Building your own hitager hardware
The hitager RFID reader consists of two basic parts:
- Arduino master controller (hitaguino)
- RFID board with NXP PCF7991
The follwing two chapters provide descriptions for build your own reader.
Supported Arduino Hardware: Arduino Nano / Arduino Mega2560
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Download the latest Hitaguino release from the Github page
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Flash Arduino (Option 1):
Use Avrdudess (https://github.com/ZakKemble/AVRDUDESS, ~2MB) for uploading the .hex file only (Select "Arduino" as Programmer, Select proper COM Port, Baud Rate "115200", select .hex file in "Flash" section, click Go, wait until programming finished) -
Flash Arduino (Option 2):
Open the .ino file in your arduino IDE, compile & upload it to the board
Hint: It might be necessary to press and release the reset button on the araduino board shortly before upload process starts.
Hitager is designed for using a NXP PCF7991 base station IC. To build your own RFID board, almost every available PCB with PCF7991 (Link to Datasheet) can be used. You can for example get a transponder reader from a car or buy a locksmith transonder tool like Hitag2 v3.1 or ZedBull.
Connection table:
| PCF7991 Pin Name | PCF7991 Pin Nr. | Arduino Nano Pin |
|---|---|---|
| DOUT | 10 | D2 |
| DIN | 9 | D7 |
| CLK | 8 | D6 |
| XTAL1 | 6 | D3 / D9* |
| Mode | 5 | GND |
| VSS | 1 | GND |
| VDD | 3 | VCC / +5V |
* : For Arduino Mega 2560
- Connecting D3 is only required if the ABIC is not supplied with clock source (e.g. Crystal Oscillator) on the PCB. In this case, Arduino's clock output can be used.
- Separately connecting GND is only required if GND is not already connected via USB. In this case connect Arduino GND to PCB GND
- If tool already containing a µC is reused (like ZedBull), it is necessary to "deactivate" it e.g. by tying the mikro's reset pin to GND
Footprint NXP PCF7991 Base Station IC:
Below you find some example hardware which users successfully used with hitager. You can also find some hints about the necessary modifications:
- Connect Arduino according to table
- Do not connect D3, as clock source is already present at the PCB
- In order to stop the µC interfering with the ABIC, it must be held in Reset. This can be done by connecting µC's reset pin to GND
- Connect the tool via USB in order to power it (wiring GND not necessary as it is provided by USB port)
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Adapter can be used without any modification on the PCB
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Connect to arduino according to table below:
Arduino Nano Pin PCF7991 Pin Name IPROG D-SUB PIN D2 DOUT 5 D7 DIN 3 D6 CLK 4 D3 / D9* XTAL1 20 GND GND 36 VCC / +5V VDD 32 * : For Arduino Mega 2560
Schematic of the Iprog PCB:
Hint: Bad HF circuit quality reported here. This may affect the reading quality.
Hint: Move the 0Ohm resistor in the red circle to the empty position right below