Daniel Worrall
Measure the time interval between two consecutive rising edges
Dependencies: dispBoB mbed PCA9635
intervalMeasure.cpp@2:62e168aedc9a, 2011-07-12 (annotated)
- Committer:
- d_worrall
- Date:
- Tue Jul 12 10:04:32 2011 +0000
- Revision:
- 2:62e168aedc9a
- Parent:
- 1:b56440e55747
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| d_worrall | 0:37bc70ca825c | 1 | #include "mbed.h" |
| d_worrall | 0:37bc70ca825c | 2 | #include "dispBoB.h" |
| d_worrall | 0:37bc70ca825c | 3 | |
| d_worrall | 0:37bc70ca825c | 4 | dispBoB db(p28, p27, p26); //instantiate a dispBoB object |
| d_worrall | 0:37bc70ca825c | 5 | InterruptIn trigger(p12); //set up the trigger as an external interrupt |
| d_worrall | 0:37bc70ca825c | 6 | Timer t; |
| d_worrall | 0:37bc70ca825c | 7 | |
| d_worrall | 0:37bc70ca825c | 8 | bool b = false; |
| d_worrall | 0:37bc70ca825c | 9 | |
| d_worrall | 1:b56440e55747 | 10 | void trig(){ //function to call upon interrupt |
| d_worrall | 0:37bc70ca825c | 11 | db.locate(0); |
| d_worrall | 1:b56440e55747 | 12 | db.printf("%06d", t.read_ms()); //print current time reading |
| d_worrall | 0:37bc70ca825c | 13 | if(b == false){ |
| d_worrall | 1:b56440e55747 | 14 | t.start(); //start timer |
| d_worrall | 0:37bc70ca825c | 15 | b = true; |
| d_worrall | 0:37bc70ca825c | 16 | } else { |
| d_worrall | 1:b56440e55747 | 17 | t.stop(); //stop timer |
| d_worrall | 1:b56440e55747 | 18 | db.printf("06d", t.read_ms()); //print out stopwatch time in milliseconds |
| d_worrall | 1:b56440e55747 | 19 | t.reset(); //reset and restart timer |
| d_worrall | 0:37bc70ca825c | 20 | t.start(); |
| d_worrall | 0:37bc70ca825c | 21 | } |
| d_worrall | 0:37bc70ca825c | 22 | } |
| d_worrall | 0:37bc70ca825c | 23 | |
| d_worrall | 0:37bc70ca825c | 24 | int main() { |
| d_worrall | 0:37bc70ca825c | 25 | trigger.mode(PullUp); //activate internal pull up (hardware specific) |
| d_worrall | 1:b56440e55747 | 26 | db.init(); //ALWAYS initialise the dispBoB |
| d_worrall | 2:62e168aedc9a | 27 | db.cls(); |
| d_worrall | 2:62e168aedc9a | 28 | trigger.rise(&trig); //attach trig() to interrupt on rising edge of trigger |
| d_worrall | 0:37bc70ca825c | 29 | |
| d_worrall | 1:b56440e55747 | 30 | db.printf("%06d", t.read_ms()); //print initial time reading (000000) |
| d_worrall | 0:37bc70ca825c | 31 | |
| d_worrall | 2:62e168aedc9a | 32 | //To change the timebase just replace the read_ms() function with |
| d_worrall | 2:62e168aedc9a | 33 | //read() for seconds and read_us() for microseconds. These use a 32bit |
| d_worrall | 2:62e168aedc9a | 34 | //int microsecond counter, so have a max time of ~30mins |
| d_worrall | 0:37bc70ca825c | 35 | } |