New v2.1 PCBs arrived so it was time to build a new board, testing this (not so) new design. This new version is mainly about being able to select widely used part. v2.0 suffered from a rare (or at prohibitive price) SD card holder, this new v2.1 fixes this, as well improving several other little fixes (see improvement list on this post).
Building instructions are very similar to v2.0 so I’m not going to explain all of this in details, but the only the differences. If you basically follow v2.0 instructions there shouldn’t be any issue. Here are Jaluino Bee v2.1 related files:
This is Bee v2.1. Not much differences… Looking closely on this side, you’ll notice mini-USB has been replaced with a micro-USB connector (see this forum post). There was an issue with this connector, but on the design itself, but on the parts I ordered: they have small bumps, theoritically requiring holes on the PCB, which has none… So I had to cut those bumps in order to get this connector soldered. Bee user Trev reported he had micro-USB connectors without such bumps, so that’s really just a matter of selecting the proper part.
Micro-USB connector is a little harder to solder than micro- one, since the pads are smaller. Nothing undoable, pads are well exposed to solder tip, that shouldn’t be a problem.
Beside micro-USB, on the left, is C1 a 1µF capacitor, initially designed as a tantalum cap, and finally using a 0805 form factor. v2.1 fixes this by providing smaller soldering pads (note for the curious ones: Bee usually used 1206 SMD form factor, on which you can use both 0805 and 1206 components. I used this to let user choose, in the end, 0805 resistors and capacitors are much cheaper. Still 1206 pads make them easy to solder).
Finally, last main change is SD card holder. This is still push-push type one, but it now has pins clearly exposed outside the case (pins were under the case on previous one, make it quite hard to solder). This time, it’s both easy to solder, and also to source the component.
Building Jaluino Bee v2.1 is quite straight forward, no surprise. Tests went pretty well too. I use several test files designed to limit the number of extra components to the minimum (well, none), using onboard LED to notify tester whether it’s working or not:
- Blink a LED: jal – hex – video
- Real-Time clock: jal – hex – video
- Serial: jal – hex
- Serial USB: jal – hex
- SD-Card: jal – hex – video
