From 3540ef3006efd5d6c84f0fb40c258d9ea11b09bf Mon Sep 17 00:00:00 2001
From: sh123 <sh123@users.noreply.github.com>
Date: Wed, 15 Mar 2023 08:26:07 +0200
Subject: [PATCH] Allow to specify preamble length and select modem type from
 platformio ini

---
 include/config.h         |  3 ++-
 include/loraprs_config.h |  1 +
 platformio.ini           | 27 ++++++++++++++++++++-------
 src/loraprs_service.cpp  |  1 +
 src/main.cpp             |  1 +
 5 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/config.h b/include/config.h
index 3c5810f..78e4935 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2,7 +2,7 @@
 #define CONFIG_H
 
 // Uncomment for SX126X module usage
-#define USE_SX126X
+// #define USE_SX126X
 
 // Check your module name at https://github.com/jgromes/RadioLib/wiki/Modules
 #ifdef USE_SX126X
@@ -69,6 +69,7 @@
 #define CFG_LORA_EXPLICIT     true        // header mode, true - explicit, false - implicit
 #define CFG_LORA_SYNC         0x12        // sync word (0x12 - private used by other trackers, 0x34 - public used by LoRaWAN)
 #define CFG_LORA_PWR          20          // output power in dBm
+#define CFG_LORA_PREAMBLE     8           // preamble length from 6 to 65535
 
 // WiFi client and AP options
 #define CFG_WIFI_ENABLE_AP    false       // run as wifi access point (for CFG_KISS_TCP_IP mode)
diff --git a/include/loraprs_config.h b/include/loraprs_config.h
index b8f67b4..7d9ea50 100644
--- a/include/loraprs_config.h
+++ b/include/loraprs_config.h
@@ -21,6 +21,7 @@ struct Config
   int LoraSync;         // lora sync word/packet id, 0x34
   int LoraCrc;          // lora crc mode, 0 - disabled, 1 - 1 byte, 2 - 2 bytes
   bool LoraExplicit;    // lora header mode, true - explicit, false - implicit
+  int LoraPreamble;     // lora preamble length from 6 to 65535
 
   // lora hardware pinouts and isr
   byte LoraPinSs;       // lora ss pin
diff --git a/platformio.ini b/platformio.ini
index a4c0cd1..087dcb6 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -1,6 +1,6 @@
 [platformio]
 description = ESP32 LoRA APRS modem
-default_envs = esp32dev
+default_envs = esp32dev_sx126x_modem
 
 [env]
 platform = espressif32 @ 5.2.0
@@ -19,18 +19,31 @@ check_flags =
   cppcheck: --suppress=*:*.pio\* --inline-suppr -DCPPCHECK
 check_skip_packages = yes
 
-[env:esp32dev]
+[env:esp32dev_sx126x_modem]
 board = esp32dev
 build_flags =
-  '-D CFG_IS_CLIENT_MODE=true'
+  -D CFG_IS_CLIENT_MODE=true
+  -D USE_SX126X
 
-[env:esp32dev_igate]
+[env:esp32dev_sx126x_igate]
 board = esp32dev
 board_build.f_cpu = 240000000L
 build_flags =
-  '-D CFG_IS_CLIENT_MODE=false'
+  -D CFG_IS_CLIENT_MODE=false
+  -D USE_SX126X
 
-[env:ttgo-lora32-v1]
+[env:esp32dev_sx127x_modem]
+board = esp32dev
+build_flags =
+  -D CFG_IS_CLIENT_MODE=true
+
+[env:esp32dev_sx127x_igate]
+board = esp32dev
+board_build.f_cpu = 240000000L
+build_flags =
+  -D CFG_IS_CLIENT_MODE=false
+
+[env:ttgo-lora32-v1_modem]
 board = ttgo-lora32-v1
 build_flags =
-  '-D CFG_IS_CLIENT_MODE=true'
+  -D CFG_IS_CLIENT_MODE=true
diff --git a/src/loraprs_service.cpp b/src/loraprs_service.cpp
index 5d49593..b673fce 100644
--- a/src/loraprs_service.cpp
+++ b/src/loraprs_service.cpp
@@ -239,6 +239,7 @@ void Service::setupRig(long loraFreq, long bw, int sf, int cr, int pwr, int sync
     LOG_ERROR("Radio start error:", state);
   }
   rig_->setCRC(crcBytes);
+  rig_->setPreambleLength(config_.LoraPreamble);
 #ifdef USE_SX126X
     #pragma message("Using SX126X")
     LOG_INFO("Using SX126X module");
diff --git a/src/main.cpp b/src/main.cpp
index 17fafa6..8c6b049 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -41,6 +41,7 @@ void initializeConfig(LoraPrs::Config &cfg) {
   cfg.LoraCrc = CFG_LORA_CRC; // set to 0 to disable
   cfg.LoraExplicit = CFG_LORA_EXPLICIT;
   cfg.LoraPower = CFG_LORA_PWR;
+  cfg.LoraPreamble = CFG_LORA_PREAMBLE;
 
   // lora pinouts
   cfg.LoraPinSs = CFG_LORA_PIN_SS;