I'm currently experimenting with RFID technologies, and have been using the Sonmicro SM130 (RFID Module - SM130 MIFARE® (13.56 MHz) - SEN-10126 - SparkFun Electronics) as an RFID controller with the Arduino UNO.
Everything's going well, but I've at a point where an alternative firmware on the SM130 would be preferable. (I'm looking to have different logic for anti-collision of tag reads.) One of my references led to the following page (http://www.mcqn.net/mcfilter/archives/computers/upgrading_the_firmware_on_the_sm130_rfid_module.html), which suggests to use a modified Arduino (sans-processor) to act as a FTDI connection between computer and RFID controller.
Basically, the suggestion on the site was:
- Remove the ATMEGA processor from the Arduino
- Hook the RFID controller to RX, TX, 5v, GND.
...and once connected to the computer, it would act as a USB-Serial passthrough and the Sonmicro firmware updater should work without complaint.
The catch is that they are using the Arduino Duemilanove, which comes with a built in FTDI chip. I'm using the UNO with the ATmega8U2, and I suspect it's not going to work. (At work now, cannot try until I get back to workshop later tonight.) I don't understand the differences between the FTDI chip and the ATmega8U2, but I see various references in programming guides about how the UNO requires different steps for programming external chips. (i.e. requiring a bridge between reset and ground for some tasks).
I've been going around the forums, wiki, and various corners of the internet... and I'm getting dizzy with what I find. Can someone help confirm whether the above instructions would work with the UNO, or if not, what alternatives I can attempt?