Diff: src/main.cpp

Revision:

0:973a5bbb2a17

Child:

1:80bc4501abc5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main.cpp	Thu Nov 21 08:46:20 2019 +0000
@@ -0,0 +1,69 @@
+
+#include "mbed.h"
+#define u16_max 65526
+AnalogIn mic(PB_0);
+DigitalOut vcc(GPIO0);
+Serial pc(UART_TX, UART_RX, 115200);
+const int sampleTime = 50;
+int micOut;
+// Find the Peak-to-Peak Amplitude Function
+int findPTPAmp(float* sampleArr){
+// Time variables to find the peak-to-peak amplitude
+   
+   unsigned int PTPAmp = 0; 
+
+// Signal variables to find the peak-to-peak amplitude
+   unsigned int maxAmp = 0;
+   unsigned int minAmp = 1023;
+
+// Find the max and min of the mic output within the 50 ms timeframe
+    for(int i=0; i<8000; i++)
+   {
+      if( sampleArr[i] < 1023) //prevent erroneous readings
+      {
+        if (sampleArr[i] > maxAmp)
+        {
+          maxAmp = sampleArr[i]; //save only the max reading
+        }
+        else if (sampleArr[i] < minAmp)
+        {
+          minAmp = sampleArr[i]; //save only the min reading
+        }
+      }
+   }
+
+  PTPAmp = maxAmp - minAmp; // (max amp) - (min amp) = peak-to-peak amplitude
+  double micOut_Volts = (PTPAmp * 3.3) / 1024; // Convert ADC into voltage
+
+  //Uncomment this line for help debugging (be sure to also comment out the VUMeter function)
+  //Serial.println(PTPAmp); 
+
+  //Return the PTP amplitude to use in the soundLevel function. 
+  // You can also return the micOut_Volts if you prefer to use the voltage level.
+  return PTPAmp;   
+}
+
+void record(float* sampleArr) {
+    //record sound for 1 second
+    for(int i=0; i<8000; i++) {
+        sampleArr[i] = mic.read(); //put samples in array
+        wait(0.000125f); //sample rate of 8000 Hz
+    }  
+}
+
+int main(){
+    float sampleArr[8000]; //used to store sound 
+    pc.printf("\r\n Sparkfun MEM Microphone Test\n");   
+    pc.printf("******************\n");
+    vcc = 1;
+    unsigned int val;
+    int ptpAmp;
+    while(1){
+        wait(0.2); 
+        record(sampleArr); 
+        ptpAmp=findPTPAmp(sampleArr);
+    }
+}
+
+     
+