./Release/console_image.bin

diff --git a/RNode_Firmware.ino b/RNode_Firmware.ino
index f8d5b35..f38162b 100644
--- a/RNode_Firmware.ino
+++ b/RNode_Firmware.ino
@@ -59,6 +59,13 @@ char sbuf[128];
#endif
void setup() {
+ // TODO: Remove debug setup
+ pinMode(PIN_PREAMBLE, OUTPUT);
+ pinMode(PIN_HEADER, OUTPUT);
+ pinMode(PIN_DCD, OUTPUT);
+ pinMode(PIN_TXSIG, OUTPUT);
+ ///////////////////////////
+
#if MCU_VARIANT == MCU_ESP32
boot_seq();
EEPROM.begin(EEPROM_SIZE);
@@ -516,6 +523,10 @@ bool queueFull() {
volatile bool queue_flushing = false;
void flushQueue(void) {
if (!queue_flushing) {
+
+ // TODO: Remove debug
+ digitalWrite(PIN_TXSIG, HIGH);
+
queue_flushing = true;
led_tx_on();
@@ -557,8 +568,6 @@ void flushQueue(void) {
#endif
}
-#define PHY_HEADER_LORA_SYMBOLS 20
-#define PHY_CRC_LORA_BITS 16
void add_airtime(uint16_t written) {
#if MCU_VARIANT == MCU_ESP32 || MCU_VARIANT == MCU_NRF52
float lora_symbols = 0;
@@ -1197,7 +1206,7 @@ void updateModemStatus() {
portENTER_CRITICAL();
#endif
- uint8_t status = LoRa->modemStatus();
+ bool carrier_detected = LoRa->dcd();
current_rssi = LoRa->currentRssi();
last_status_update = millis();
@@ -1207,47 +1216,13 @@ void updateModemStatus() {
portEXIT_CRITICAL();
#endif
- if ((status & SIG_DETECT) == SIG_DETECT) { stat_signal_detected = true; } else { stat_signal_detected = false; }
- if ((status & SIG_SYNCED) == SIG_SYNCED) { stat_signal_synced = true; } else { stat_signal_synced = false; }
- if ((status & RX_ONGOING) == RX_ONGOING) { stat_rx_ongoing = true; } else { stat_rx_ongoing = false; }
-
- // if (stat_signal_detected || stat_signal_synced || stat_rx_ongoing) {
- if (stat_signal_detected || stat_signal_synced) {
- if (stat_rx_ongoing) {
- if (dcd_count < dcd_threshold) {
- dcd_count++;
- } else {
- last_dcd = last_status_update;
- dcd_led = true;
- dcd = true;
- }
- }
- } else {
- #define DCD_LED_STEP_D 3
- if (dcd_count == 0) {
- dcd_led = false;
- } else if (dcd_count > DCD_LED_STEP_D) {
- dcd_count -= DCD_LED_STEP_D;
- } else {
- dcd_count = 0;
- }
-
- if (last_status_update > last_dcd+csma_slot_ms) {
- dcd = false;
- dcd_led = false;
- dcd_count = 0;
- }
- }
+ if (carrier_detected) { dcd = true; digitalWrite(PIN_DCD, HIGH); /* TODO: Remove debug */ }
+ else { dcd = false; digitalWrite(PIN_DCD, LOW); /* TODO: Remove debug */ }
- if (dcd_led) {
- led_rx_on();
- } else {
- if (airtime_lock) {
- led_indicate_airtime_lock();
- } else {
- led_rx_off();
- }
- }
+ dcd_led = dcd;
+ if (dcd_led) { led_rx_on(); }
+ else { if (airtime_lock) { led_indicate_airtime_lock(); }
+ else { led_rx_off(); } }
}
void checkModemStatus() {
@@ -1463,6 +1438,7 @@ void loop() {
if (!airtime_lock) {
if (queue_height > 0) {
#if MCU_VARIANT == MCU_ESP32 || MCU_VARIANT == MCU_NRF52
+
long check_time = millis();
if (check_time > post_tx_yield_timeout) {
if (dcd_waiting && (check_time >= dcd_wait_until)) { dcd_waiting = false; }
@@ -1486,7 +1462,7 @@ void loop() {
#else
if (!dcd_waiting) updateModemStatus();
- if (!dcd && !dcd_led) {
+ if (!dcd) {
if (dcd_waiting) delay(lora_rx_turnaround_ms);
updateModemStatus();

diff --git a/Utilities.h b/Utilities.h
index 5a981bd..32a1fc6 100644
--- a/Utilities.h
+++ b/Utilities.h
@@ -864,7 +864,7 @@ void kiss_indicate_phy_stats() {
uint16_t lst = (uint16_t)(lora_symbol_time_ms*1000);
uint16_t lsr = (uint16_t)(lora_symbol_rate);
uint16_t prs = (uint16_t)(lora_preamble_symbols);
- uint16_t prt = (uint16_t)((lora_preamble_symbols)*lora_symbol_time_ms);
+ uint16_t prt = (uint16_t)(lora_preamble_time_ms);
uint16_t cst = (uint16_t)(csma_slot_ms);
serial_write(FEND);
serial_write(CMD_STAT_PHYPRM);
@@ -1102,6 +1102,8 @@ void updateBitrate() {
lora_preamble_symbols = (long)target_preamble_symbols;
setPreamble();
+ lora_preamble_time_ms = (ceil)(lora_preamble_symbols * lora_symbol_time_ms);
+ lora_header_time_ms = (ceil)(PHY_HEADER_LORA_SYMBOLS * lora_symbol_time_ms);
} else {
lora_bitrate = 0;
}

