Simon Ford
Example to show how priority can be used to ensure timing critical task can be run
Revision 0:2b952ccae54d, committed 2010-08-17
- Comitter:
- simon
- Date:
- Tue Aug 17 10:14:44 2010 +0000
- Commit message:
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 |
diff -r 000000000000 -r 2b952ccae54d main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Tue Aug 17 10:14:44 2010 +0000
@@ -0,0 +1,46 @@
+// Example running the mbed Tickers at a lower priority
+
+#include "mbed.h"
+
+volatile int counter = 0;
+void timing_critical() {
+ counter++;
+}
+
+void long_event() {
+ wait_ms(50);
+}
+
+PwmOut out(p25);
+InterruptIn in(p26);
+Ticker tick;
+
+int main() {
+ out.period_ms(10);
+ out.pulsewidth_ms(5);
+ in.rise(&timing_critical);
+
+ printf("1) InterruptIn only...\n");
+ for(int i=0; i<5; i++) {
+ counter = 0;
+ wait(1);
+ printf("counts/sec = %d\n", counter);
+ }
+
+ tick.attach(&long_event, 0.1);
+
+ printf("2) InterruptIn plus long running occasional ticker event...\n");
+ for(int i=0; i<5; i++) {
+ counter = 0;
+ wait(1);
+ printf("count/sec = %d\n", counter);
+ }
+
+ printf("3) InterruptIn plus long running occasional ticker event at lower priority...\n");
+ NVIC_SetPriority(TIMER3_IRQn, 255); // set mbed tickers to lower priority than other things
+ for(int i=0; i<5; i++) {
+ counter = 0;
+ wait(1);
+ printf("counter = %d\n", counter);
+ }
+}
diff -r 000000000000 -r 2b952ccae54d mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Tue Aug 17 10:14:44 2010 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/9114680c05da