If anyone ever encounters something while developing on this project that makes you think "wow, I really wish I had known that beforehand" or "man, I hope nobody has to debug an error as stupid as that again", write it here! There's not point in struggling with the same bug twice. This document is meant to be a compilation of many of such issues. Even if it's unlikely that anyone else will encounter it (e.g. specific to environment), it can be useful just for your own sake.
- Do not dynamically allocate memory/arrays inside tasks
- This will mess with execution flow and cause tasks to fail
- If you really need to there are special functions to do so
- For example, do not do either of the following inside the task:
int arr[20];
int* arr = (int*) malloc(20 * sizeof(int));-
Stack size
- If your program seems to be working up until you add a seemingly innocent line, you're stack size might be too low
- To fix this change the stack size parameter when creating the task
-
Tasks cannot end!
- FreeRTOS has separation anxiety and is not comfortable with tasks ending unannounced. It may block and act strangely.
- If a task is going to end, I think you can avert this issue with
vTaskSuspend(NULL)at the end of the task.
- Don't forget to flush the buffer for things to be printed
- For example having a "blink" sketch repeatedly running the first following line will yield no result!
- This sounds obvious (and indeed it is) but it's very easy to forget
printf("Hello World"); // Bad
printf("Hello World\n"); // Good