5Pcs MAX485 Transceiver Module, Featuring Chip, Serves as a TTL UART Serial to RS485 Instrument Interface Module. RS-485 Communication Transceiver Operates at 5V Designed for SCM Development Boards

I had a WS2811 12V led strip that was connected to the controller about 30 ft away using sprinkler wire to transmit data. The length was too long and the signals were getting corrupted, so these modules came really handy. One was wired into the control box as the transmitter, the other into the box containing the led strip and set up as a receiver. Look for Arduino Nano TTL to RS485 and wire accordingly. No issues with signal degradation after installing a pair of these.

These work fine. I wish they were a bit more compact. As is they’re impossible to use on a breadboard for prototyping due to length. But they do work and are reliable. And the included terminal block connectors make connection easy.

Did exactly what I needed it to, connect two Arduino boards over long serial lines to do half duplex communication. Tie the DE/RE pins together, and attach to a digitial out on the arduino. Tie the TX/RX to the arduino uart. Drive a high/low after a delay allowing bootloader to function as normal, and provide the ability to select TX/RX from within your program. Layout of VCC/GND pins could be a bit more convenient if they were not on the same header as the A/B bus.

This helped me control my DMX devices with an ESP-32!

This will not work on the RPi. The RPi UART (and GPIO's) are not 5V tolerant. This board runs at 5V. It is really for an Arduino. This should not be sold as a Raspberry Pi compatible device.

There are several better RS485 to TTL boards out there. Keep looking.

I bought these to communicate with a pair of PZEM-016 modules, and then one of my PZEMs died so I returned them both and now I'm down to repurposing these for high-reliability long-range inter-Arduino communication. Which they'll do, of course, because RS485 is funny that way. I have no particular complaints about these adapters. Oh, they could be much smaller, but they probably don't really need to be. They'd be nicer (better) if they were optically isolated, but that would also make them more expensive.

Not much else to say. They're cheap, and they work quite well. I'd buy again.

It's using max485 chip as expected. Received today and tested two of the 5, one as a transmitter and one as receiver. Works perfectly for me. VCC is using 5V, I am inputting 1.5MHz and scope and capture at the other side. All works as expected. MAX485 chip datasheet is saying it supports up to 2.5Mbps. I'm happy!!!

None worked. Purchased similar (identical) units from another vendor, 4 out of 5 of theirs work. Guess who I'll buy more from?