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
Diff: Hammer_MicrophoneSensor.cpp
- 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();
+}
Andrea Corrado
Electret Microphone Amplifier - MAX9814