proof-of-concept of a board-agnostic, simple micros()-check-based mode

src/platforms/generic.h

@@ -0,0 +1,30 @@
+#include <Arduino.h>
+
+//#define ATOMIC(X) noInterrupts(); X; interrupts();
+#define ATOMIC(X) X;
+
+// forward declaration of ISR
+void uClockHandler();
+
+uint32_t uclock_last_time_ticked;
+uint32_t uclock_us_interval;
+
+// call this as often as possible to tick the uClock
+void uClockCheckTime(uint32_t micros_time) {
+    if (micros_time - uclock_last_time_ticked >= uclock_us_interval) {
+        uclock_last_time_ticked = micros();
+        uClockHandler();
+    }
+}
+
+void initTimer(uint32_t init_clock)
+{
+    // basically nothing to do for software-implemented version..?
+    uclock_last_time_ticked = micros();
+}
+
+void setTimer(uint32_t us_interval)
+{
+    uclock_us_interval = us_interval;
+    Serial.printf("setTimer(%d)\n", us_interval); Serial.flush();
+}

src/uClock.cpp

@@ -28,36 +28,52 @@
 #include "uClock.h"
 
 //
-// General Arduino AVRs port
+// Generic, board-agnostic, not-accurate, no-interrupt, software-only port
 //
-#if defined(ARDUINO_ARCH_AVR)
+#if !defined(USE_UCLOCK_GENERIC)
+    //
+    // General Arduino AVRs port
+    //
+    #if defined(ARDUINO_ARCH_AVR)
         #include "platforms/avr.h"
-#endif
+        #define UCLOCK_PLATFORM_FOUND
-//
+    #endif
-// Teensyduino ARMs port
+    //
-//
+    // Teensyduino ARMs port
-#if defined(TEENSYDUINO)
+    //
+    #if defined(TEENSYDUINO)
         #include "platforms/teensy.h"
-#endif
+        #define UCLOCK_PLATFORM_FOUND
-//
+    #endif
-// Seedstudio XIAO M0 port
+    //
-//
+    // Seedstudio XIAO M0 port
-#if defined(SEEED_XIAO_M0)
+    //
+    #if defined(SEEED_XIAO_M0)
         #include "platforms/samd.h"
-#endif
+        #define UCLOCK_PLATFORM_FOUND
-//
+    #endif
-// ESP32 family
+    //
-//
+    // ESP32 family
-#if defined(ARDUINO_ARCH_ESP32) || defined(ESP32)
+    //
+    #if defined(ARDUINO_ARCH_ESP32) || defined(ESP32)
         #include "platforms/esp32.h"
-#endif
+        #define UCLOCK_PLATFORM_FOUND
-//
+    #endif
-// STM32XX family
+    //
-//
+    // STM32XX family
-#if defined(ARDUINO_ARCH_STM32)
+    //
+    #if defined(ARDUINO_ARCH_STM32)
         #include "platforms/stm32.h"
+        #define UCLOCK_PLATFORM_FOUND
+    #endif
+#endif
+
+#if !defined(UCLOCK_PLATFORM_FOUND)
+    #pragma message ("NOTE: uClock is using the 'generic' approach instead of specific board support, because board is not supported or because of USE_UCLOCK_GENERIC build flag.")
+    #include "platforms/generic.h"
 #endif
 
+
 //
 // Platform specific timer setup/control
 //
@@ -72,6 +88,7 @@ void uclockInitTimer()
 
 void setTimerTempo(float bpm) 
 {
+    Serial.printf("setTimerTempo(%3.3f)..", bpm);
     setTimer(uClock.bpmToMicroSeconds(bpm));
 }
 
@@ -119,7 +136,7 @@ void uClockClass::init()
 
 uint32_t uClockClass::bpmToMicroSeconds(float bpm) 
 {
-    return (60000000 / ppqn / bpm);
+    return (60000000.0f / (float)ppqn / bpm);
 }
 
 void uClockClass::setPPQN(PPQNResolution resolution)