Program to control Electret Microphone Amplifier - MAX9814 from adafruit. Allows: To sample analogue voltage to transform into rough sound level. Transfer sound level to visual indicator, volume bar such as 4 LEDs on LPC11U24.

Dependencies:   MAX9814_Electret_Microphone_LED_Volume_Indicator mbed

Revision:
1:380e6ab41172
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Hammer_MicrophoneSensor.cpp	Sun Nov 02 17:12:22 2014 +0000
@@ -0,0 +1,104 @@
+#include "mbed.h"
+#include "Hammer_MicrophoneSensor.h"
+
+MAX9814::MAX9814(PinName pin): _pin(pin), _led1(LED1), _led2(LED2), _led3(LED3), _led4(LED4) {
+    calibration();
+}
+
+
+void MAX9814::led_array(float x ) {
+
+    if (_value<x+0.05) {
+            _led1=0;
+            _led2=0;
+            _led3=0;
+            _led4=0;
+    }
+    if (_value>x+0.05&&_value<0.5+x) {
+            _led1=1;
+            _led2=0;
+            _led3=0;
+            _led4=0;
+    }
+    if (_value>0.5+x&&_value<1+x) {
+            _led1=1;
+            _led2=1;
+            _led3=0;
+            _led4=0;
+    }
+    if (_value>1+x&&_value<1.2+x) {
+            _led1=1;
+            _led2=1;
+            _led3=1;
+            _led4=0;
+    }
+    if (_value>1.2+x&&_value<2.8+x) {
+            _led1=1;
+            _led2=1;
+            _led3=1;
+            _led4=1;
+    }
+}
+
+float MAX9814::calibration() {
+    
+    _t.start();
+    _t1.start();
+    float peakToPeak=0, signalMax=0, signalMin=1024;
+
+    while (_t1.read()<1) {
+        while (_t.read_ms()<50) {
+            _sample=_pin.read();
+
+            if (_sample<1024) {
+                if (_sample>signalMax)
+                    signalMax=_sample;
+
+                else if (_sample<signalMin)
+                    signalMin=_sample;
+            }
+        }
+     _t.reset();
+     peakToPeak=signalMax-signalMin;
+     _value= (peakToPeak*3.3);
+     _value = floor(_value * 100) / 100;
+     _sum+=_value;
+     _count++;
+    }
+    _average=_sum/_count;
+    _t1.reset();
+
+    return _average;
+}
+
+float MAX9814::sound_level() {
+
+    _t.start();
+    float peakToPeak=0, signalMax=0, signalMin=1024;
+
+    while (_t.read_ms()<50) {
+        _sample=_pin.read();
+
+        if (_sample<1024) {
+            if (_sample>signalMax)
+                signalMax=_sample;
+
+            else if (_sample<signalMin)
+                signalMin=_sample;
+        }
+    }
+    _t.reset();
+    peakToPeak=signalMax-signalMin;
+    _value= (peakToPeak*3.3);
+    _value = floor(_value * 100) / 100;
+    _sum+=_value;
+    _count++;
+
+    return _value;
+}
+
+
+void MAX9814::volume_indicator() {
+        led_array(_average);
+        sound_level();
+}