SafeDetect / Mbed OS lora_from_scratch

lora's drivers taken out of examples repo to make a smaller binary

Dependencies:   libxDot-mbed5

src/main.cpp@0:973a5bbb2a17, 2019-11-21 (annotated)

Committer:
guoxsharon
Date:
Thu Nov 21 08:46:20 2019 +0000
Revision:
0:973a5bbb2a17
Child:
1:80bc4501abc5
Sharon_microphone1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
guoxsharon 0:973a5bbb2a17 1
guoxsharon 0:973a5bbb2a17 2 #include "mbed.h"
guoxsharon 0:973a5bbb2a17 3 #define u16_max 65526
guoxsharon 0:973a5bbb2a17 4 AnalogIn mic(PB_0);
guoxsharon 0:973a5bbb2a17 5 DigitalOut vcc(GPIO0);
guoxsharon 0:973a5bbb2a17 6 Serial pc(UART_TX, UART_RX, 115200);
guoxsharon 0:973a5bbb2a17 7 const int sampleTime = 50;
guoxsharon 0:973a5bbb2a17 8 int micOut;
guoxsharon 0:973a5bbb2a17 9 // Find the Peak-to-Peak Amplitude Function
guoxsharon 0:973a5bbb2a17 10 int findPTPAmp(float* sampleArr){
guoxsharon 0:973a5bbb2a17 11 // Time variables to find the peak-to-peak amplitude
guoxsharon 0:973a5bbb2a17 12
guoxsharon 0:973a5bbb2a17 13 unsigned int PTPAmp = 0;
guoxsharon 0:973a5bbb2a17 14
guoxsharon 0:973a5bbb2a17 15 // Signal variables to find the peak-to-peak amplitude
guoxsharon 0:973a5bbb2a17 16 unsigned int maxAmp = 0;
guoxsharon 0:973a5bbb2a17 17 unsigned int minAmp = 1023;
guoxsharon 0:973a5bbb2a17 18
guoxsharon 0:973a5bbb2a17 19 // Find the max and min of the mic output within the 50 ms timeframe
guoxsharon 0:973a5bbb2a17 20 for(int i=0; i<8000; i++)
guoxsharon 0:973a5bbb2a17 21 {
guoxsharon 0:973a5bbb2a17 22 if( sampleArr[i] < 1023) //prevent erroneous readings
guoxsharon 0:973a5bbb2a17 23 {
guoxsharon 0:973a5bbb2a17 24 if (sampleArr[i] > maxAmp)
guoxsharon 0:973a5bbb2a17 25 {
guoxsharon 0:973a5bbb2a17 26 maxAmp = sampleArr[i]; //save only the max reading
guoxsharon 0:973a5bbb2a17 27 }
guoxsharon 0:973a5bbb2a17 28 else if (sampleArr[i] < minAmp)
guoxsharon 0:973a5bbb2a17 29 {
guoxsharon 0:973a5bbb2a17 30 minAmp = sampleArr[i]; //save only the min reading
guoxsharon 0:973a5bbb2a17 31 }
guoxsharon 0:973a5bbb2a17 32 }
guoxsharon 0:973a5bbb2a17 33 }
guoxsharon 0:973a5bbb2a17 34
guoxsharon 0:973a5bbb2a17 35 PTPAmp = maxAmp - minAmp; // (max amp) - (min amp) = peak-to-peak amplitude
guoxsharon 0:973a5bbb2a17 36 double micOut_Volts = (PTPAmp * 3.3) / 1024; // Convert ADC into voltage
guoxsharon 0:973a5bbb2a17 37
guoxsharon 0:973a5bbb2a17 38 //Uncomment this line for help debugging (be sure to also comment out the VUMeter function)
guoxsharon 0:973a5bbb2a17 39 //Serial.println(PTPAmp);
guoxsharon 0:973a5bbb2a17 40
guoxsharon 0:973a5bbb2a17 41 //Return the PTP amplitude to use in the soundLevel function.
guoxsharon 0:973a5bbb2a17 42 // You can also return the micOut_Volts if you prefer to use the voltage level.
guoxsharon 0:973a5bbb2a17 43 return PTPAmp;
guoxsharon 0:973a5bbb2a17 44 }
guoxsharon 0:973a5bbb2a17 45
guoxsharon 0:973a5bbb2a17 46 void record(float* sampleArr) {
guoxsharon 0:973a5bbb2a17 47 //record sound for 1 second
guoxsharon 0:973a5bbb2a17 48 for(int i=0; i<8000; i++) {
guoxsharon 0:973a5bbb2a17 49 sampleArr[i] = mic.read(); //put samples in array
guoxsharon 0:973a5bbb2a17 50 wait(0.000125f); //sample rate of 8000 Hz
guoxsharon 0:973a5bbb2a17 51 }
guoxsharon 0:973a5bbb2a17 52 }
guoxsharon 0:973a5bbb2a17 53
guoxsharon 0:973a5bbb2a17 54 int main(){
guoxsharon 0:973a5bbb2a17 55 float sampleArr[8000]; //used to store sound
guoxsharon 0:973a5bbb2a17 56 pc.printf("\r\n Sparkfun MEM Microphone Test\n");
guoxsharon 0:973a5bbb2a17 57 pc.printf("******************\n");
guoxsharon 0:973a5bbb2a17 58 vcc = 1;
guoxsharon 0:973a5bbb2a17 59 unsigned int val;
guoxsharon 0:973a5bbb2a17 60 int ptpAmp;
guoxsharon 0:973a5bbb2a17 61 while(1){
guoxsharon 0:973a5bbb2a17 62 wait(0.2);
guoxsharon 0:973a5bbb2a17 63 record(sampleArr);
guoxsharon 0:973a5bbb2a17 64 ptpAmp=findPTPAmp(sampleArr);
guoxsharon 0:973a5bbb2a17 65 }
guoxsharon 0:973a5bbb2a17 66 }
guoxsharon 0:973a5bbb2a17 67
guoxsharon 0:973a5bbb2a17 68
guoxsharon 0:973a5bbb2a17 69