jakob hz / Mbed 2 deprecated HC-SR04-2410

A program that demonstrates the development of library, using as an example an ultrasonic distance sensor HC-SR04.

Dependencies:   mbed HCSR04 AutomationElements

main.cpp@5:889566fb3a85, 2015-12-07 (annotated)

Committer:
tbjazic
Date:
Mon Dec 07 11:45:44 2015 +0000
Revision:
5:889566fb3a85
Parent:
4:052ac3f5c938 
Example of filtering the distance with PT1 filter.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tbjazic 0:ebee649c5b1b 1 #include "mbed.h"
tbjazic 2:f86b1e3609b3 2 #include "HCSR04.h"
tbjazic 4:052ac3f5c938 3 #include "AutomationElements.h"
tbjazic 0:ebee649c5b1b 4
tbjazic 3:3297ea6e3ae1 5 Serial pc(USBTX, USBRX);
tbjazic 4:052ac3f5c938 6 HCSR04 sensor(p5, p7);
tbjazic 4:052ac3f5c938 7 float sampleTime = 0.1;
tbjazic 5:889566fb3a85 8 PT1 filter(1, 2, sampleTime); // filter with a time constant of 2 seconds
tbjazic 5:889566fb3a85 9 float distance = 0;
tbjazic 5:889566fb3a85 10 float filteredDistance = 0;
tbjazic 5:889566fb3a85 11 Timer timer;
tbjazic 4:052ac3f5c938 12
tbjazic 5:889566fb3a85 13 int main() {
tbjazic 5:889566fb3a85 14 sensor.setRanges(4, 400);
tbjazic 5:889566fb3a85 15 pc.printf("Minimum sensor range = %g cm\n\rMaximum sensor range = %g cm\n\r", sensor.getMinRange(), sensor.getMaxRange());
tbjazic 5:889566fb3a85 16 pc.printf("Sensor: Filtered:\n\r");
tbjazic 5:889566fb3a85 17
tbjazic 5:889566fb3a85 18 timer.start();
tbjazic 4:052ac3f5c938 19 distance = sensor.getDistance_mm();
tbjazic 5:889566fb3a85 20 timer.stop();
tbjazic 5:889566fb3a85 21 int time1 = timer.read_us();
tbjazic 5:889566fb3a85 22 pc.printf("Time to get distance: %d us \n\r", time1);
tbjazic 5:889566fb3a85 23 timer.reset();
tbjazic 5:889566fb3a85 24
tbjazic 5:889566fb3a85 25 timer.start();
tbjazic 4:052ac3f5c938 26 filter.in(distance);
tbjazic 4:052ac3f5c938 27 filteredDistance = filter.out();
tbjazic 5:889566fb3a85 28 timer.stop();
tbjazic 5:889566fb3a85 29 int time2 = timer.read_us();
tbjazic 5:889566fb3a85 30 pc.printf("Time to filter result: %d us \n\r", time2);
tbjazic 5:889566fb3a85 31 timer.reset();
tbjazic 5:889566fb3a85 32
tbjazic 5:889566fb3a85 33 timer.start();
tbjazic 4:052ac3f5c938 34 pc.printf("%7.1f mm %7.1f mm \r", distance, filteredDistance);
tbjazic 5:889566fb3a85 35 timer.stop();
tbjazic 5:889566fb3a85 36 int time3 = timer.read_us();
tbjazic 5:889566fb3a85 37 pc.printf("Time to printf one line: %d us \n\r", time3);
tbjazic 5:889566fb3a85 38 timer.reset();
tbjazic 5:889566fb3a85 39
tbjazic 4:052ac3f5c938 40 pc.printf("Sensor: Filtered:\n\r");
tbjazic 4:052ac3f5c938 41
tbjazic 0:ebee649c5b1b 42 while(1) {
tbjazic 5:889566fb3a85 43 distance = sensor.getDistance_mm();
tbjazic 5:889566fb3a85 44 filter.in(distance);
tbjazic 5:889566fb3a85 45 filteredDistance = filter.out();
tbjazic 5:889566fb3a85 46 pc.printf("%7.1f mm %7.1f mm \r", distance, filteredDistance);
tbjazic 5:889566fb3a85 47 wait_us(sampleTime*1e6 - time1 - time2 - time3);
tbjazic 0:ebee649c5b1b 48 }
tbjazic 0:ebee649c5b1b 49 }