Revert esp32 ISR-safe timer workaround, fixed in espressif/arduino-esp32#4684

Author: taligentx

Diff for: README.md

@@ -89,7 +89,7 @@ Poking around with a logic analyzer and oscilloscope revealed that the errors ca
       * Includes [Arduino framework support](https://github.com/esp8266/Arduino) and WiFi for ~$3USD shipped.
     - esp32:
       * Development boards: NodeMCU ESP-32S, Doit ESP32 Devkit v1, Wemos Lolin D32, etc.
-      * Includes [Arduino framework support](https://github.com/espressif/arduino-esp32), dual cores, WiFi, and Bluetooth for ~$5USD shipped.
+      * Includes [Arduino framework support](https://github.com/espressif/arduino-esp32) (v1.0.5-rc6 or newer required), dual cores, WiFi, and Bluetooth for ~$5USD shipped.
 * Possible features (PRs welcome!):
   - [DSC IT-100](https://cms.dsc.com/download.php?t=1&id=16238) emulation
   - Unlock 6-digit installer codes
@@ -103,7 +103,7 @@ Poking around with a logic analyzer and oscilloscope revealed that the errors ca
   - New: `TimeSyncNTP` example sketch - uses NTP to automatically set the panel time
   - New: [ESPHome](https://esphome.io) integration example (located in the `extras` directory) - thanks to [Dilbert66](https://github.com/Dilbert66) for this contribution!
   - New: `KeybusReaderIP` example sketch enables Keybus data access over IP, thanks to [aboulfad](https://github.com/aboulfad) for this contribution!
-  - New: esp32 microcontroller support
+  - New: esp32 microcontroller support - requires [Arduino-esp32](https://github.com/espressif/arduino-esp32) v1.0.5-rc6 or newer
   - New: Features for sketches:
       * `ready` and `disabled` track partition status
       * `setTime()` sets the panel date and time

Diff for: src/dscKeybusInterface.cpp

@@ -59,41 +59,7 @@ volatile byte dscKeybusInterface::moduleSubCmd;
 volatile unsigned long dscKeybusInterface::clockHighTime;
 volatile unsigned long dscKeybusInterface::keybusTime;
 
-// Workaround for ESP32 hardware timer interrupt functions called from within an ISR:
-// https://github.com/crankyoldgit/IRremoteESP8266/pull/1351
 #if defined(ESP32)
-typedef struct {
-    union {
-        struct {
-            uint32_t reserved0:   10;
-            uint32_t alarm_en:     1;
-            uint32_t level_int_en: 1;
-            uint32_t edge_int_en:  1;
-            uint32_t divider:     16;
-            uint32_t autoreload:   1;
-            uint32_t increase:     1;
-            uint32_t enable:       1;
-        };
-        uint32_t val;
-    } config;
-    uint32_t cnt_low;
-    uint32_t cnt_high;
-    uint32_t update;
-    uint32_t alarm_low;
-    uint32_t alarm_high;
-    uint32_t load_low;
-    uint32_t load_high;
-    uint32_t reload;
-} hw_timer_reg_t;
-
-typedef struct hw_timer_s {
-        hw_timer_reg_t * dev;
-        uint8_t num;
-        uint8_t group;
-        uint8_t timer;
-        portMUX_TYPE lock;
-} hw_timer_t;
-
 hw_timer_t *timer0 = NULL;
 portMUX_TYPE timer0Mux = portMUX_INITIALIZER_UNLOCKED;
 #endif
@@ -715,7 +681,7 @@ void IRAM_ATTR dscKeybusInterface::dscClockInterrupt() {
 
   // esp32 timer0 calls dscDataInterrupt() in 250us
   #elif defined(ESP32)
-  timer0->dev->config.enable = 1;
+  timerStart(timer0);
   portENTER_CRITICAL(&timer0Mux);
   #endif
 
@@ -812,7 +778,7 @@ void dscKeybusInterface::dscDataInterrupt() {
 void ICACHE_RAM_ATTR dscKeybusInterface::dscDataInterrupt() {
 #elif defined(ESP32)
 void IRAM_ATTR dscKeybusInterface::dscDataInterrupt() {
-  timer0->dev->config.enable = 0;
+  timerStop(timer0);
   portENTER_CRITICAL(&timer0Mux);
 #endif
 

Diff for: src/dscKeybusInterface.h

@@ -26,14 +26,18 @@
 const byte dscPartitions = 4;   // Maximum number of partitions - requires 19 bytes of memory per partition
 const byte dscZones = 4;        // Maximum number of zone groups, 8 zones per group - requires 6 bytes of memory per zone group
 const byte dscBufferSize = 10;  // Number of commands to buffer if the sketch is busy - requires dscReadSize + 2 bytes of memory per command
-#elif defined(ESP8266) || defined(ESP32)
+const byte dscReadSize = 16;    // Maximum bytes of a Keybus command
+#elif defined(ESP8266)
 const byte dscPartitions = 8;
 const byte dscZones = 8;
 const byte dscBufferSize = 50;
-#endif
-
-// Maximum bytes of a Keybus command
 const byte dscReadSize = 16;
+#elif defined(ESP32)
+const byte dscPartitions = 8;
+const byte dscZones = 8;
+const DRAM_ATTR byte dscBufferSize = 50;
+const DRAM_ATTR byte dscReadSize = 16;
+#endif
 
 // Exit delay target states
 #define DSC_EXIT_STAY 1
@@ -144,7 +148,7 @@ class dscKeybusInterface {
     // True if dscBufferSize needs to be increased
     static volatile bool bufferOverflow;
 
-    // Timer interrupt function to capture data - declared as public for use by AVR Timer2
+    // Timer interrupt function to capture data - declared as public for use by AVR Timer1
     static void dscDataInterrupt();
 
     // Deprecated