Controls WS2812B type digital LEDs using the RMT peripheral of ESP32.
This implementation uses the RMT driver from ESP-IDF and uses one RMT channel
for a LED strip leaving the other channels free, under the control of the RMT driver.
Here are some key points of this implementation:
- the control of the LEDs is separated from the control of the
RMTperipheral; - the other
RMTchannels can be used as needed; - the
RMTperipheral is used throughESP-IDF's own driver.
Right now the whole negative point is that this code uses a lot of RAM, because of the way the driver and peripheral works, but this will change if/when the driver will be updated with a hook in transmission code.
Timings are from datasheets. According to Worldsemi's datasheets there are a few timings sets:
- one for WS2812
- one for WS2812B, WS2812C, WS2812S, WS2813 and WS2815
- one for WS2812D
In Tim's Blog (cpldcpu) are some interesting investigations about timings of various digital LEDs.
Espressif IoT Development Framework.
The code was tested using the following:
- ESP32-DevKitC board
- LED strip with 300 WS2812B digital LEDs
- custom level convertor
- good quality 5V power source
Main tools used where Espressif IoT Development Framework and ESP32 toolchain for Linux (see Standard Setup of Toolchain for Linux for the latest version).
Editing was done in Visual Studio Code but for shorter periods of time I have used Eclipse IDE for C/C++ Developers and Atom editor.
Version control with Git.
esp32_digitalLEDs's software and documentation is released under the GNU GPLv3 License. See the LICENSE-GPLv3.txt file.
esp32_digitalLEDs's hardware schematics are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
See the LICENSE-CC-BY-SA-4.0.txt file.
I have tested the MartyMacGyver's ESP32-Digital-RGB-LED-Drivers. The code is working OK, but it captures the whole RMT peripheral because it uses its custom interrupt handler routine.