Bugfixes (#15)

* Add Heltec module support

* Fix issue #14 HW Capture not working on Mega

* Fix issue #12 Compile errors

Update code to work with ESP32 support v2.0.4 (current on Arduino and on PlatformIO).

* Get rid of 'undefined LED_BUILTIN' errors.

* Fix compilation errors on Heltek Dev Kit 32

* Add yet another Heltec board category

* Update .gitignore

* Remove excluded files

.gitignore

@@ -5,4 +5,5 @@
 .gcc-flags.json
 .pio
 .vscode
+.vscode/*
 **/hardware/*backups/

Config.h

@@ -19,12 +19,16 @@
 #define config_h
 
 // The following logic should work for all supported platforms, hopefully.
+#if defined(ARDUINO_heltec_wifi_kit_32) || defined(ARDUINO_WIFI_KIT_32)
+#define ARDUINO_HELTEC_WIFI_KIT_32
+#endif
+
 #if defined(ESP_PLATFORM)
   #if !defined(ESP32)
     #define ESP32
   #endif
 #elif defined(ESP8266)
-// nothing needs done here.
+  // nothing needs done here.
 #elif defined(ARDUINO_AVR_UNO) || defined(ARDUINO_AVR_NANO)
   #define ARDUINO_UNO_NANO
 #elif defined(ARDUINO_AVR_MEGA2560)
@@ -89,7 +93,7 @@
   #define OLED_I2CADDRESS 0x3C
   #define SCREEN_WIDTH 128
   #define SCREEN_HEIGHT 32
-#elif defined(ESP32)    // Heltec Kit 32 has pins 4/15 predefined for I2C.
+#elif defined(ARDUINO_HELTEC_WIFI_KIT_32)    // Heltec Kit 32 has pins 4/15 predefined for I2C.
   // #define SDA_OLED 4
   // #define SCL_OLED 15
   #define OLED_RESET 16

DCCInspector-EX.ino

@@ -228,9 +228,25 @@ void setup() {
           "    **"));
   }
 
-// Start OLED display (if required).
 #if defined(USE_OLED)
+  // Start OLED display (if required).
   OledDisplay.begin(SDA_OLED, SCL_OLED);
+#if defined(ARDUINO_HELTEC_WIFI_KIT_32)
+  // Read battery voltage from pin GPIO37
+  // The battery measurement is enabled via pin GPIO21
+  digitalWrite(21, 0);
+  analogSetWidth(12);  // 12 bits = 0-4095
+  analogSetPinAttenuation(37, ADC_11db);
+  adcAttachPin(37);
+
+  uint32_t batValue = analogRead(37);
+  // An input value of around 2600 is obtained for a
+  // a measured battery voltage of 4100mV.  
+  uint16_t batMV = batValue * 41 / 26;
+  if (batMV < 3400) OledDisplay.append("Battery Low");
+  digitalWrite(21, 1);  // Disable battery monitor
+
+#endif
   OledDisplay.append("Initialising..");
 #endif
 
@@ -325,6 +341,13 @@ void loop() {
 #endif
       Serial.println(F("*** Inactivity detected -- going to sleep ***"));
       delay(5000);
+#if defined(ARDUINO_HELTEC_WIFI_KIT_32)
+      // Turn off WiFi
+      WiFi.disconnect(true);
+      // Turn off Vext power to screen on Heltec Kit 32 V2
+      pinMode(21, OUTPUT);
+      digitalWrite(21, 1);
+#endif
       esp_deep_sleep_start();
     }
 #endif

EventTimer.h

@@ -23,7 +23,7 @@
  * 
  */
 
-#if defined(ARDUINO_UNO_NANO) || defined(ARDUINO_AVR_MEGA)
+#if defined(ARDUINO_UNO_NANO) || defined(ARDUINO_AVR_MEGA2560)
   #include "EventTimer_AtMega.h"
 #elif defined(ESP32)
   #include "EventTimer_ESP32.h"

EventTimer_ESP32.h

@@ -42,7 +42,7 @@
  */
 typedef bool EventHandler(unsigned long eventInterval);
 
