Reid Carlberg

Connected Devices, & Other Adventures

Safecast: my experience building bGeigie Nano #2333


At ThingMonk last year, I was very intrigued to hear about Safecast and their project mapping radiation levels in Japan and around the world in near real time. So, when this year’s Dreamforce DevZone Internet of Things area was coming together, I made a point to buy a kit for the zone so I could tell a bit about this truly inspirational story to our attendees.

First, I should point out that the bGeigie Nano is relatively easy to build. There are great instructions, and the design of the kit is targeted at amateurs and pretty well tested. If you haven’t done a DIY soldering kit in a while, let me assure you that very few are designed this well.

Step 1 was getting all of the small parts soldered to the main board. These are the resistors, the capacitors, switches, etc. Now I’m far from the world’s greatest solderer, and this board was the first thing I’ve soldered in a few months. However, it still came together just fine.


Next, the system comes with s number of component boards. These add functionality like GPS, data logging and a small screen. The most challenging thing here is holding the headers in place while you solder then to the back of the main board. Times like this, I generally use a little piece of paper, folded up to just the right height, to prop the headers up. Works like a charm!


Now it was time to test the unit, and this is where I ran into my first challenge. I plugged in the USB power cable, and ……….. nothing happened. Using my trusty multimeter, I verified the solder joints and power flow and it seemed like everything was right. I came to the mistaken conclusion that my unit shipped without firmware. So I ordered an FTDI cable to handle that. When the FTDI cable arrived, I plugged everything in and voila! It worked. However, I hadn’t pushed any firmware so I didn’t know why it worked.


The explanation turns out to be relatively simple. The USB connector is designed to charge the battery not operate the board. The system turns on when the battery or the FTDI cable is attached.


The rest of the build went smoothly and today I have a fully functioning radiation logger. Yes, I’ll definitely bring it to Dreamforce.

See you there!


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