Difference between revisions of "STM32 LED Pulse"

Revision as of 05:07, 23 March 2021

Imagine you had the requirement to turn on a LED for a specific length of time at the press of a button.

Obviously, responding to a button press could be easily handled by an external interrupt, so one could come up with something like:

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
    if (GPIO_Pin == BTN_Pin) // If the button
    {

        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET); // Switch LED ON
        HAL_Delay(500); // Wait 500 ms
        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET); // Switch LED OFF

    }
}

It should be equally obvious why this is a really piss poor idea. The function will block for half a second, leaving the processor unable to do anything else for that period.

A much better idea.

Difference between revisions of "STM32 LED Pulse"

Revision as of 05:07, 23 March 2021

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@@ Line 1: / Line 1: @@
 [[Category:C]] [[Category:STM32 Development]] [[Category:STM32CubeMX]] [[Category:STM32CubeIde]] [[Category:Embedded]] [[Category:STM32]] {{metadesc|Pulse a LED using STM32}}
-xxx
+Imagine you had the requirement to turn on a [[LED]] for a specific length of time at the press of a button.
+Obviously, responding to a button press could be easily handled by an external interrupt, so one could come up with something like:
+<pre>
+void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
+    if (GPIO_Pin == BTN_Pin) // If the button
+    {
+        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET); // Switch LED ON
+        HAL_Delay(500); // Wait 500 ms
+        HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_SET); // Switch LED OFF
+    }
+}
+</pre>
+It should be equally obvious why this is a really piss poor idea.  The function will block for half a second, leaving the processor unable to do anything else for that period.
+A '''much''' better idea.