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Commit 218a38adb79c1546de32a3231987489f20bbf88c
Parents : 729a409
Author : Mark Qvist <mark@unsigned.io>
Date : 2025-01-09T00:01:49+01:00
Optimise packet handling for SX1280 fast data rates
Changes
4 files changed, 56 insertions(+), 5 deletions(-)
Diff
diff --git a/Boards.h b/Boards.h
index c292a21..6cf0e6b 100644
--- a/Boards.h
+++ b/Boards.h
@@ -445,7 +445,7 @@
const int pin_dio = 33;
const int pin_tcxo_enable = -1;
#elif MODEM == SX1280
- #define CONFIG_QUEUE_SIZE 40960
+ #define CONFIG_QUEUE_SIZE 6144
#define DIO2_AS_RF_SWITCH false
#define HAS_BUSY true
#define HAS_TCXO true
diff --git a/Config.h b/Config.h
index 80865d6..4649895 100644
--- a/Config.h
+++ b/Config.h
@@ -71,6 +71,9 @@
#define PHY_CRC_LORA_BITS 16
#define LORA_PREAMBLE_SYMBOLS_MIN 18
#define LORA_PREAMBLE_TARGET_MS 24
+ #define LORA_PREAMBLE_FAST_DELTA 18
+ #define LORA_FAST_THRESHOLD_BPS 30E3
+ #define LORA_LIMIT_THRESHOLD_BPS 60E3
long lora_preamble_symbols = LORA_PREAMBLE_SYMBOLS_MIN;
long lora_preamble_time_ms = 0;
long lora_header_time_ms = 0;
@@ -78,12 +81,14 @@
float lora_symbol_rate = 0.0;
float lora_us_per_byte = 0.0;
bool lora_low_datarate = false;
+ bool lora_limit_rate = false;
// CSMA Parameters
#define CSMA_SIFS_MS 0
#define CSMA_POST_TX_YIELD_SLOTS 3
#define CSMA_SLOT_MAX_MS 100
#define CSMA_SLOT_MIN_MS 24
+ #define CSMA_SLOT_MIN_FAST_DELTA 18
#define CSMA_SLOT_SYMBOLS 12
#define CSMA_CW_BANDS 4
#define CSMA_CW_MIN 0
diff --git a/RNode_Firmware.ino b/RNode_Firmware.ino
index 880aed5..463ee55 100644
--- a/RNode_Firmware.ino
+++ b/RNode_Firmware.ino
@@ -553,6 +553,45 @@ void flush_queue(void) {
#endif
}
+void pop_queue() {
+ if (!queue_flushing) {
+ queue_flushing = true;
+ led_tx_on(); uint16_t processed = 0;
+
+ #if MCU_VARIANT == MCU_ESP32 || MCU_VARIANT == MCU_NRF52
+ if (!fifo16_isempty(&packet_starts)) {
+ #else
+ if (!fifo16_isempty_locked(&packet_starts)) {
+ #endif
+
+ uint16_t start = fifo16_pop(&packet_starts);
+ uint16_t length = fifo16_pop(&packet_lengths);
+ if (length >= MIN_L && length <= MTU) {
+ for (uint16_t i = 0; i < length; i++) {
+ uint16_t pos = (start+i)%CONFIG_QUEUE_SIZE;
+ tbuf[i] = packet_queue[pos];
+ }
+
+ transmit(length); processed++;
+ }
+ queue_height -= processed;
+ queued_bytes -= length;
+ }
+
+ lora_receive(); led_tx_off();
+ }
+
+ #if MCU_VARIANT == MCU_ESP32 || MCU_VARIANT == MCU_NRF52
+ update_airtime();
+ #endif
+
+ queue_flushing = false;
+
+ #if HAS_DISPLAY
+ display_tx = true;
+ #endif
+}
+
void add_airtime(uint16_t written) {
#if MCU_VARIANT == MCU_ESP32 || MCU_VARIANT == MCU_NRF52
float lora_symbols = 0;
@@ -1376,9 +1415,8 @@ void tx_queue_handler() {
cw_wait_passed += millis()-cw_wait_start; cw_wait_start = millis();
if (cw_wait_passed < cw_wait_target) { return; } // Contention window wait time has not yet passed, continue waiting
else { // Wait time has passed, flush the queue
- flush_queue();
+ if (!lora_limit_rate) { flush_queue(); } else { pop_queue(); }
cw_wait_passed = 0; csma_cw = -1; difs_wait_start = -1; }
-
}
}
}
diff --git a/Utilities.h b/Utilities.h
index 2dc102a..3b54629 100644
--- a/Utilities.h
+++ b/Utilities.h
@@ -1101,12 +1101,20 @@ void updateBitrate() {
lora_bitrate = (uint32_t)(lora_sf * ( (4.0/(float)lora_cr) / ((float)(pow(2, lora_sf))/((float)lora_bw/1000.0)) ) * 1000.0);
lora_us_per_byte = 1000000.0/((float)lora_bitrate/8.0);
+ bool fast_rate = lora_bitrate > LORA_FAST_THRESHOLD_BPS;
+ lora_limit_rate = lora_bitrate > LORA_LIMIT_THRESHOLD_BPS;
+
+ int csma_slot_min_ms = CSMA_SLOT_MIN_MS;
+ float lora_preamble_target_ms = LORA_PREAMBLE_TARGET_MS;
+ if (fast_rate) { csma_slot_min_ms -= CSMA_SLOT_MIN_FAST_DELTA;
+ lora_preamble_target_ms -= LORA_PREAMBLE_FAST_DELTA; }
+
csma_slot_ms = lora_symbol_time_ms*CSMA_SLOT_SYMBOLS;
if (csma_slot_ms > CSMA_SLOT_MAX_MS) { csma_slot_ms = CSMA_SLOT_MAX_MS; }
- if (csma_slot_ms < CSMA_SLOT_MIN_MS) { csma_slot_ms = CSMA_SLOT_MIN_MS; }
+ if (csma_slot_ms < CSMA_SLOT_MIN_MS) { csma_slot_ms = csma_slot_min_ms; }
difs_ms = CSMA_SIFS_MS + 2*csma_slot_ms;
- float target_preamble_symbols = LORA_PREAMBLE_TARGET_MS/lora_symbol_time_ms;
+ float target_preamble_symbols = lora_preamble_target_ms/lora_symbol_time_ms;
if (target_preamble_symbols < LORA_PREAMBLE_SYMBOLS_MIN) { target_preamble_symbols = LORA_PREAMBLE_SYMBOLS_MIN; }
else { target_preamble_symbols = (ceil)(target_preamble_symbols); }
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