-static void IRAM_ATTR isr_handler(void *);
+static bool IRAM_ATTR captureCallbackFunction(mcpwm_unit_t mcpwm, mcpwm_capture_channel_id_t cap_channel, const cap_event_data_t *edata, void *user_data);
 
 class EventTimerClass {
 public:
@@ -60,13 +60,19 @@ class EventTimerClass {
     // is scheduled.  The interrupt response code is responsible for retrieving the captured value.
     mcpwm_gpio_init(MCPWM_UNIT_0, MCPWM_CAP_0, INPUTPIN);
     mcpwm_gpio_init(MCPWM_UNIT_0, MCPWM_CAP_1, INPUTPIN);
-    mcpwm_capture_enable(MCPWM_UNIT_0, MCPWM_SELECT_CAP0, MCPWM_POS_EDGE, 0);  
-            //capture signal on positive edge, prescale = 0 i.e. 800,000,000 counts is equal to one second
-    mcpwm_capture_enable(MCPWM_UNIT_0, MCPWM_SELECT_CAP1, MCPWM_NEG_EDGE, 0);  
-            //capture signal on negative edge, prescale = 0 i.e. 800,000,000 counts is equal to one second
+    mcpwm_capture_config_t cap_conf;
+    cap_conf.capture_cb = captureCallbackFunction;
+    cap_conf.user_data = NULL;
+    cap_conf.cap_prescale = 1;  //no prescale, i.e. 800,000,000 counts equals one second.
+    cap_conf.cap_edge = MCPWM_POS_EDGE;
+    mcpwm_capture_enable_channel(MCPWM_UNIT_0, MCPWM_SELECT_CAP0, &cap_conf);  
+            //capture signal on positive edge
+    cap_conf.cap_edge = MCPWM_NEG_EDGE;
+    mcpwm_capture_enable_channel(MCPWM_UNIT_0, MCPWM_SELECT_CAP1, &cap_conf);  
+            //capture signal on negative edge
     MCPWM0.int_ena.cap0_int_ena = 1;                            // Enable interrupt on CAP0 signal
     MCPWM0.int_ena.cap1_int_ena = 1;                            // Enable interrupt on CAP1 signal
-    mcpwm_isr_register(MCPWM_UNIT_0, isr_handler, NULL, ESP_INTR_FLAG_IRAM, NULL); // Set ISR Handler
+    //mcpwm_isr_register(MCPWM_UNIT_0, isr_handler, NULL, ESP_INTR_FLAG_IRAM, NULL); // Set ISR Handler
     return true;
   };
 
@@ -84,24 +90,11 @@ class EventTimerClass {
   //  and to invoke the user program's handler.  The user's handler is passed the 
   //  number of ticks elapsed since the last valid interrupt.  It returns true/false to 
   //  indicate if this interrupt is deemed to be 'valid' or not.
-   void IRAM_ATTR processInterrupt() {
+   void IRAM_ATTR processInterrupt(mcpwm_capture_channel_id_t cap_channel) {
     // Get current micros() value to support elapsedTicksSinceLastEvent().
     thisEventMicros = micros();
 
-    // Check which interrupt is pending.
-    mcpwm_capture_signal_t capture = MCPWM_SELECT_CAP0;
-    if (MCPWM0.int_st.cap0_int_st) {
-      capture = MCPWM_SELECT_CAP0;
-      MCPWM0.int_clr.cap0_int_clr = 1; // Clear capture 0 interrupt
-    } else if (MCPWM0.int_st.cap1_int_st) {
-      capture = MCPWM_SELECT_CAP1;
-      MCPWM0.int_clr.cap1_int_clr = 1; // Clear capture 1 interrupt
-    } else
-      return;         // No interrupt pending.
-
-    //unsigned long edge = mcpwm_capture_signal_get_edge(MCPWM_UNIT_0, capture); // 1=positive edge, 2=negative edge
-
-    unsigned long thisEventTicks = mcpwm_capture_signal_get_value(MCPWM_UNIT_0, capture); //get capture signal counter value
+    unsigned long thisEventTicks = mcpwm_capture_signal_get_value(MCPWM_UNIT_0, cap_channel); //get capture signal counter value
     unsigned long eventInterval = thisEventTicks - lastValidEventTicks;
     bool accepted = callUserHandler(eventInterval);
     if (accepted) {
@@ -128,8 +121,9 @@ class EventTimerClass {
 
 EventTimerClass EventTimer;
 
-static void IRAM_ATTR isr_handler(void *) {
-  EventTimer.processInterrupt();
+static bool IRAM_ATTR captureCallbackFunction(mcpwm_unit_t mcpwm, mcpwm_capture_channel_id_t cap_channel, const cap_event_data_t *edata, void *user_data) {
+  EventTimer.processInterrupt(cap_channel);
+  return false;
 }
 
