Experimental ESP32 support using espressif arduino-esp32 core

dcf77.cpp

@@ -1876,6 +1876,42 @@ namespace Internal {
             Clock_Controller::process_1_kHz_tick_data(the_input_provider());
         }
         #endif
+
+        #if defined(ARDUINO_ARCH_ESP32)
+        hw_timer_t *timer = NULL;
+        const uint32_t GPTimer_freq = 16000000;
+        const uint32_t ticks_per_ms = GPTimer_freq/1000;
+        const uint32_t ticks_per_us = ticks_per_ms/1000;
+
+        void setup(const Clock::input_provider_t input_provider) {
+            timer = timerBegin(GPTimer_freq); // Set timer frequency to 16Mhz, 0,0625 us tick
+            timerAttachInterrupt(timer, &isr_handler);
+            timerAlarm(timer, ticks_per_ms, true, 0);  // call isr_handler function onetime after 1000 microseconds
+            the_input_provider = input_provider;
+        }
+
+        // 1000 / 16 000 000 = 1 / 16 000
+        const uint16_t inverse_timer_resolution = 16000;
+
+        void ARDUINO_ISR_ATTR isr_handler() {
+            cumulated_phase_deviation += adjust_pp16m;
+            if (cumulated_phase_deviation >= inverse_timer_resolution) {
+                cumulated_phase_deviation -= inverse_timer_resolution;
+                // cumulated drift exceeds microsecond)
+                // drop microsecond step to realign
+                timerAlarm(timer, ticks_per_ms - ticks_per_us, true, 0);
+            } else if (cumulated_phase_deviation <= -inverse_timer_resolution) {
+                cumulated_phase_deviation += inverse_timer_resolution;
+                // cumulated drift exceeds 1 microsecond
+                // insert one microsecond to realign
+                timerAlarm(timer, ticks_per_ms + ticks_per_us, true, 0);
+            } else {
+                timerAlarm(timer, ticks_per_ms, true, 0);
+            }
+
+            Clock_Controller::process_1_kHz_tick_data(the_input_provider());        
+        }
+        #endif
     }
 }
 

dcf77.h

@@ -79,13 +79,17 @@ struct Configuration {
 
     // the constant(s) below are assumed to be configured by the user of the library
 
+    #if defined(ARDUINO_ARCH_ESP32)
+    //Low memory footprint default for ESP32
+    static const bool want_high_phase_lock_resolution = false;
+    #else
     static const bool want_high_phase_lock_resolution = true;
-    //const bool want_high_phase_lock_resolution = false;
+    #endif
 
     // end of configuration section, the stuff below
     // will compute the implications of the desired configuration,
     // ready for the compiler to consume
-    #if defined(__arm__)
+    #if defined(__arm__) || defined(ARDUINO_ARCH_ESP32)
     static const bool has_lots_of_memory = true;
     #else
     static const bool has_lots_of_memory = false;
@@ -553,6 +557,19 @@ namespace Internal {
         #warning Compiling for Linux target only supported for unit test purposes. Only fake support for atomic sections. Please take care.
 
         #define CRITICAL_SECTION for (int __n = 1; __n; __n = 0)
+    #elif defined(ARDUINO_ARCH_ESP32)
+        #warning Experimental ESP32 support using espressif arduino-esp32
+        // Inspired by
+        // --> https://github.com/wizard97/SimplyAtomic/blob/master/esp32.h
+        static __inline__ void SA_iRestore(const  uint32_t *__s){
+            XTOS_RESTORE_INTLEVEL(*__s);
+        }
+
+        // Note value can be 0-15, 0 = Enable all interrupts, 15 = no interrupts
+        #define SA_ATOMIC_RESTORESTATE uint32_t _sa_saved              \
+            __attribute__((__cleanup__(SA_iRestore))) = XTOS_DISABLE_LOWPRI_INTERRUPTS
+
+        #define CRITICAL_SECTION for ( SA_ATOMIC_RESTORESTATE, _sa_done =  1; _sa_done; _sa_done = 0 )
     #else
         #error Unsupported controller architecture
     #endif