diff --git a/sx126x.cpp b/sx126x.cpp
index 697d97d..a169f77 100644
--- a/sx126x.cpp
+++ b/sx126x.cpp
@@ -97,7 +97,7 @@ extern SPIClass SPI;
#define MAX_PKT_LENGTH 255
sx126x::sx126x() :
- _spiSettings(8E6, MSBFIRST, SPI_MODE0),
+ _spiSettings(16E6, MSBFIRST, SPI_MODE0),
_ss(LORA_DEFAULT_SS_PIN), _reset(LORA_DEFAULT_RESET_PIN), _dio0(LORA_DEFAULT_DIO0_PIN), _busy(LORA_DEFAULT_BUSY_PIN), _rxen(LORA_DEFAULT_RXEN_PIN),
_frequency(0),
_txp(0),
@@ -293,11 +293,11 @@ void sx126x::calibrate(void) {
void sx126x::calibrate_image(long frequency) {
uint8_t image_freq[2] = {0};
- if (frequency >= 430E6 && frequency <= 440E6) { image_freq[0] = 0x6B; image_freq[1] = 0x6F; }
+ if (frequency >= 430E6 && frequency <= 440E6) { image_freq[0] = 0x6B; image_freq[1] = 0x6F; }
else if (frequency >= 470E6 && frequency <= 510E6) { image_freq[0] = 0x75; image_freq[1] = 0x81; }
else if (frequency >= 779E6 && frequency <= 787E6) { image_freq[0] = 0xC1; image_freq[1] = 0xC5; }
else if (frequency >= 863E6 && frequency <= 870E6) { image_freq[0] = 0xD7; image_freq[1] = 0xDB; }
- else if (frequency >= 902E6 && frequency <= 928E6) { image_freq[0] = 0xE1; image_freq[1] = 0xE9; }
+ else if (frequency >= 902E6 && frequency <= 928E6) { image_freq[0] = 0xE1; image_freq[1] = 0xE9; } // TODO: Allow higher freq calibration
executeOpcode(OP_CALIBRATE_IMAGE_6X, image_freq, 2);
waitOnBusy();
}
@@ -372,6 +372,9 @@ int sx126x::endPacket() {
yield();
}
+ // TODO: Remove debug
+ digitalWrite(PIN_TXSIG, LOW);
+
if (!(millis() < w_timeout)) { timed_out = true; }
// Clear IRQs
@@ -382,27 +385,41 @@ int sx126x::endPacket() {
if (timed_out) { return 0; } else { return 1; }
}
-uint8_t sx126x::modemStatus() {
- // Imitate the register status from the sx1276 / 78
- uint8_t buf[2] = {0};
- executeOpcodeRead(OP_GET_IRQ_STATUS_6X, buf, 2);
- uint8_t clearbuf[2] = {0};
- uint8_t byte = 0x00;
+unsigned long preamble_detected_at = 0;
+unsigned long header_detected_at = 0;
+extern long lora_preamble_time_ms;
+extern long lora_header_time_ms;
+bool sx126x::dcd() {
+ bool carrier_detected = false;
+ uint8_t buf[2] = {0}; executeOpcodeRead(OP_GET_IRQ_STATUS_6X, buf, 2);
if ((buf[1] & IRQ_PREAMBLE_DET_MASK_6X) != 0) {
- byte = byte | 0x01 | 0x04;
- clearbuf[1] = IRQ_PREAMBLE_DET_MASK_6X; // Clear register after reading
+ carrier_detected = true;
+ if (preamble_detected_at == 0) preamble_detected_at = millis();
+ if (millis() - preamble_detected_at > lora_preamble_time_ms + lora_header_time_ms) {
+ preamble_detected_at = 0;
+ uint8_t clearbuf[2] = {0};
+ clearbuf[1] = IRQ_PREAMBLE_DET_MASK_6X;
+ executeOpcode(OP_CLEAR_IRQ_STATUS_6X, clearbuf, 2);
+ }
+ // TODO: Remove
+ digitalWrite(PIN_PREAMBLE, HIGH);
+ } else {
+ digitalWrite(PIN_PREAMBLE, LOW);
}
if ((buf[1] & IRQ_HEADER_DET_MASK_6X) != 0) {
- byte = byte | 0x02 | 0x04;
+ carrier_detected = true;
+ header_detected_at = millis();
+ // TODO: Remove
+ digitalWrite(PIN_HEADER, HIGH);
+ } else {
+ digitalWrite(PIN_HEADER, LOW);
}
- executeOpcode(OP_CLEAR_IRQ_STATUS_6X, clearbuf, 2);
- return byte;
+ return carrier_detected;
}
-
uint8_t sx126x::currentRssiRaw() {
uint8_t byte = 0;
executeOpcodeRead(OP_CURRENT_RSSI_6X, &byte, 1);

diff --git a/sx126x.h b/sx126x.h
index 1edf750..1703a8f 100644
--- a/sx126x.h
+++ b/sx126x.h
@@ -68,7 +68,7 @@ public:
void setCodingRate4(int denominator);
void setPreambleLength(long preamble_symbols);
void setSyncWord(uint16_t sw);
- uint8_t modemStatus();
+ bool dcd();
void enableCrc();
void disableCrc();
void enableTCXO();


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