 #endif

HttpManager.cpp

@@ -51,7 +51,9 @@ WebServer HttpManagerClass::server;
 //  It sends a static web page that includes an updating IFRAME where the dynamic data
 //  will be displayed.
 void HttpManagerClass::handleRoot() {
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 1);
+#endif
   processArguments();
   int refreshTime = DCCStatistics.getRefreshTime();
   String temp = 
@@ -106,19 +108,27 @@ void HttpManagerClass::handleRoot() {
   server.send(200, "text/html", temp);
   temp = "";  // release space held
 
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 0);
+#endif
 }
 
 // Function to handle the request for dynamic data (http://server/data).
 void HttpManagerClass::handleData() {
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 1);
+#endif
   server.send(200, "text/html", HttpManager.getHtmlString());
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 0);
+#endif
 }
 
 // Function to handle any other requests.  Returns "404 Not Found".
 void HttpManagerClass::handleNotFound() {
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 1);
+#endif
   String message = "File Not Found\n\n";
   message += "URI: ";
   message += server.uri();
@@ -133,7 +143,9 @@ void HttpManagerClass::handleNotFound() {
   }
 
   server.send(404, "text/plain", message);
+#if defined(LED_BUILTIN)
   digitalWrite(LED_BUILTIN, 0);
+#endif
 }
 
 void HttpManagerClass::processArguments() {
@@ -146,7 +158,7 @@ void HttpManagerClass::processArguments() {
 }
 
 #if defined(ESP32)
-void HttpManagerClass::WiFiEvent (WiFiEvent_t event, system_event_info_t info) {
+void HttpManagerClass::WiFiEvent (arduino_event_id_t event) {
   switch (event) {
     case SYSTEM_EVENT_STA_WPS_ER_SUCCESS:
       Serial.print(F("[WPS Successful]"));
@@ -184,7 +196,6 @@ bool HttpManagerClass::begin(const char *ssid, const char *password, const char
   #if defined(ESP32)
   esp_wps_config_t config;
   memset(&config, 0, sizeof(config));
-  config.crypto_funcs = &g_wifi_default_wps_crypto_funcs;
   config.wps_type = WPS_TYPE_PBC;
 
   WiFi.onEvent (WiFiEvent);

HttpManager.h

@@ -67,7 +67,7 @@ class HttpManagerClass {
     static void handleNotFound();
     static void handleData();
     #if defined(ESP32)
-    static void WiFiEvent (WiFiEvent_t event, system_event_info_t info);
+    static void WiFiEvent (arduino_event_id_t event);
     #endif
     // Flag whether connected or not.
     bool connected = false; 

OledDisplay.cpp

@@ -21,12 +21,12 @@
  * is used for scrolling the display.
  */
 
+#include "OledDisplay.h"
+
 #include "Config.h"
 
 #ifdef USE_OLED
 
-#include "OledDisplay.h"
-
 // Function called to initialise the object instance.  
 //  Connects to the OLED display and puts it into a 
 //  suitable mode.

OledDisplay.h

@@ -36,6 +36,8 @@
 #ifndef oleddisplay_h
 #define oleddisplay_h
 
+#include <Adafruit_SSD1306.h>
+
 #include "Config.h"
 
 // Only compile if USE_OLED is defined.
@@ -45,8 +47,6 @@
 #include "DCCStatistics.h"
 #include "StringBuilder.h"
 
-#include <Adafruit_SSD1306.h>
-
 class OledDisplayClass {
 public:
   // Function called to initialise the object instance.  

platformio.ini

@@ -10,7 +10,8 @@
 
 [platformio]
 default_envs = 
-    esp32
+    esp32_heltec
+    esp32_generic
     esp8266
     nano
     nanoNew
@@ -26,9 +27,16 @@ lib_deps =
   adafruit/Adafruit SSD1306
 build_flags = -Wall -Wextra
 
-[env:esp32]
+[env:esp32_heltec]
 platform = espressif32
-board = heltec_wifi_kit_32
+board = heltec_wifi_kit_32_v2
+framework = arduino
+lib_deps = 
+    ${env.lib_deps}
+
+[env:esp32_generic]
+platform = espressif32
+board = nodemcu-32s
 framework = arduino
 lib_deps = 
     ${env.lib_deps}