Beacon teardown

At the AAPM 2018 annual meeting, attendees received a BLE (Bluetooth Low Energy) beacon that was used to track attendance at sessions for continuing education and SAM (Self Assessment Module) credits.

Little blue beacon
Little blue beacon
Little blue beacon
Little blue beacon

The website stamped on the beacon redirects to a company called Gimbal where you can purchase the beacons for $5 each or get a whole case of 1650 for the same unit price.  They also provide web based software for managing the beacons.  The manual for the beacon contains some specs, instructions for using the beacon with the Gimbal software, and links to API docs for creating apps to use with the beacon.

The beacon opens pretty easily using a quarter.  Most of the beacon’s innards are taken up by a CR2032 coin cell that powers a tiny little circuit board underneath a plastic cover.

Beacon innards
Beacon innards

A bit of careful prying to release the cover (also held down by a couple dabs of adhesive) reveals the circuit board.  Three contact pads presumably for testing/programming are easily visible.

Beacon innards
Beacon innards
Beacon innards
Beacon innards
Beacon PCB
Beacon PCB

Not much identifying info on the little IC at the heart of the beacon.
4348695
2500D0A
2AJ
P36V G4

Guessing the first number would be a product identifier with the next line (2500D0A) maybe being a date code.  Google led me to a reasonably informative post about the beacons.

Seems to be a fairly simple device and beacons in general might be something fun and interesting to get into.

Breadboard jumper wire reference

Used an Adafruit Perma-Proto board to make this reference guide for the breadboard jumper wires I’ve acquired recently.

Jumper wire reference
Jumper wire reference

The bottom one has wires from sets that I bought before my local Radio Shack stores closed, and the top ones are from the 700 piece kit from Sparkfun. Since they each used different colours for the various lengths, I thought it would be useful to have a reference guide for what length each colour was.

Bench power supply

A Sparkfun bench top power board kit let me take a 300 W power supply salvaged from a dead computer and use it as a bench power supply.

It’s a handy little kit that takes the power supply motherboard connection and breaks out the +12V, -12V, 5V and 3.3V DC to fused 5 way binding posts.

Sparkfun bench power supply kit
Sparkfun bench power supply kit
Computer power supply
Computer power supply

According to the label on the power supply, it can source 17A at +12V, 0.2A at -12V, 19A at 3.3V, and 15A at 5V. That should be more than enough for any projects I’ll run off it.

I also picked up a few of these simple little 3-digit voltmeters that I’ll connect across the outputs to show the voltages.

Next will be to figure  out an enclosure to contain everything.

Resurrected power supply

A couple years ago, the power supply in my computer went belly up because the power switch had corroded and stopped being a switch.

No idea what caused it to become so badly corroded, but I finally got around to finding a new switch for it. The new switch fit perfectly into the opening, and getting it reconnected was a pretty simple job.

Now I’ve got a couple of power supplies to work with. Plenty of projects out on the web describing how to turn computer power supplies into useful bench power supplies, and I could definitely use a couple of those on the workbench.