The old Fitbit and Fuelband which Aaron Parecki gave me a few years ago (thanks Aaron!) don’t hold a charge anymore. The Fitbit battery is near impossible to replace, and with the Fuelband I decided that as there’s no way of loading custom firmware (which would let me get at data without an internet connection and proprietary apps), it wasn’t worth trying to get replacement batteries. So before throwing the devices away, I took them apart.

I didn’t find out much which I hadn’t already seen in teardowns, but these devices have such strange form factors that it was fascinating to see the engineering up close.

The rubber coating comes off very cleanly. Here you can see some of the funny curved traces used on flexible circuit boards:

The LED array, with “Just Do It” written on the top of the PCB (invisible to the end user). On the sections of flex between the more solid boards you can see the unbelievably fine traces:

On the back of the LED matrix section, with a part number. To the right you can see the jaggedy bluetooth antenna trace:

The fitbit isn’t so interesting. Removing the cap with a heatgun reveals a tiny circuit board with a tiny battery and vibrating element.

I also opened up the dock, as I noticed that the USB cable was power only, with no possibility of wired data transfer. The third pogo pin must be for the reset switch, which is mounted in the dock. There’s a little IC in there too, but I was more interested in seeing how the pogo pins were attached to the board. Turns out they’re just soldered straight on:

I’d love to have been able to flash custom firmware to the Fuelband, it’s a lovely bit of hardware, and manufacturing something like that is completely out of the question for a hobbyist. There are so many fun things which could be done with a device equipped with an LED matrix, accelerometers and bluetooth — a wearable MIDI controller, for example.

That possibility would also have made replacing the batteries worth doing, and in doing so saved the device from the landfill. Free software and open hardware isn’t just political, it’s better for the environment.

The Flex’s long battery life, water resistance and sleep tracking allows it to stay on my wrist pretty much constantly, meaning I never forget to put it on. Their web UI is quite nice, and the syncing process is adequate. It’s stupid that the only get at the data on the device is to sync with an iDevice or upload it to their silo and look at (admittedly rather nice) graphs, but that’s a known bug with these devices (which Aaron Parecki has written at length about.)

The Fuelband can be quite painful to put on if the catch pinches skin, its display is nice, and the fact that it doubles up as a watch which automatically syncs timezone with my computer is pretty great. Their web UI is fairly horrible (doesn’t work at all on Firefox due to JS errors), complete with Nike product advertising and confusing comparison charts.

“Nike Fuel” is a singularly useless unit. I’m imagining the reasoning behind it was something like this:

• Our USP is measuring “all kinds of activities” instead of just steps
• Calories would express this just fine, but we can’t trademark something which already exists, or copyright numbers, and database rights (which might not even cover this — ?) only exist in Europe
• Let’s come up with some new unit which is incompatible with our competitors’ products! In order for it to mean anything to anyone, they’ll have to be able to compare their score with other peoples scores, meaning they have to buy Nike products too!

If this is true, I question Nike’s motives — helping people become more active or using vendor lock-in and social manipulation to sell as many devices as possible.

Obviously it’s the second one, but Fitbit exhibit no such problems and seem to be doing okay. Everything is relative.

Both devices are rubbery wrist straps which can make clothing a little bothersome, but presumably that positioning helps them gain more accurate results as opposed to, say, a belt clip.

I’ve been unable to adequately compare the accuracy of either product. The Fuelband seems to think I’ve done far fewer steps than the Flex, but as I can’t get numbers off the Flex quickly it’s difficult to compare the two. One way would be to actually count how many steps I do one day, and see which device is closer.

I’m looking forward to continuing to use both devices, hopefully beginning to follow in Aaron’s footsteps (no pun intended) and pull the data in to my own site.

#qs #fitbit #fuelband