While assembling the touch-proof enclosure for the OpenBCI Cython/Ganglion biosensing amplifier boards, I realized that with the board in the middle of the enclosure, there is little space for the Dupont wires connecting the pins of the OpenBCI to the touch-proof connectors. Trying to squeeze the board in place, some of the solder joints broke off. After repeatedly re-soldering the wires to the connectors, I was able to get it all properly in place. However,  this was definitely a design flaw.

I designed a new version that has the OpenBCI PCB board rotated by 45 degrees and shifted a bit to the corner. This gives more space for the wires and reduces the stress on the joints. Here you can see the new enclosure printed for a 4-channel Ganglion board.

OpenBCI touch-proof enclosure version 3 – with the PCB board in the corner

Compared to the previous one for the Cython, the difference is also in the colour of the connectors: I used 4 pairs of red and blue connectors for each bipolar channel, one black connector for ground, and one blue connector as the common reference. Using the 4 channels (i.e. the red connectors) relative to the common reference requires toggling the micro-switches on the Ganglion PCB board. Using a common reference is handier for EEG measurements, whereas the bipolar configuration is convenient for ECG/EMG, but with some extra electrodes also works fine for EEG. The Cython version has 8 red connectors, one blue connector for the reference, and one black connector for ground.

Another change is aesthetic; thanks to the nice post and configuration files from Rainer I figured out how to 3D print with multiple colours. I updated the Fusion 360 design of the enclosure to include the EEGsynth logo. The logo is embedded in blue and white in the black background of the box.

logo embedded in the 3D-printed enclosure

The 3D design can be downloaded from Thingiverse.