Safe pins to connect a Bosch ARD-AYK12 - RFID Proximity Reader ?

[GeorgeFlorian]

I am using the following sketch on an ESP32-EVB which is connected to a Bosch ARD-AYK12 - RFID Proximity Reader.

The connection is made directly to GPIO 13 and 14.
As per the ESP32-EVB schematics:
- GPIO 13 has a 2.2k resistor.
- GPIO 14 has a 10R resistor.

This library states:

Device detection
This library supports detection of the card reader.

Use Wiegand.onStateChange() to listen to plug/unplug events.

To use this feature, you'll need to add a pull-down resistor on both data pins. This will set the input on a invalid state (LOW-LOW) when the reader is unplugged.

I have errors reading RFID cards and the function that listens to plug/unplug events gets triggered.
If I comment out that function, I still get errors when reading RFID cards.

Code Select Expand

Card read error: Unsupported message formatUnsupported message format - Raw data: 25bits / 003EE19F
Card read: 24bits / 1F70CF
State changed: DISCONNECTED
State changed: CONNECTED
Card read error: Communication ErrorCommunication Error - Raw data: 23bits / 1B2061
Card read: 24bits / 0D9030
Card read: 24bits / 1F70CF
State changed: DISCONNECTED
State changed: CONNECTED
Card read error: Communication ErrorCommunication Error - Raw data: 23bits / 1B2061
Card read: 24bits / 1F70CF
Card read: 24bits / 1F70CF
Card read error: Unsupported message formatUnsupported message format - Raw data: 25bits / 003EE19F
Card read: 24bits / 1F70CF
Card read error: Unsupported message formatUnsupported message format - Raw data: 25bits / 003EE19F
Card read: 24bits / 1F70CF
Card read error: Unsupported message formatUnsupported message format - Raw data: 25bits / 003EE19F
What kind of pins should I look for ?

[LubOlimex]

Do you use the SD card? If not, then you can use GPIO4 and GPIO14 - they have no pull ups. But if we can trust the description, can't be used for detection out-of-the-box (since it requires pull down on the GPIOs, e.g. them connected to GND via resistor). You can still put pull them down manually via wire and resistor.

If you use the card, maybe try pins with same pull up resistors like GPIO13 and GPIO16 (pins 5 and 6 from the UEXT).

But I am not sure if this issue is related to pins.