Jaydeep Shah / Mbed OS 10) SEMAPHORE_PART1

SEMAPHORE PART-1 USE OF WAIT_UNTIL() FUNCTION , TIME BASED LOCKING + SEMAPHORE SIGNAL BASED LOCKING IMPLEMENTATION SEMAPHORE BASIC PART 1 USE AND APK JAYDEEP SHAH--radhey04ec@gmail.com

main.cpp@1:e0e8a1a599d9, 2020-07-12 (annotated)

Committer:
radhey04ec
Date:
Sun Jul 12 07:58:34 2020 +0000
Revision:
1:e0e8a1a599d9
Parent:
0:a8abf59930e4 
FINAL COMMIT OF SEMAPHORE PART1; WAIT_UNTIL() USE; ;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
radhey04ec 1:e0e8a1a599d9 1 /*SEMAPHORE PART 1
radhey04ec 1:e0e8a1a599d9 2 USE OF WAIT_UNTIL() FUNCTIONS IN SEMAPHORE
radhey04ec 1:e0e8a1a599d9 3 TIME BASED LOCKING + SEMAPHORE SIGNAL BASED LOCKING
radhey04ec 1:e0e8a1a599d9 4 THIS PROGRAM IS FOR CLEARING CONCEPT OF TIME BASED SIGNALING OF SEMAPHORE
radhey04ec 1:e0e8a1a599d9 5 */
radhey04ec 0:a8abf59930e4 6
radhey04ec 0:a8abf59930e4 7 //USE SERIAL TERMINAL WITH 9600 BAUD RATE 8-N-1 FORMAT
radhey04ec 0:a8abf59930e4 8
radhey04ec 0:a8abf59930e4 9 //Created by : JAYDEEP SHAH --radhey04ec@gmail.com
radhey04ec 0:a8abf59930e4 10
radhey04ec 0:a8abf59930e4 11
radhey04ec 0:a8abf59930e4 12 //Library Added :::::
radhey04ec 0:a8abf59930e4 13 #include "mbed.h"
radhey04ec 0:a8abf59930e4 14
radhey04ec 0:a8abf59930e4 15 DigitalOut led(LED1); // ON BOARD LED
radhey04ec 0:a8abf59930e4 16 InterruptIn btn(USER_BUTTON); // ON BOARD BUTTON PORT PC_13
radhey04ec 0:a8abf59930e4 17 //INTERRUPT REGISTERATION
radhey04ec 0:a8abf59930e4 18
radhey04ec 0:a8abf59930e4 19 Semaphore updates(0); //SEMAPHORE OBJECT CREATE = SHARE RESOURCE 0
radhey04ec 0:a8abf59930e4 20 //NO SHARE RESOURCE ONLY ISR
radhey04ec 0:a8abf59930e4 21
radhey04ec 0:a8abf59930e4 22 void do_something() { //ISR FUNCTION
radhey04ec 0:a8abf59930e4 23 // release the semaphore
radhey04ec 0:a8abf59930e4 24 updates.release(); // NOW V=1
radhey04ec 0:a8abf59930e4 25 }
radhey04ec 0:a8abf59930e4 26
radhey04ec 0:a8abf59930e4 27 int main() {
radhey04ec 0:a8abf59930e4 28 btn.fall(&do_something); //FUNCTION CALL WHEN FALL EDGE OF BUTTON - ISR
radhey04ec 0:a8abf59930e4 29
radhey04ec 0:a8abf59930e4 30 while (1) { //LOOP FOREVER
radhey04ec 0:a8abf59930e4 31 // wait for the semaphore to be released from the ISR
radhey04ec 0:a8abf59930e4 32 uint32_t v = updates.wait_until(30000); //RETURN STORE IN V
radhey04ec 0:a8abf59930e4 33
radhey04ec 0:a8abf59930e4 34 // now this runs on the main thread, and is safe
radhey04ec 0:a8abf59930e4 35
radhey04ec 0:a8abf59930e4 36 if(v==1) //THIS ONLY RUN WHEN BUTTON PRESS & SEMAPHORE RELEASE BY 1
radhey04ec 0:a8abf59930e4 37 {
radhey04ec 0:a8abf59930e4 38 led = !led; //LED TOGGLE
radhey04ec 0:a8abf59930e4 39 printf("Toggle LED! V= %d \r\n",v); //SERIAL PRINT V === 0 AGAIN
radhey04ec 0:a8abf59930e4 40 }
radhey04ec 0:a8abf59930e4 41
radhey04ec 0:a8abf59930e4 42 if(v == 0) // This Function run after 30 sec of Power on/RST Continue -- NO matter button press or not
radhey04ec 0:a8abf59930e4 43 {
radhey04ec 0:a8abf59930e4 44 printf("\n TIMER RELEASE SEMAPHORE V = %d \r\n",v);
radhey04ec 0:a8abf59930e4 45 }
radhey04ec 0:a8abf59930e4 46
radhey04ec 0:a8abf59930e4 47 }
radhey04ec 0:a8abf59930e4 48 }