Adding rudimentary flex callback.

Author: finnkuusisto

Devlpr.cpp

@@ -26,6 +26,17 @@ void Devlpr::tick()
         microsSinceEMG = 0L;
         // NOTE just a best effort to run on time
     }
+    ////////////////
+    // Flex Check //
+    ////////////////
+    // accrue micros on the micros since last check
+    microsSinceFlexCheck += microsDelta;
+    // check if enough time has passed to check for a flex
+    if (microsSinceFlexCheck >= MICROS_SCHED_FLEX) {
+        flexCheck(currMicros);
+        // and update micros since
+        microsSinceFlexCheck = 0L;
+    }
     ////////////////////////////
     // User Function Schedule //
     ////////////////////////////
@@ -113,6 +124,16 @@ int Devlpr::scheduleFunction(void (*f)(Devlpr *d), unsigned int millisPer)
     return (numFuncs - 1);
 }
 
+void Devlpr::setFlexCallback(void (*f)(Devlpr *d), float threshMult,
+    unsigned int millisCooldown)
+{
+    // set the callback
+    onFlexFunc = f;
+    // and the parameters
+    flexThreshMultiple = threshMult;
+    flexCooldownMicros = millisCooldown * 1000L;
+}
+
 void Devlpr::readEMG()
 {
     // want bufInd to sit on the most recent value until tick
@@ -129,3 +150,22 @@ void Devlpr::readEMG()
     // now replace
     buf[bufInd] = emgVal;
 }
+
+void Devlpr::flexCheck(unsigned long currMicros)
+{
+    // to check cooldown
+    unsigned long microsDelta = currMicros - prevFlexMicros;
+    // the actual flex check
+    unsigned int peakToPeakThresh = prevPeakToPeak * flexThreshMultiple;
+    unsigned int currPeakToPeak = windowPeakToPeakAmplitude();
+    // need an attached function, cooldown passed, and a peak change
+    if (onFlexFunc && microsDelta >= flexCooldownMicros &&
+        currPeakToPeak >= peakToPeakThresh) {
+        // hit the callback
+        onFlexFunc(this);
+        // and update the previous confirmed flex
+        prevFlexMicros = currMicros;
+    }
+    // need to update the current peak-to-peak for next time
+    prevPeakToPeak = currPeakToPeak;
+}

Devlpr.h

@@ -14,6 +14,8 @@ class Devlpr
         unsigned int windowPeakAmplitude();
         unsigned int windowPeakToPeakAmplitude();
         int scheduleFunction(void (*f)(Devlpr *d), unsigned int millisPer);
+        void setFlexCallback(void (*f)(Devlpr *d), float threshMult=1.5,
+            unsigned int millisCooldown=400);
     private:
         // emg buffer bookkeeping
         static const byte BUFSIZE = 32; // power of 2 for fast integer avg calc
@@ -29,6 +31,16 @@ class Devlpr
         // emg scheduling
         static const unsigned long MICROS_SCHED_EMG = 1000L;
         unsigned long microsSinceEMG = 0L;
+        // onFlex scheduling
+        static const unsigned long MICROS_SCHED_FLEX = 1000L * BUFSIZE; // once per buffer fill
+        unsigned long microsSinceFlexCheck = 0L;
+        // flex tracking
+        void (*onFlexFunc)(Devlpr *d) = NULL;
+        void flexCheck(unsigned long currMicros);
+        unsigned long prevFlexMicros = 0L;
+        unsigned int prevPeakToPeak = 0L;
+        unsigned long flexCooldownMicros = 400000L; // 400ms
+        float flexThreshMultiple = 1.5;
         // user function scheduling
         static const byte FUNCMAX = 8;
         void (*funcs[FUNCMAX])(Devlpr *d);

libdevlpr.ino

@@ -7,11 +7,16 @@ void printEMG(Devlpr *d) {
     Serial.println(result);
 }
 
+void writeFlex(Devlpr *d) {
+    Serial.println("FLEX");
+}
+
 void setup() {
     Serial.begin(2000000);
     // add our print function to our DEVLPR schedule
     // try to run once every 1ms
-    devlpr.scheduleFunction(printEMG, 1);
+    //devlpr.scheduleFunction(printEMG, 1);
+    devlpr.setFlexCallback(writeFlex);
 }
 
 void loop() {