mbed school / Mbed 2 deprecated ch5_mbed_dust_sensor

ch5_mbed_dust_sensor

Dependencies:   mbed

Diff: main.cpp

Revision:
0:859e0fd616ee
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jan 26 09:10:53 2015 +0000
@@ -0,0 +1,44 @@
+#include "mbed.h"
+ 
+Serial pc(USBTX, USBRX);
+InterruptIn probe(p19);
+DigitalOut led(LED1);
+
+Timer timer;
+Ticker ticker;
+
+uint32_t low_time = 0;
+
+void down();
+void up();
+
+void tick()
+{
+    pc.printf("%d us, %f %%\r\n", low_time, low_time / (30.0 * 1000000));
+    low_time = 0;
+}
+ 
+void down()
+{
+    probe.rise(&up);
+    led = 0;
+    timer.start();
+}
+
+void up()
+{
+    led = 1;
+    timer.stop();
+    probe.fall(&down);
+    
+    low_time += timer.read_us();
+    timer.reset();
+}
+ 
+int main()
+{
+    pc.baud(115200);
+    pc.printf("Dust Sensor test\r\n");
+    probe.fall(&down);
+    ticker.attach(tick, 30);    
+}
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