Chris Easton

A couple of weeks ago I had the unfortunate problem of my freezer’s auto-defrost not kicking on an the coils freezing completely. This led to my fridge not cooling down past 60. I had to take apart my freezer for the first time to de-ice the coils to get it working again. Then I got the bright idea of using some of the spare temperature probes I have and a spare Pi to monitor temperature. So I wired up a Pi and created a dashboard for monitoring temperatures in Grafana out of a postgres database.

Wiring was really simple, I just followed this guide to wire multiple probes up: https://www.hackster.io/vinayyn/multiple-ds18b20-temp-sensors-interfacing-with-raspberry-pi-d8a6b0

Code looks like this: https://gitlab.com/-/snippets/2491465

A couple of minutes in grafana and I get some cool graphs like this:

Most areas cancelled their planned festivities this year due to COVID-19. But looks like LA took it into their own hands. Looks cool from a drone, probably less cool from the ground, and annoying for dogs. But still pretty neat!

I recently did two things. 1) Upgrade the firmware on my Ubiquiti Access Point and 2) Replaced my router with PFSense running on an old Xeon-based machine I had. This led to a big problem when trying to get my access point to work, it just wouldn’t connect to the controller. It failed to be adopted by the controller so it couldn’t get its configuration. TLDR: The solution was to remove the device when it was turned off, turn it back on and then adopt the access point from the controller interface

I might have a bit of a unique setup. I only have the Access point and use a Linux server to run the software that manages it instead of the hardware they sell. So that might have caused problems. Overall I’ve been incredibly happy with the alien space-ship looking access point. I’ve never had to reboot it to get it to work and it gets pretty good coverage for being under my couch. Plus I dig the PoE single cable connection for when I eventually get into the attic to mount it to my ceiling. So if you’re looking for something good and relatively cheap, I do recommend it. Its about $80 on Amazon: Click here.

Troubleshooting steps:

1. Unplug and plug back in… No dice.
2. Hold reset button with paper-clip for 30 seconds… No dice.
3. SSH to the device to set-inform-url… No dice.
   This one was interesting though. You can run: ssh ubnt@<ip of device> with the password ubnt to get to a busybox shell. From there you can run: set-inform http://ip-of-controller:8080/inform and see if it connects.

At this point I considered reflashing the firmware, but didn’t want to go through all the steps of setting up a tftp server, etc. to boot the image correctly. As a last-ditch effort I just unplugged the access-point, logged into the web console and deleted/forgot device, and plugged it back in. And sure enough it worked. So instead of trying even step 3 above, it makes sense just to forget the device and set it up after step 2 above.

Just verifying this works. Grabbed a photo from my Sony A6300, tapped to my Pixel 3XL, and uploaded from there.