Python script to check binding remotely

I plan on deploying a number of zymkey encrypted Pis out in the field. I have been successful in the set up procedures but I still need to keep an eye out for the blinking LED everytime I reboot my Pi to ensure that it has bounded okay.

How would I go about writing a python script that does this check remotely so that I know the binding has indeed happened everytime the Pi is rebooted remotely.

Thank you for maintaining such an awesome support page!

Good to hear you are almost ready to deploy more zymkeys in the field.

It should not be necessary to " keep an eye out for the blinking LED everytime I reboot my Pi to ensure that it has bounded okay"

If its not coming up reliably every time, something else is not correctly set up. To confirm the nature of the problem, can you try running 20 boot cycles, and share how many times it fails to bind.


It seems like the Raspbian image recently got an update. Would the zymkey scripts be compatible with these? I ask because I have been trying to set up a zymkey on the new image without any luck in phase 1 or phase 2.
I have tried rebooting 20 times and each time the Pi boots up with the LED blinking fast, however as the Pi is done booting up there is no light on the zymkey at all.

can you please clarify what are the “new” and the “old” raspian images you refer to. Thx

ofcourse the older image (before the update was): 2018-06-27-raspbian-stretch
and the newer one is : 2018-10-09-raspbian-stretch

However, I went ahead and reflashed my Pi with the original image and followed the zymkey installation process again. Phase 1 (binding the Pi to the zymkey) went through without issues but when I try to LUKS encrypt my root file system using “Option 2 - Migrate existing SD card to external LUKS storage device” the set up scripts run as expected and the pi reboots. However on rebooting the LED stops flashing completely. This is the part where I am stuck.

Please let me know if I am being unclear somewhere and I will come back with a clarification


can you conform that you did NOT “lock” (by cutting the tab) the zymkey in between changing Raspian versions. Thx

I did NOT cut the lock