Diff: main.cpp

Revision:

0:8dd765fb7e02

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Mar 09 06:57:34 2018 +0000
@@ -0,0 +1,40 @@
+#include "mbed.h"
+#include "math.h"
+
+// Measure duration of time that the signal is low in a 30sec period.
+
+InterruptIn input(PA_0); // Change your pin name here
+Timer t;    // measure amount of time signal is low
+Ticker m;   // every 30 seconds calculate measurement
+
+// Start Timer
+void start(void){
+    t.start();
+}
+
+// Stop TImer
+void stop(void){
+    t.stop();
+}
+
+// calculate sensor value
+void calculate(){
+    // run measurements
+    int lpo = t.read_us();
+    float ratio = t.read_us()/(30000*10.0);
+    float concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62;
+    printf("\r\nlpo = %d, r = %f, c = %f pcs/0.01cf\r\n",lpo,ratio,concentration);
+    
+    // reset and run sensors
+    t.reset(); // reset mesurement every 30 seconds
+    input.fall(&start); // start measuring when signal is low
+    input.rise(&stop);  // stop measuring when signal is high
+}
+
+int main(){
+    printf("\r\n Starting...\r\n");
+    m.attach(&calculate,30.0); // measure for 30 seconds
+    while(1){
+        ;
+    }
+}
\ No newline at end of file