How to Ensure Atomic Access to Queue in ESP32 FreeRTOS Project?
Hey guys so while i was developing an ESP32 IoT project using FreeRTOS, I'm encountering intermittent data corruption when two tasks share a queue for sensor data (readSensorTask: Reads temperature, humidity, and pressure data from sensors (BME280) every 1 second and the processDataTask: Processes the sensor data and sends it to a cloud server (MQTT)
every 10 seconds.) Despite using mutexes, I'm seeing the following error:
Error message:
I was trying to send sensor data to the queue using:
How can I ensure atomic access to the queue and prevent simultaneous writes?
every 10 seconds.) Despite using mutexes, I'm seeing the following error:
Guru Meditation Error: Core 0 panic'ed (LoadProhibited)Error message:
pc 0x400f36d6 ps 0x6000003f (crash log attached)I was trying to send sensor data to the queue using:
How can I ensure atomic access to the queue and prevent simultaneous writes?
Solution
try this approach
- **Check Mutex Usage**: Ensure you're correctly locking and unlocking the mutex when accessing the queue.```cxSemaphoreTake(mutex, portMAX_DELAY);xQueueSend(sensorQueue, &sensorData, portMAX_DELAY);xSemaphoreGive(mutex);```
- Verify Queue Size: Make sure the queue is large enough for the data you're sending.
- **Check Return Values**: Always check the return value of `xQueueSend` for errors:```cif (xQueueSend(sensorQueue, &sensorData, portMAX_DELAY) != pdTRUE) { // Handle error}```
- **Inspect Crash Log**: Look at the crash log for details on where the error occurs.
