Neel Shah
I used the code to read pulses from the Ambient weather air flow meter.
Revision 0:c5bcf643a8b1, committed 2013-02-03
- Comitter:
- Neel
- Date:
- Sun Feb 03 21:06:02 2013 +0000
- Commit message:
- Can read pulses on the pin and convert them into frequency count
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
| mbed.bld | Show annotated file Show diff for this revision Revisions of this file |
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Feb 03 21:06:02 2013 +0000
@@ -0,0 +1,32 @@
+#include "mbed.h"
+
+Serial pc(USBTX, USBRX);
+InterruptIn in(p8);
+DigitalOut led(LED1);
+DigitalOut led2(LED2);
+Timer t1;
+
+float t_period = 0; // This is the period between interrupts in microseconds
+float t_freq = 0;
+
+void flip(void)
+{
+ led=!led;
+ t_period = t1.read_us(); // Get time since last interrupt
+ t_freq = (1/t_period)*1000000; // Convert period (in us) to frequency (Hz)
+ t1.reset(); // Reset timer and wait for next interrupt
+}
+
+int main() {
+ pc.printf("\rStarting frequency counter\n");
+ in.mode(PullDown); // Set the pin to Pull Down mode.
+ in.rise(&flip); // Set up the interrupt for rising edge
+ t1.start(); // start the timer
+
+ while (1) {
+ wait_ms(100);
+ led2=!led2;
+ pc.printf("\rfrq is %d Hz\n", (int)t_freq);
+ }
+
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sun Feb 03 21:06:02 2013 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/cd19af002ccc \ No newline at end of file