Zymbit 4i Cmd processor failure

ZYMKEY4
1

Hi,

Having successfully installed and configured the zymbit with my pi after I rebooted it now fails to work.
The LED blinks rapidly continually.

Checking the service status (systemctl status zkifc.service) gives this error message:
Jul 31 13:22:04 systemd[1]: Starting Zymkey Interface Connector…
Jul 31 13:22:04 systemd[1]: Started Zymkey Interface Connector.
Jul 31 13:22:07 zkifc[1041]: Cmd processor failure

Trying to run example code gives:

python /usr/local/share/zymkey/examples/zk_app_utils_test.py

Testing data lock…
Traceback (most recent call last):
File “/usr/local/share/zymkey/examples/zk_app_utils_test.py”, line 6, in
dst = zymkey.client.lock(src)
File “/usr/local/lib/python2.7/dist-packages/zymkey/module.py”, line 226, in lock
raise AssertionError(‘bad return code %d’ % ret)
AssertionError: bad return code -1

I’m using the Zymbit 4i with a RasPi 4 (4G model) with the official POE HAT and extended gpio pins.
Running stock Raspbian 10.4 Linux 5.4.51-v7l+ #1327 SMP Thu Jul 23 11:04:39 BST 2020 armv7l GNU/Linux
Red power LED is illuminated steadily, no voltage warnings in dmesg.

Any clues as to what might be wrong?
Cheers.

2

Hi Mike,

It sounds like there might be an I2C bus issue. First thing I have to ask is to make sure you enabled the I2C bus via raspi-config or the desktop GUI. Next thing would be a potential conflict of resources with the POE HAT. Can you give me a link to the POE HAT so we can determine what GPIO pins, etc. it uses?

Regards,

Bob

3

Hi,
This is the hat:Buy a PoE HAT – Raspberry Pi

I enabled the I2C bus via the raspi config menu

Edit: I’m also getting a lot of these messages:

[ 423.196749] i2c-bcm2835 fe804000.i2c: i2c transfer timed out

Cheers.

4

@mik_il - We procured one of those POE HATs and we are going to take a look in house.

5

The POE HAT worked for me. I did some experimenting and removed GPIO2-GPIO3, and GPIO4 from the HAT and it still worked. If there was a conflict with the Zymkey, I would expect it would’ve been on those pins.
If you’re seeing a lot of the “i2c: transfer timed out”, double-check the connection of GPIO4 to the Zymkey. Another indicator would be the blue LED. If it flashes rapidly, then 8 slower flashes, it’s having communication problems most likely via GPIO4.

6

Thank you for investigating the issue so thoroughly. I will double check the connections, I suspect it’s the pin diameter of the extended headers I’m using to allow the GPIO pins to be long enough to pass through the hat and to the zymkey - I’d just expected it wouldn’t work at all but perhaps it’s intermittent…