HiLetgo 5pcs TTL to RS485 485 to Serial UART Level Reciprocal Hardware Automatic Flow Control UART to RS485 Converter RS485 to TTL

hopefully this saves someone else a little time

Form factor on these makes them a little difficult to use on breadboards. Otherwise works as expected

I do a lot of Home Assistant builds and have used many different types of device. These RS485 controllers have auto flow control and are by far the easiest to get working, especially for novices to this protocol.

I used this between a PZEM-017 and an ESP32 to monitor DC current/voltage. Worked as expected, but note that alot of the online references show TX to RX and RX to TX. I found that this RS485 adapter worked only with TX to TX and RX to RX.outside of that worked perfectly. I only wish it had external led pins for TX/RX led connections.

Did exactly what it should

Don't let the lack of documentation scare you. I bought these to connect a Raspberry Pi Pico to a Zero over a long distance. This was easier than I feared. First enable UART on both devices, then connect Tx of one to Rx of the other and visa-versa. Once you get the communication working just insert these in the path: this time Tx and Rx of both devices to the Tx and Rx of these RS-485 units (Tx to Tx, Rx to Rx). Connect the RS-485 A to A, B to B, ground to ground. That's it, no programming needed, they just work.

They just work, no additional programing.

3 out of 5 did not work. Look somewhere else.