stephen mathenge / Mbed OS final-water-level_2

How to measure water in a reservoir

Dependencies:   Cayenne-MQTT-mbed Cayenne-LPP

inc/dust_sensor.h@0:7bfeb237e600, 2019-03-08 (annotated)

Committer:
wamae
Date:
Fri Mar 08 11:34:56 2019 +0000
Revision:
0:7bfeb237e600
working code

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wamae 0:7bfeb237e600 1 #ifndef _DUST_SENSOR_H
wamae 0:7bfeb237e600 2 #define _DUST_SENSOR_H
wamae 0:7bfeb237e600 3
wamae 0:7bfeb237e600 4 #include "mbed.h"
wamae 0:7bfeb237e600 5
wamae 0:7bfeb237e600 6 class DustSensor : public NonCopyable<DustSensor> {
wamae 0:7bfeb237e600 7 public:
wamae 0:7bfeb237e600 8 DustSensor(PinName pin) : _input(pin), _cb(NULL), _busy(false) {
wamae 0:7bfeb237e600 9
wamae 0:7bfeb237e600 10 }
wamae 0:7bfeb237e600 11
wamae 0:7bfeb237e600 12 bool measure(Callback<void(int, float, float)> cb) {
wamae 0:7bfeb237e600 13 if (_busy) {
wamae 0:7bfeb237e600 14 return false;
wamae 0:7bfeb237e600 15 }
wamae 0:7bfeb237e600 16
wamae 0:7bfeb237e600 17 _cb = cb;
wamae 0:7bfeb237e600 18
wamae 0:7bfeb237e600 19 _busy = true;
wamae 0:7bfeb237e600 20
wamae 0:7bfeb237e600 21 m.attach(callback(this, &DustSensor::calculate), 30.0f);
wamae 0:7bfeb237e600 22 t.reset(); // reset mesurement every 30 seconds
wamae 0:7bfeb237e600 23 _input.fall(callback(this, &DustSensor::start)); // start measuring when signal is low
wamae 0:7bfeb237e600 24 _input.rise(callback(this, &DustSensor::stop)); // stop measuring when signal is high
wamae 0:7bfeb237e600 25
wamae 0:7bfeb237e600 26 return true;
wamae 0:7bfeb237e600 27 }
wamae 0:7bfeb237e600 28
wamae 0:7bfeb237e600 29 bool is_busy() {
wamae 0:7bfeb237e600 30 return _busy;
wamae 0:7bfeb237e600 31 }
wamae 0:7bfeb237e600 32
wamae 0:7bfeb237e600 33 private:
wamae 0:7bfeb237e600 34 // Start Timer
wamae 0:7bfeb237e600 35 void start(void) {
wamae 0:7bfeb237e600 36 t.start();
wamae 0:7bfeb237e600 37 }
wamae 0:7bfeb237e600 38
wamae 0:7bfeb237e600 39 // Stop Timer
wamae 0:7bfeb237e600 40 void stop(void) {
wamae 0:7bfeb237e600 41 t.stop();
wamae 0:7bfeb237e600 42 }
wamae 0:7bfeb237e600 43
wamae 0:7bfeb237e600 44 // calculate sensor value
wamae 0:7bfeb237e600 45 void calculate() {
wamae 0:7bfeb237e600 46 // run measurements
wamae 0:7bfeb237e600 47 int lpo = t.read_us();
wamae 0:7bfeb237e600 48 float ratio = t.read_us() / (30000 * 10.0);
wamae 0:7bfeb237e600 49 float concentration = 1.1 * pow(ratio,3) -3.8 * pow(ratio, 2) + 520 * ratio + 0.62;
wamae 0:7bfeb237e600 50 _cb(lpo, ratio, concentration);
wamae 0:7bfeb237e600 51
wamae 0:7bfeb237e600 52 _busy = false;
wamae 0:7bfeb237e600 53 }
wamae 0:7bfeb237e600 54
wamae 0:7bfeb237e600 55 InterruptIn _input;
wamae 0:7bfeb237e600 56 Callback<void(int, float, float)> _cb;
wamae 0:7bfeb237e600 57
wamae 0:7bfeb237e600 58 bool _busy;
wamae 0:7bfeb237e600 59
wamae 0:7bfeb237e600 60 Timer t; // measure amount of time signal is low
wamae 0:7bfeb237e600 61 Timeout m; // every 30 seconds calculate measurement
wamae 0:7bfeb237e600 62 };
wamae 0:7bfeb237e600 63
wamae 0:7bfeb237e600 64 #endif // _DUST_SENSOR_H