Bluetooth RFID Tagreader

Update 2013-07-20: I published all files necessary to create such an RFID Tag Reader on github: https://github.com/michaelkroll/BT-RFID-Reader


Some time ago I started a small project to create an RFID Tagreader which is connectable to iOS devices. In order to setup a bidirectional connection to a Bluetooth Accessory you must be participate in Apple’s MFi Program http://developer.apple.com/programs/mfi/. In the case where only the UID of an RFID Tag should be transferred to an iOS device, an accessory could act as a Bluetooth Keyboard (which is the only Bluetooth Device which will be discovered by iOS as well as Bluetooth Headsets). Once connected, a keyboard accessory can sent text to any iOS App.

For the RFID Tagreader I developed a schematic, created the PCB, soldered the PCB using a reflow oven and finally designed an enclosure which has been 3D printed by a service. I like working with EagleUp, which is a very nice tool tool to create 3D models which can be used in SketchUp.

Let’s start with the assembly of the PCB. The following picture shows the bare PCB manufactured by BETA Layout in Germany.

photo 1

Since I own the Reflow kit sold by BETA Layout, I added the new PCB to the stenciling frame which is part of the reflow kit, which is illustrated on the next picture.

photo 2

Now fix the stencil on top of the PCB and take care that the SMD pads are fitting nicely with the stencil.

photo 3

Now add some solder paste to the left border of the stencil (sorry I forgot to take a picture of this step) and use the putty knife which is part of the reflow kit, to apply the solder paste to the PCB. For a detailed description how to do this, see this video on YouTube: http://www.youtube.com/watch?v=Cn9pHKxltPk. The following picture shows the PCB with solder paste already applied.

photo 1

Now use a pair of tweezers to place the SMD parts where they belong to directly into the solder paste. Now I used the reflow oven as described in the youtube video.

photo 2

After 10 minutes, the PCB is soldered and looks very professional. See yourself!

photo 3

No bypasses created by the soldering process. Everything looks fine. I soldered the missing THD parts, and glued the LiPo in place. I flashed the firmware to the uC and downloaded the firmware to the WT12 Bluetooth module as well.

This is how the Bluetooth RFID Tag Reader looks like, with all parts soldered and the light pipe for the power, tag detected and charging LEDs clipped on.

photo 4

Since the bare PCB is not very handy, I created an enclosure using SketchUp which has been 3D printed by Shapeways. But his is another story and will be published soon, as well as a demo on how the reader can be used with the iPhone.

Update 2012-02-13:

As mentioned above, the bare PCB is not very handy and needs to be put into an enclosure. The designed enclosure consists of two parts: A bottom and a top shell. Both shells are designed using Google’s Sketchup which are shown in the following pictures:

Screen Shot 2013-11-16 at 18.15.56 Screen Shot 2013-11-16 at 18.16.15

I ordered the enclosure shells at www.shapeways.com using the “Transparent Detail” material. After approx. 2 weeks the two enclosure parts were delivered.

I tried to design two latches to hold the two parts together, but they were to fragile and broke away after I tried to open the enclosure the first time. As a result, the shells are now glued together, which is no problem because all necessary parts are accessible through holes in the enclosure. The picture below shows the bare PCB and another one inside the enclosure. Beside from the fragile latches the enclosure is fitting 100% around the PCB. The power on switch, the keyboard push button, the tree status LEDs and the micro USB connector are accessible!

photo 3

The Picture below shows the LEDs and the keyboard switch:

photo 1

The next picture shows the micro USB charger connector:

photo 2

And the last picture shows the power on/off switch:

photo 5

Please feel free to contact me conceding availability of the reader. The reader is for sale in small amounts, but due to the fact that the reader is hand made it is not too cheap. Please send me an email concerning the price if you are interested in getting one.

See the Video on Youtube how to pair and tag an RFID Tag with the Reader and an iPhone:

Bluetooth HID RFID Reader Pairing andScanning RFID Tags with an iPhone4

Bluetooth HID RFID-Reader Pairing and Scanning RFID Tags with an iPhone4 from Michael Kroll on Vimeo.