ignore peaks

src/counter.c

@@ -19,6 +19,8 @@ const int SPI_SPEED = 1000000;
 
 config_t cfg;
 
+const char EPSILON_KEY = "epsilon";
+const double DEFAULT_EPSILON = 0.01;
 
 void isr() {
   static uint32_t lastCounter = 0;
@@ -59,6 +61,7 @@ void start() {
 }
 
 int main (void) {
+
   readConfig();
   init();
   ledInit();
@@ -66,12 +69,25 @@ int main (void) {
   influxInit(&cfg);
   start();
 
+  double epsilon;
+  if (! config_lookup_float(&cfg, EPSILON_KEY, &epsilon)) {
+    epsilon = DEFAULT_EPSILON;
+  }
+  
 
+  double lastF = 0;
+  bool settled = false;
   uint8_t ledTick = 0;  
   while (1) {
     uint32_t diff = ringbufferGet();
   
     double f = 1.0 / (((double) diff) / 1000000.0);
+
+    if (settled && (abs(f - lastF) > epsilon)) {
+      printf("Current f=%f, last f=%f, gradient too large, skipped\n", f, lastF);
+      f = lastF;
+    }
+    lastF = f;
 //    printf("%f\n", f);
     influxAddFrequency(f);
 
@@ -79,7 +95,9 @@ int main (void) {
     if (ledTick == 50) {
       ledTick = 0;
       led(E_GREEN, false);
+      settled = true;
     }
+
   }
 
   // will never be reached