ARM® Cortex® M4 Cookbook

Why we must use a mutex to access the GLCD

How to do it…

To access the GLCD using mutual exclusion, follow the steps outlined:

1. Create a new project and using the manager configure the RTE to provide support for the Graphic LCD.
2. Create a new file named RTXBlinky.c, add the boilerplate code, and then add this source file to the project.
3. Add the following code to RTXBlinky.c:

   #include "stm32f4xx_hal.h" /* STM32F4xx Defs */ #include "RTXBlinkyUtils.h" #include "cmsis_os.h" osThreadId tid_taskA; /* id of thread: task_a */ osThreadId tid_taskB; /* id of thread: task_b */ osMutexId mut_GLCD; /* Mutex to control GLCD access */ /*-------------------------------------------------- * Switch LED on *--------------------------------------------------*/ void switch_On ...