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Diff: main.cpp
- Revision:
- 1:18e0f8aef32f
- Parent:
- 0:5307f49cd305
- Child:
- 2:e27fd3b65155
diff -r 5307f49cd305 -r 18e0f8aef32f main.cpp
--- a/main.cpp Wed Feb 01 13:38:02 2017 +0000
+++ b/main.cpp Wed Feb 01 13:53:26 2017 +0000
@@ -3,7 +3,7 @@
// Periodically write to the AnalogOut to create a sine wave
// Alternate between two fixed frequencies every 5 sec
//
-// THIS VERSION HAS DEBUGGING CODE USING THE SERIAL PORT
+// THIS VERSION HAS NO DEBUGGING CODE
#include "mbed.h"
#include "rtos.h"
@@ -12,51 +12,24 @@
Ticker tick ; // Creates periodic interrupt
AnalogOut ao(PTE30) ; // Analog output
-// --- following code for debugging ---
-Thread debugT ;
-Serial pc(USBTX, USBRX); // tx, rx, useful for debugging
-
-// Put a simple reprsentation of the sine wave
-// to the serial output. ONLY at low frequency
-void debug(int index) {
- int sine4 = sine[index] >> 11 ; // get top 5 bits
- pc.putc('*') ;
- while (sine4--) pc.putc('*') ;
- pc.putc('\n') ;
- //pc.putc('\r') ;
-}
-
+// Function called periodically
+// Write new value to AnalogOut
volatile int index = 0 ; // this variable is not just for debugging!!
-
-void debugCallback() {
- while (true) {
- Thread::signal_wait(0x1) ;
- debug(index) ; // there is a race condition here
- }
-}
-// ---- end of debugging code ---------
-
-// Function called every periodically
-// Write new value to AnalogOut
void writeAout() {
ao.write_u16(sine[index]) ;
- debugT.signal_set(0x1) ; // DEBUGGING low frequency only
index = (index + 1) % 64 ;
}
// Control the frequency of updates
// Alternative between two frequencies
int main() {
- int update_us = 100000 ; // 100ms
- debugT.start(&debugCallback) ;
+ int update_us = 1000 ; // 1ms
while (true) {
- pc.printf("Update at 64 x 100ms giving about 0.15Hz\n");
tick.attach_us(callback(&writeAout), update_us); // setup ticker to write to AnalogOut
Thread::wait(30000) ; // wait 30 sec - 30000ms
- update_us = 150000 ; // 150ms
- pc.printf("Update at 64 x 150ms giving about 0.1Hz\n");
+ update_us = 2000 ; // 2ms
tick.attach_us(callback(&writeAout), update_us); // setup ticker to write to AnalogOut
Thread::wait(30000) ; // wait 30 sec - 30000ms
- update_us = 100000 ; // 100ms
+ update_us = 1000 ; // 1ms
}
}
