HiLetgo RDM6300 125 KHZ EM4100 RFID Card Read Module UART Serial Output for Arduino

Needed this for a DIY car door lock and ignition using RFID tags. Have an existing 125khz tag programmed into my wedding band, that I use for building access at work and wanted to be able to use the same tag ID for my vehicle. Integrated straight into my Arduino project. I extended the antenna wire leads by about 4 ft so that the antenna is mounted at the top driver side corner of my windshield. The antenna is so thin that it's barely noticeable and it reads my tag from the outside of the windshield from about 4 inches away! Works way better than I expected!

It lit up but wouldn't read any tags. I thought it may be my tags so, I got more. Nope, defective.The antenna wires are DELICATE! If you decide to waste your money on this, tape the antenna and wires to a paper card as soon as you get it. They will break if you're not real careful.

I bought this to interface with my Arduino and a relay to open and close my garage door. This reader will keep transmitting the chip ID the entire time you have the chip in a detectable range. I found it difficult to make logical commands based on this because the data keeps streaming in very quickly every time the program loops. I was able to edit the RDM630 Arduino library to add a rfid.end( ); command that I use to stop the data after receiving a badge ID that I'm granting access with. After my code finishes it's opening the garage door business it enables the RFID to read again with therfid.begin ( ); command// Hope this helps someone who's novice like myself.

I bought this to test the possibility of reading multiple tags at the same time within range of the antenna. The test failed. It may be possible to read multiple tags without special random delay hardware built-in, but this reader can't do it. Otherwise it worked fine the first time I hooked it up. The data coming out is 9600 baud serial. A 0x02 byte proceeds a string of ASCII digits followed by a 0x03 to terminate the string. If you hold the tag in range, it will just repeatedly transmit the ID.This particular antenna has a very narrow range of distance where it will read. It was basically 3cm. The antenna itself is just a simple coil of wire, but the insulated wires attached to it have no strain relief, so handle them with care or they'll break off.

I hooked this up to an Arduino and had no issues coding for it and utilizing it to read and write various tags, and was also able to read Kyber crystals from Disneyland.

Absolute garbage and horribly frustrating. What a waste of time.

Probably I got a dud. I hooked it up to a Mega 2560 (5V/GND), downloaded the library, tried multiple sketches, plugging the Tx in to the various pins required by the sketches and... nothing. I have many 125khz cards and fobs, tested with a reader/cloner and with a working reader. This one didn't see them.As a haiku...Pinout and wires: matchLibrary and power: goodBird did not sing: sad

Works as described. I don't know why others had a problem getting it to work.