Added an example

Author: ocrdu

examples/flame/flame.ino

@@ -0,0 +1,18 @@
+// Uses two orange LEDS plus resistors on pins 4 and 7 (on the Nano 33 IoT; change for other boards).
+// Don't pull more than 7mA from any pin.
+
+#include <SAMD21turboPWM.h>
+
+TurboPWM pwm;
+
+void setup() {
+  pwm.setClockDivider(1, false);
+  pwm.timer(1, 1, 1000, true);
+}
+
+void loop() {
+  pwm.analogWrite(4, random(500, 1000));
+  delay(25);
+  pwm.analogWrite(7, random(300, 1000));
+  delay(25);
+}

src/SAMD21turboPWM.cpp

@@ -61,7 +61,7 @@ int TurboPWM::timer(int timerNumber, unsigned int TCCDiv, unsigned long int sts,
     return 0;
   }
 
-  // Derive TCC prescaler from parameter TCCDiv; default to 4
+  // Derive TCC prescaler from parameter TCCDiv; default to last known setting
   unsigned int my_TCC_CTRLA_PRESCALER_DIV;
   if (TCCDiv == 1) {
     my_TCC_CTRLA_PRESCALER_DIV = TCC_CTRLA_PRESCALER_DIV1_Val << TCC_CTRLA_PRESCALER_Pos;