Diff: main.cpp

Revision:

0:a8abf59930e4

Child:

1:e0e8a1a599d9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Jul 12 07:53:33 2020 +0000
@@ -0,0 +1,52 @@
+//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);  //FUNCTION CALL WHEN FALL EDGE OF BUTTON - ISR
+
+  while (1) {  //LOOP FOREVER
+    // wait for the semaphore to be released from the ISR
+    uint32_t v = updates.wait_until(30000);    //RETURN STORE IN V
+
+    // now this runs on the main thread, and is safe
+
+    if(v==1)  //THIS ONLY RUN WHEN BUTTON PRESS & SEMAPHORE RELEASE BY 1
+{
+      led = !led;    //LED TOGGLE
+      printf("Toggle LED! V= %d \r\n",v);  //SERIAL PRINT  V  === 0 AGAIN
+    }
+    
+    if(v == 0)  // This Function run after 30 sec of Power on/RST Continue   -- NO matter button press or not
+    {
+    printf("\n TIMER RELEASE SEMAPHORE V = %d \r\n",v);
+  }
+  
+  }
+}
\ No newline at end of file