QWIIC RFID Not showing up on i2C chain

I have a RPI4 with a QWIIC PiHat. I have several modules attached:

single relay (id 0x18)

2line screen (id 0x72)

4 GPIO module (id 0x27)

and the QWIIC RFID reader kit (KIT-15209) which is supposed to appear as device id 0x7d

Doing a i2cdetect -y 1, I see the other 3 devices (and have written code to test the other 3 devices successfully) but I dont see the 0x7d device.

To make sure it’s not a wiring problem, I daisychained the screen through the RFID reader kit, and have tried using both plugs as input and output respectively, and the screen works, even though I dont see the RFID device on the i2c chain.

I am not very experienced with the i2c physical layer, and keep reading things about pull-up resistors, and wondering if I might have to enable or disable the resistors on one or more of these devices, but I’m grasping at straws here. Currently, all devices are as they were delivered. the PiHat has 4 QWIIC conectors on it, I have tried many combinations of daisychaining all devices from one port vs using one port for each device, and there is no difference.

Is there any thing I need to do to re-flash firmware or something onto this RFID reader breakout? Any other troubleshooting anyone can think of or do I maybe just have a dead device?

Thanks in advance!!

-Steve

Are you able to view it if it’s the only device connected? If not, try also closing the ADR jumper to change the address to 0x7C. If neither of those work, please let me know.

Thanks for the quick response…

Nope… I tried a known good cable, with only the one device on it (and tried again that same cable with the quad GPIO module, which worked) and the RFID module didn’t show up. I figured the controller didn’t need the RFID unit plugged into it in able to respond, so just to make sure it wasn’t interfering, I tried it with and without the RFID module plugged in. I then jumpered the address pads and tried the same tests with the same results.

I’m up for whatever you think is next best troubleshooting…

I see it looks like the firmware is published. If it’s possible to reflash through the .1" header pins, or even the pogo-pin test fixture port if needed, I could try to see if I could reprogram it given some instruction? I’ve got a selection of arduinos of various vintages if you think that’s worth a shot.

Thanks!!

Steve

Before programming, have you tried wiring the INT pin as shown here: https://learn.sparkfun.com/tutorials/sp … e-assembly

I haven’t tried that because those directions are for Arduino, and I’m using a RPi… I also thought the interrupt pin was just for the added functionality to have an interrupt generated when a card is read so you dont have to poll? I could definitely try this, but I’m not clear where I’d connect it to the RPi? I did plug the same module into an Artemis red board and it is also not shown there, so I could do that test on that (or even on an UNO?) but shouldn’t this at least show up on the I2c w/o having the interrupt pin connected?

Is re-flashing it an option in any case?