Jon's Place

Thursday, September 25, 2014

NanoSeeker v2.0 PCB - Time for a redo!

I made a couple mistakes with this new board for NanoSeeker. One mistake was recoverable - I forgot to include a power line on the schematic going to the IMU chip, so I had to solder a wire in place to provide that. Ugly, but it ends up being usable.

NanoSeeker v2.0 PCB, with power wire for IMU

The second mistake was not recoverable. I chose a bluetooth module strictly based on its size, assuming it would work like other bluetooth modules I've used in the past. The module I chose, the BLE113 from BlueGiga, is a bluetooth 4.0 module, and is pretty much useless out of the box. You have to program it in order for it to be useful, which means you have to have some sort of programming interface designed into your board. Okay for a manufacturer who is going to build thousands of boards - not okay for a hobby-level board that is a one-off.

I found a nice, small module made by ST (same company that makes the MCU chip I'm using), that is bluetooth 3.0, and supports SPP out of the box. The module part number is SPBT2632C2A. I got a couple of them from Digikey, and I'm going to ensure that it works before I do anything else.

So, I'm redoing the board, and replacing the old bluetooth module with this new one. I've also made sure to add a power drop to the IMU. I'm going to try a new PCB place (http://dirtypcbs.com/) - they have similar prices but much better shipping options that SeeedStudio, who I used for the last board run.