#5 calculate clock division or multiplier

tri_ger_plus/time.ino

@@ -9,27 +9,57 @@ uint32_t nextClockOffAtMillis;
 uint32_t prevClockOffAtMillis;
 
 void doTimeStuff() {
+
+  // collect the knob value
+  // then slice the range in half
+  // then normalize that half range so that 512 is in the center
+  // split the half range into five roughly equal parts 100 units apart
+  // convert the value into an integer ranging from -5 to +5
+  // use the sign of the integer to determine if we multiply or divide
+  // take the absolute value to use a lookup. range from 0-4 will be 2^x
+  // 5 will equal 24
+  // therefore zero will map to -5 which will divide a 24ppqn signal to quarter notes
+  // therefore 1023 will map to +5 which will accept quarter notes and output 24ppqn
+  // therefore 512 will map to 2^0=1 which will neither multiply nor divide
+
+  // y = floor((x10+512)/1023-5)+5
+  const int multiplier_step = (getMux(clock_div_knob) * 10 + 512) / 1023 - 5;
+  const int multiplier = abs(multiplier_step) == 5
+    ? 24
+    : 1 << abs(multiplier_step);
+
+
+//  int multiplier = getMux(clock_div_knob) * 24 / 512 - 24;
+  lights(0, multiplier);
+
   const uint32_t now = millis();
 
   bool clockIsHigh = getMux(clock_div_cv) > 512;
 
+
   if(clockIsHigh) {
     if(!prevClockWasHigh) { //new pulse
       uint32_t newPeriod = now - prevClockMillis;
       prevClockMillis = now;
 
       periodPrediction = bpm.Predict(newPeriod);
-      lights(0, byte(periodPrediction)); //debug
+//      lights(0, byte(periodPrediction)); //debug
 
       prevClockOffAtMillis = nextClockOffAtMillis;
-      nextClockOffAtMillis = now + periodPrediction + 25;
+
+      if(multiplier_step <= 0) { // multiply period, go slower
+        nextClockOffAtMillis = now + periodPrediction * multiplier + 25;
+      } else { // divide period, go faster
+        nextClockOffAtMillis = now + periodPrediction / multiplier + 25;
+      }
+
     }
     prevClockWasHigh = true;
   } else {
     prevClockWasHigh = false;
   }
 
-  int multiplier = getMux(clock_div_knob);
+
 
 
   if(now < prevClockOffAtMillis){