Unable to bind in development mode?


#1

I recently received my Zymkey4i and I followed the documentation for installing it on our RPi3 running Raspbian (stretch). It’s running with a 2.5A power supply.

When the power is applied, the zymkey blinks rapidly (I’ll guess 5 times/sec)…then stops for 2 seconds…then blinks 5 times/sec for a second then switches to blinking 3 times/sec (for 10 blinks)…pauses for about a second…starts back up at 5 times/sec…pauses…3 times/sec (for 10 blinks)…pauses…and finally continuously blinks at 5 times/sec thereafter non-stop.

Is it supposed to blink 3 times/sec all the time after it’s bound to the device? Or is this normal operation?


#2

@zymbittester

The symptoms you describe indicate that your zymkey is NOT binding correctly. When bound it should blink 1 per 3 seconds.
We are seeing other customers experiencing similar binding failures on 3B+ (but not 3B) and we are trying to dig in to the problem to understand the root issue. (We suspect its related to the 3B+/kernel/stretch combo that drive the I2C interface, but don’t yet know for sure).

To help us in the process, please can you provide the following detail:

  • RPi 3B, or 3B+ ?
  • Stretch version ?
  • Anything else connected to the Pi header - in particular GPIO4, I2C ?
  • Is your zymkey mounted directly to the Pi Header ?
  • Do you have a display connected to the HDMI ?
  • Do you have a battery inserted in your Zymkey ?

#3
  • RPi 3B, or 3B+ ?
    3B+

  • Stretch version ?
    Linux raspberrypi 4.14.98-v7+
    Stretch version 9

  • Anything else connected to the Pi header - in particular GPIO4, I2C ?
    Nothing else connected to the GPIO

  • Is your zymkey mounted directly to the Pi Header ?
    Yes, mounted directly to the GPIO

  • Do you have a display connected to the HDMI ?
    No

  • Do you have a battery inserted in your Zymkey ?
    Yes. Lithium Battery 3V, CR1025


#4

Can you please email (support@zymbit.com) us an image of the back and front of the Zymkey and let us know where you purchased it from.

Thanks


#5

Email sent with photos. I purchased it directly from the Zymbit website.

Let me know if you need better photos.


#6

I’ve been experimenting with creating new Raspbian Stretch images and testing different configurations, and one thing that I have found is that if you set force_turbo=1 in the /boot/config.txt file, then binding will not happen at all. Blue light stays off (never blinks).

This was with a Raspbian Stretch Lite image v4.14 from here: https://www.raspberrypi.org/downloads/raspbian/

Without the force_turbo setting, the zymkey binds.

I made this change with my original SD card and it’s binding now instead of blinking 5 times/sec, pausing, 3 times/sec, pausing, then forever 5 times/sec, etc. Or at least it’s working so far…


#7

Another part that kills the bind is setting a static ip in /etc/network/interfaces.

When I attempt to set a static IP I end up losing the bind doing something like this:
iface regular_wifi inet static
address 10.0.1.26
netmask 255.255.255.0
gateway 10.0.1.1


#9

@zymbittester thanks, this information is helpful, and consistent with what we believe is the/a root issue we are seeing on Pi3B+. We believe we have a fix in hand - currently in test. We’ll update you in 24 hours on the results. Thanks again.


#10

I have a similar issue -
3B+
4.14.98-v7+
9.8
nothing else on pins
battery inserted
bought from your web site.
In my case, it works for a while and then just stops. It requires numerous reboots to get it to work again, only to have it stop. The power supply light is steady on.


#11

more information. Two complete power down cycles and the Zymbit is restored. It lasts about 5 minutes before it fails again. Sometimes the light still blinks slowly, and sometimes it stops blinking.


#12

@mauricebizzarri @zymbittester - we believe have identified the root issue, which relates to how I2C is managed under Stretch. The problem is more apparent on RPi 3B+, for a variety of reasons.
Our dev team has a working solution that is being run through production testing and should be available in a new release within 48 hours. Learn more >

Binding & Shutdown Issues - Solution in New Release

Thanks to you both (and others) for notifiying and helping us identify the root issue.


#13

Thank you for the timely reply. I have set up a modest test script that can test out any solution for an extended period of time.

By the way I have your C software working with my GO test routine. I intend to release the sample GO software to the public domain as soon as I am sure it all works. If there is interest in GO in the Zymbit community I would consider the creation of a Go library that calls your C routines. Using the C to Go library is fairly straightforward in any case.


#14

That is great news! Looking forward to the update.