Brendon Ky / Mbed 2 deprecated cs_335_speedometer

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Dependencies:   mbed mbed-rtos

main.cpp

Committer:
bky
Date:
2020-12-01
Revision:
10:8d86e59fb408
Parent:
9:b7e8d0372f53
Child:
11:dd860c2e12ec

File content as of revision 10:8d86e59fb408:

# include "mbed.h"
# include "Timer.h"

# include <stdlib.h>
# include <time.h>

# define NUM_HOLES 32
# define CIRCUMFRENCE_CM 48.6946861

# define LIGHT_SENSOR_PIN p15
# define FLASH_THRESHOLD 0.93


AnalogIn lightSensorVoltage(LIGHT_SENSOR_PIN);
Serial pc(USBTX, USBRX);

DigitalOut myled(LED1);

int lastFlash = 0;
float prevVoltReading = 0.0;
float currVoltReading = 0.0;
float rotationsPerMili = 0.0;

void sendFloat(float value) {
    for (int i=0; i<4; i++)
        pc.putc(*(((char*) &value)+i));
}

int main() {
    Timer timer;
    timer.start();
    int currTime = 0;
    int prevTime = 0;
    
    float velocity = 0;
    
    while(1) {
        currVoltReading = lightSensorVoltage.read();
        if(prevVoltReading < FLASH_THRESHOLD && currVoltReading >= FLASH_THRESHOLD) {
            currTime = timer.read_ms();
            rotationsPerMili = (currTime - prevTime) / NUM_HOLES;
            
            prevTime = currTime;
            velocity = CIRCUMFRENCE_CM * rotationsPerMili * 1000;
        }
        
        prevVoltReading = currVoltReading;
        
        sendFloat(velocity);
        wait(0.05);
    }
}