Daniel Worrall
Measure the width (time-wise) of an incoming pulse.
Dependencies: dispBoB mbed PCA9635
counter.cpp@2:bb7e46464d17, 2011-07-12 (annotated)
- Committer:
- d_worrall
- Date:
- Tue Jul 12 10:05:44 2011 +0000
- Revision:
- 2:bb7e46464d17
- Parent:
- 1:f04131cae8b8
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| d_worrall | 0:dd684fb95312 | 1 | #include "mbed.h" |
| d_worrall | 0:dd684fb95312 | 2 | #include "dispBoB.h" |
| d_worrall | 0:dd684fb95312 | 3 | |
| d_worrall | 0:dd684fb95312 | 4 | dispBoB db(p28, p27, p26); //instantiate a dispBoB object |
| d_worrall | 0:dd684fb95312 | 5 | InterruptIn trigger(p12); //set up the trigger as an external interrupt |
| d_worrall | 0:dd684fb95312 | 6 | Timer t; |
| d_worrall | 0:dd684fb95312 | 7 | |
| d_worrall | 1:f04131cae8b8 | 8 | void up(){ //call this on rising edge |
| d_worrall | 1:f04131cae8b8 | 9 | t.start(); //start timer |
| d_worrall | 0:dd684fb95312 | 10 | } |
| d_worrall | 0:dd684fb95312 | 11 | |
| d_worrall | 1:f04131cae8b8 | 12 | void down(){ //call this upon falling edge |
| d_worrall | 1:f04131cae8b8 | 13 | t.stop(); //stop timer |
| d_worrall | 0:dd684fb95312 | 14 | db.locate(0); |
| d_worrall | 2:bb7e46464d17 | 15 | db.printf("%06d", t.read_ms()); //print counter info to dispBoB |
| d_worrall | 1:f04131cae8b8 | 16 | t.reset(); //reset timer |
| d_worrall | 0:dd684fb95312 | 17 | } |
| d_worrall | 0:dd684fb95312 | 18 | |
| d_worrall | 0:dd684fb95312 | 19 | int main() { |
| d_worrall | 0:dd684fb95312 | 20 | trigger.mode(PullUp); //activate internal pull up (hardware specific) |
| d_worrall | 2:bb7e46464d17 | 21 | db.init(); //ALWAYS initialise dispBoB |
| d_worrall | 2:bb7e46464d17 | 22 | db.cls(); |
| d_worrall | 1:f04131cae8b8 | 23 | trigger.rise(&up); //attach up() to interrupt on rising edge of trigger |
| d_worrall | 1:f04131cae8b8 | 24 | trigger.fall(&down); //attach down() to interrupt on falling edge of trigger |
| d_worrall | 2:bb7e46464d17 | 25 | db.printf("%06d", t.read_ms()); //display an initial count "000000" |
| d_worrall | 2:bb7e46464d17 | 26 | |
| d_worrall | 2:bb7e46464d17 | 27 | //To change the timebase just replace the read_ms() function with |
| d_worrall | 2:bb7e46464d17 | 28 | //read() for seconds and read_us() for microseconds. These use a 32bit |
| d_worrall | 2:bb7e46464d17 | 29 | //int microsecond counter, so have a max time of ~30mins |
| d_worrall | 0:dd684fb95312 | 30 | } |