Communication from reader to registrator RS485 ESP32

Hi,

can somebody help me how to send data from reader to registrator via RS485? There is expander SC16IS752 on both devices so I don't have idea how to start. I'm appending schematics for easier understanding. Devices should be communicating in a way if user scan rfid card on reader it should send card id to registrator, registrator than check for details and send back to reader if succesfull or not...

Tnx in advance.

https://easyupload.io/m/1ym5ss

RS485 is a "physical layer" protocol, like "RS232" or "10baseT"; it doesn't tell you anything about higher level messaging or protocols, making your question similar to "how do I do a PING over rs232?"

I doubt I can help you but please post your schematics in a post, not as a link. It makes it easier for everybody.

Your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advise on) your project :wink: See About the Installation & Troubleshooting category.