global-state-experiment

This project helped me to answer the question how to share a GPIO pin across different threads. There are two branches:

• FreeRTOS-Threads here the threads are created using EP-IDF FreeRTOS
• master here the threads are created using embassy-sync. This version doesn't work as expected as the Timer function doesn't behave like expected. It looks like that after a while the timer doesn't create the specified delay.

How does the sharing work?

In the main thread the shared GPIO pin is stored in

type LedPin = esp_idf_hal::gpio::PinDriver<'static, Gpio7, Output>;

static LED_PIN: static_cell::StaticCell<Arc<Mutex<EspRawMutex, RefCell<LedPin>>>> = 
    static_cell::StaticCell::new();

which provides a thread safe way to handle access to the shared GPIO pin

How to build?

The project is targeting the esp-rust-board which uses a esp32c3 SoC. The led pin used is GPIO7.

cargo espflash flash --monitor --port /dev/ttyACM0  

The project creates two threads. One thread sets the led pin to high, the other thread sets the pin to low. Both threads have different delay/sleep values. The result is a blinking led.