TVZ Mechatronics Team / Mbed 2 deprecated HC-SR04

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

Dependencies:   mbed HCSR04 AutomationElements

The purpose of this program is to encourage students to develope their own classes. Instructions how to follow the development of this program and class HCSR04 for ultrasonic distance measurement are given here.

Diff: main.cpp

Revision:
6:bca0839e8295
Parent:
4:052ac3f5c938
--- a/main.cpp	Mon Dec 07 10:44:07 2015 +0000
+++ b/main.cpp	Sat Dec 10 08:28:06 2016 +0000
@@ -4,29 +4,28 @@
 
 Serial pc(USBTX, USBRX);
 HCSR04 sensor(p5, p7);
-float sampleTime = 0.1;
+float sampleTime = 0.5;
 PT1 filter(1, 2, sampleTime);
 Ticker ticker;
 float distance;
 float filteredDistance; 
-DigitalOut led1(LED1);
 
 void calc() {
-    led1 = 1;
-    distance = sensor.getDistance_mm();
-    filter.in(distance);
-    filteredDistance = filter.out();
-    pc.printf("%7.1f mm  %7.1f mm  \r", distance, filteredDistance);
-    led1 = 0;
+    sensor.startMeasurement();
 }
 
 int main() {
-    sensor.setRanges(10, 110);
+    sensor.setRanges(2, 400);
     pc.printf("Minimum sensor range = %g cm\n\rMaximum sensor range = %g cm\n\r", sensor.getMinRange(), sensor.getMaxRange());
     pc.printf("Sensor:       Filtered:\n\r");
     ticker.attach(&calc, sampleTime);
-    
-    while(1) {
-        wait_ms(500);
+    while(true) {
+        while(!sensor.isNewDataReady()) {
+        // wait for new data
+        }
+        distance = sensor.getDistance_cm();
+        filter.in(distance);
+        filteredDistance = filter.out();
+        pc.printf("%7.1f cm  %7.1f cm\n\r", distance, filteredDistance);
     }
 }
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