Diff: main.cpp

Revision:

0:090c812cb33b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jul 12 06:35:41 2020 +0000
@@ -0,0 +1,46 @@
+//USE OF PRINTF() STATEMENT IN MBED  WITH ISR
+
+//method : semaphore 
+
+/* NOTE : PRINTF() IS PART OF STDIO.H LIBRARY
+AND THIS LIBRARY PROTECTED BY MUTEX GUARD, SO YOU CAN NOT CALL PRINTF() FROM
+ISR FUNCTION.
+SIMPLE WAY IS USE SOMETYPE OF SIGNAL OR FLAG AND PRINTF() OUTSIDE ISR depends on 
+flag and signal  */
+
+//USE SERIAL TERMINAL WITH 9600 BAUD RATE  8-N-1 FORMAT
+
+//Created by : JAYDEEP SHAH  --radhey04ec@gmail.com
+
+
+//Library Added :::::
+#include "mbed.h"
+
+DigitalOut led(LED1);  // ON BOARD LED
+InterruptIn btn(USER_BUTTON);  // ON BOARD BUTTON  PORT PC_13 
+//INTERRUPT REGISTERATION
+
+Semaphore updates(0);  //SEMAPHORE OBJECT CREATE = SHARE RESOURCE 0
+//NO SHARE RESOURCE ONLY ISR
+
+void do_something() {        //ISR FUNCTION
+  // release the semaphore
+  updates.release();   // NOW V=1
+}
+
+int main() {
+  btn.fall(&do_something);
+
+  while (1) {
+    // wait for the semaphore to be released from the ISR
+    uint32_t v = updates.wait();    //RETURN STORE IN V
+
+    // now this runs on the main thread, and is safe
+    if(v == 1)
+    
+{
+      led = !led;    //LED TOGGLE
+      printf("Toggle LED!\r\n");  //SERIAL PRINT
+    }
+  }
+}
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