BeagleBoard to ID-12 Revisited. 1 Euro Interface

Our previous interface to ID-12 was pretty cheap. Around 2 Euros for a Logical level converter and some wires, but as the ID-12 RFID reader does not need any programming or command in order to work, we end up just using the RX line from one of the available channels in our converter. That looks like a waste :).

Taking a closer look to the beakout board we were using, those RX lines are just simple resistor dividers. The board schematics shows two 10K resistors for the divider. That will convert 5V to 2.5V which is a bit too high for the 1.8V signals on the BeagleBoard. As suggested in the comments in Sparkfun (http://www.sparkfun.com/products/8745) a 10K, 20K divider should work better, converting 5V into something around 1.5V... which, we had just tried and it seems to work OK.

So this is the result. Three wires to the BeagleBoard (GND, 5V and UART2 Rx), two resistors and the usual stuff for making the RFID ID-12 send data (see http://papermint-designs.com/community/node/218 for the details).

BeagleBoard to RFID Reader Interface Using 2 resistorsBeagleBoard to RFID Reader Interface Using 2 resistors

cheers
The picoFlamingo Team