Core panic in TxManage, concluding gate in timer callback - using digitalwrite is BAD @ ISRL!!!

Now use FreeRTOS queue to pass the actual event down.

src/Afterburner.cpp

@@ -128,8 +128,8 @@
 
 const int FirmwareRevision = 32;
 const int FirmwareSubRevision = 0;
-const int FirmwareMinorRevision = 0;
-const char* FirmwareDate = "30 Mar 2020";
+const int FirmwareMinorRevision = 3;
+const char* FirmwareDate = "9 Apr 2020";
 
 
 #ifdef ESP32

src/Protocol/TxManage.cpp

@@ -22,6 +22,7 @@
 #include "TxManage.h"
 #include "../Utility/NVStorage.h"
 #include "../Utility/helpers.h"
+#include "freertos/queue.h"
 
 //#define DEBUG_THERMOSTAT
 
@@ -51,6 +52,31 @@ extern void DebugReportFrame(const char* hdr, const CProtocol&, const char* ftr)
 unsigned long CTxManage::m_nStartTime = 0;
 int CTxManage::m_nTxGatePin = 0;
 
+// Timer callback operates at ISRL
+// this means we should avoid any function NOT in IRAM.
+// Sadly digitalWrite falls into this category, so use a FreeRTOS queue
+// to push the end event handling into a non ISRL task
+
+static QueueHandle_t txGate_queue = NULL;
+static int lclTxGatePin = 0;
+
+// static function used for the tx gate termination 
+static void IRAM_ATTR GateTerminateCallback()
+{
+  uint32_t gpio_num = lclTxGatePin;
+  xQueueSendFromISR(txGate_queue, &gpio_num, NULL);
+}
+
+static void TxGateConclude(void* arg)
+{
+    uint32_t io_num;
+    for(;;) {
+        if(xQueueReceive(txGate_queue, &io_num, portMAX_DELAY)) {
+          digitalWrite(io_num, LOW);   // terminate Tx Gate
+        }
+    }
+}
+
 CTxManage::CTxManage(int TxGatePin, HardwareSerial& serial) : 
   m_BlueWireSerial(serial),
   m_TxFrame(CProtocol::CtrlMode)
@@ -61,6 +87,7 @@ CTxManage::CTxManage(int TxGatePin, HardwareSerial& serial) :
   m_bTxPending = false;
   m_nStartTime = 0;
   m_nTxGatePin = TxGatePin;
+  lclTxGatePin = TxGatePin;
   _rawCommand = 0;
   m_HWTimer = NULL;
 }
@@ -68,7 +95,9 @@ CTxManage::CTxManage(int TxGatePin, HardwareSerial& serial) :
 // static function used for the tx gate termination 
 void CTxManage::GateTerminate()
 {
-  digitalWrite(m_nTxGatePin, LOW);   // default to receive mode
+  uint32_t gpio_num = m_nTxGatePin;
+  xQueueSendFromISR(txGate_queue, &gpio_num, NULL);
+//  digitalWrite(m_nTxGatePin, LOW);   // default to receive mode
   m_nStartTime = 0;                  // cancel, we are DONE
 }
 
@@ -78,12 +107,19 @@ void CTxManage::begin()
   pinMode(m_nTxGatePin, OUTPUT);
   digitalWrite(m_nTxGatePin, LOW);   // default to receive mode
 
+//create a queue to handle gpio event from isr
+  txGate_queue = xQueueCreate(10, sizeof(uint32_t));
+  //start gpio task
+  xTaskCreate(TxGateConclude, "Tx Gate Conclude", 2048, NULL, configMAX_PRIORITIES-2, NULL);
+
   // use a hardware timer to terminate the Tx gate shortly after the completion of the 24 byte transmit packet
   m_HWTimer = timerBegin(2, 80, true);
   //set time in uS of Tx gate from when actual tx data bytes are loaded 
   // 240 bits @ 25000bps is 9.6ms, we'll use 9.7ms for a bit of tolerance
   timerAlarmWrite(m_HWTimer, 10000-300, false); 
-  timerAttachInterrupt(m_HWTimer, &GateTerminate, true);     
+  // timerAttachInterrupt(m_HWTimer, &GateTerminate, true);     
+  timerAttachInterrupt(m_HWTimer, &GateTerminateCallback, true);     
+  
   timerAlarmDisable(m_HWTimer); //disable interrupt for now
   timerSetAutoReload(m_HWTimer, false);
 }
@@ -299,6 +335,7 @@ CTxManage::CheckTx(unsigned long timenow)
       // Tx gate remains held high
       // it is then brought low by the timer alarm callback, which also cancels m_nStartTime
       m_bTxPending = false;
+      m_nStartTime = 0;
       m_BlueWireSerial.write(m_TxFrame.Data, 24);  // write native binary values
       timerWrite(m_HWTimer, 0);       //reset tx gate timeout  
       timerAlarmEnable(m_HWTimer);    // timeout will cause cessation of the Tx gate