From fc0ad84b4bcf6181081885dc483939152f064d3d Mon Sep 17 00:00:00 2001
From: sh123 <sh123@users.noreply.github.com>
Date: Wed, 26 May 2021 19:11:33 +0300
Subject: [PATCH] Add experimental external PTT control

---
 config.h            |  5 +++++
 esp32_loraprs.ino   |  6 ++++++
 kiss_processor.h    |  2 ++
 loraprs_config.h    |  6 ++++++
 loraprs_service.cpp | 28 ++++++++++++++++++++++++++--
 5 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/config.h b/config.h
index 9445f71..5580f4e 100644
--- a/config.h
+++ b/config.h
@@ -47,3 +47,8 @@
 #define CFG_IS_TO_RF          false
 #define CFG_BEACON            false
 #define CFG_KISS_EXTENSIONS   false
+
+#define CFG_PTT_ENABLE        false
+#define CFG_PTT_PIN           12
+#define CFG_PTT_TX_DELAY_MS   50
+#define CFG_PTT_TX_TAIL_MS    10
diff --git a/esp32_loraprs.ino b/esp32_loraprs.ino
index 7c5c289..0342868 100644
--- a/esp32_loraprs.ino
+++ b/esp32_loraprs.ino
@@ -64,6 +64,12 @@ void initializeConfig(LoraPrs::Config &cfg) {
   cfg.EnableRepeater = CFG_DIGIREPEAT; // digirepeat incoming packets
   cfg.EnableBeacon = CFG_BEACON;  // enable periodic AprsRawBeacon beacon to rf and aprsis if rf to aprsis is enabled
   cfg.EnableKissExtensions = CFG_KISS_EXTENSIONS; // radio control and signal reports
+
+  // external ptt control
+  cfg.PttEnable = CFG_PTT_ENABLE;
+  cfg.PttPin = CFG_PTT_PIN;
+  cfg.PttTxDelayMs = CFG_PTT_TX_DELAY_MS;
+  cfg.PttTxTailMs = CFG_PTT_TX_TAIL_MS;
 }
 
 LoraPrs::Service loraPrsService;
diff --git a/kiss_processor.h b/kiss_processor.h
index de99ff4..cb90619 100644
--- a/kiss_processor.h
+++ b/kiss_processor.h
@@ -31,8 +31,10 @@ protected:
 
   enum Cmd {
     Data = 0x00,
+    TxDelay = 0x01,
     P = 0x02,
     SlotTime = 0x03,
+    TxTail = 0x04,
     SetHardware = 0x06,
     SignalReport = 0x07,
     NoCmd = 0x80
diff --git a/loraprs_config.h b/loraprs_config.h
index d575011..bff3aba 100644
--- a/loraprs_config.h
+++ b/loraprs_config.h
@@ -54,6 +54,12 @@ struct Config
   bool EnableIsToRf;                    // true - enable APRS-IS to RF submission
   bool EnableRepeater;                  // true - digirepeat incoming packets based on WIDEn-n paths
   bool EnableBeacon;                    // true - send AprsRawBeacon to RF and APRS-IS if EnableRfToIs is true
+
+  // external ptt tx control
+  bool PttEnable;                       // true - enable external ptt control
+  int PttPin;                           // esp pin to set high on transmit
+  int PttTxDelayMs;                     // ptt tx delay
+  int PttTxTailMs;                      // ptt tx tail
 };
 
 } // LoraPrs
diff --git a/loraprs_service.cpp b/loraprs_service.cpp
index 268d7f3..123fa36 100644
--- a/loraprs_service.cpp
+++ b/loraprs_service.cpp
@@ -43,6 +43,11 @@ void Service::setup(const Config &conf)
   if (needsAprsis() && config_.EnablePersistentAprsConnection) {
     reconnectAprsis();
   }
+
+  if (config_.PttEnable) {
+    Serial.println("External PTT is enabled");
+    pinMode(config_.PttPin, OUTPUT);
+  }
 }
 
 void Service::setupWifi(const String &wifiName, const String &wifiKey)
@@ -357,7 +362,12 @@ void Service::processIncomingRawPacketAsServer(const byte *packet, int packetLen
 
 bool Service::onRigTxBegin()
 {
-  delay(CfgPollDelayMs);
+  if (config_.PttEnable) {
+    digitalWrite(config_.PttPin, HIGH);
+    delay(config_.PttTxDelayMs);
+  } else {
+    delay(CfgPollDelayMs);
+  }
   return (LoRa.beginPacket() == 1);
 }
 
@@ -368,7 +378,13 @@ void Service::onRigTx(byte b)
 
 void Service::onRigTxEnd()
 {
-  LoRa.endPacket(true);
+  if (config_.PttEnable) {
+    LoRa.endPacket(false);
+    delay(config_.PttTxTailMs);
+    digitalWrite(config_.PttPin, LOW);
+  } else {
+    LoRa.endPacket(true);
+  }
 }
 
 void Service::onSerialTx(byte b)
@@ -402,6 +418,14 @@ void Service::onControlCommand(Cmd cmd, byte value)
       Serial.print("CSMA SlotTime: "); Serial.println(value);
       csmaSlotTime_ = (long)value * 10;
       break;
+    case Cmd::TxDelay:
+      Serial.print("TX delay: "); Serial.println(value);
+      config_.PttTxDelayMs = (long)value * 10;
+      break;
+    case Cmd::TxTail:
+      Serial.print("TX tail: "); Serial.println(value);
+      config_.PttTxTailMs = (long)value * 10;
+      break;
     default:
       break;
   }