# micropython-rp2-rs485-examples

## Whats this?

This is a small collection of some programs I wrote to test the functionality of 
some cheap TTL-UART to RS485 converters, written in [MicroPython](https://micropython.org/)

Here's a short list of the different programs and what they do:

- **rs485_send.py**: sends a incrementing counter (starting at 0) as an UTF-8 encoded string with \r\n as delimiter over rs485

- **rs485_receive.py**: receives utf-8 encoded strings and prints them out as soon as a \n is received.

- **rs485_pingpong.py**: this implements a simple ping-pong over two channels (4 converters needed). For more information, see [Wiring].


## Wiring 

TODO


## Useful links

- [https://www.berrybase.de/2-kanal-rs485-modul-fuer-raspberry-pi-pico-sp3485-transceiver](https://www.berrybase.de/2-kanal-rs485-modul-fuer-raspberry-pi-pico-sp3485-transceiver) - Pinout for a two-channel rs485 converter HAT by waveshare for the pi pico I used during development
- [https://www.analog.com/media/en/technical-documentation/data-sheets/MAX1487-MAX491.pdf](https://www.analog.com/media/en/technical-documentation/data-sheets/MAX1487-MAX491.pdf) - Datasheet of MAX485, a well-known chip soldered on another converter I bought (gives useful insights in how the UART communications work, and how to enable/disable read/write)
- [https://www.python-forum.de/viewtopic.php?t=56795](https://www.python-forum.de/viewtopic.php?t=56795) - German forum entry with sample code
- [https://www.waveshare.com/wiki/Pico-2CH-RS485](https://www.waveshare.com/wiki/Pico-2CH-RS485) - the wiki entry of waveshare about the 2-Channel converter I used among other converters (also contains sample code)
- [https://docs.micropython.org/en/latest/library/machine.UART.html](https://docs.micropython.org/en/latest/library/machine.UART.html) - Documentation of the UART library of MicroPython I used for transferring data to the converters


## License

see LICENSE.md