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.
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Hi,
I was wondering if you could let me know what the dimensions of of the box are?
Thank you!
The outer dimensions are 100x100x35 millimeter.
Thank you, Robert Oostenveld for this great enclosure for OpenBCI. Since Interaxon does not offer their Muse SDK anymore for the Muse Headband, the Muse has become difficult as a device for research.
A successor can be an OpenBCI module in your case, a device which is helpful for instance for mediation research. It would be highly desirable when this case becomes commercially available which is ready to go and sold by a company. We would probably be one of first to buy it, since lack of time for do-it-yourself projects.
Hi Peter, thanks! I am only a “maker” and have no interest nor the time to make many more of these enclosures and sell them. I think that OpenBCI itself – i.e., the company – would be the most appropriate commercial entity to do this. The 3D design is available already under a CC BY-NC-SA 4.0, anyone interested in commercializing it can come and talk to me.
Having said that, I think that there are more interesting developments beyond OpenBCI, like the Mentalab and especially the Unicorn Hybrid Black. I recently bought the Unicorn, and so far I am very happy with it! It is a complete solution that works much better than the OpenBCI Cyton, and for about the same price. I might make a post about it soon…
Thanks, Robert for sharing your experience, very interesting. The community of experts for these devices is very small, so I really appreciate your great contributions!
Hi Robert,
thans for your great reviews on your personal, hobby and professional blog, which are very interesting to us personally. You previously mentioned that the Unicorn works much better than the OpenBCI Cyton. Are there any features which did not work good with the OpenBCI Cyton? And did you have any problems using the OpenBCI Cyton?
Hi Peter,
I have not used the OpenBCI Cyton for a while, but specific problems which I recall and saw others struggle with include the following: The connectivity with the dongle is not so stable, sometimes requiring requiring multiple attempts to connect, resetting the board, replugging the dongle, etc. The Cyton exposes a lot of details of the Ti-ASD1299 chip, which makes it difficult to make the right choice in configuring the board and hence increases the risk of a suboptimal or incorrect configuration. The technical documentation and design of the PCB has some errors (on SRB1/SRB2), which don’t matter if you only care about getting “some signal” but which cause polarity to be flipped. The wifi shield only works sporadically and hence cannot be relied on. The software ecosystem is rather spotty, there are multiple subprojects that are not functional and seem abandoned.
This is not to say that I am complaining about the Cyton: it is not expensive, it is open hardware and source and it is possible with all open information to debug everything. However, I had expected or hoped that by now (after 9 years of its initial release) there would have been a version 2 of the Cyton board with improved usability. For me it felt that I was spending more time trying to debug than doing EEG, hence I moved on to other systems: the Ganglion (with lower SNR, fewer channels but more usable) and the Unicorn (overall cheaper, more complete as a set, and easier to use).
best,
Robert
Hi Robert,
Thank you for your detailed discussion about the OpenBCI Cyton, which was very helpful and interesting for me personally. I miss also an OpenBCI Cyton version 2, and I miss an issue-free WIFI shield. I have reviewed this topic intensively on my personal website. I don t know if OpenBCI and their developers are interested in developing their products further and resolving issues, or if they only want to sell it until it is dead.
g.tec medical seems to understand something about device construction, how to build devices which are worth buying, what they proof with their Unicorn Black, according to your positive review. I also made good experience with the g.tec medical support. I reviewed several papers about sports sensor accuracy validation which used ECG as a reference on my personal website. Very helpful was for me the information from the g.tec medical support, that they do not know of any manufacturer who has solved the problem of ECG movement artifacts. I was very happy about this information from an experienced device builder. I do not know of any discussion in these sports sensor validation papers about this topic, I did not even read those trough completely yet, since it was not worth it for me personally to this date. But the information from the g.tec medical support was very helpful for me to interpret these papers.
regards, Peter
Hi Peter,
This “Wireless EEG: A Survey of Systems and Studies” just appeared in NeuroImage on https://doi.org/10.1016/j.neuroimage.2022.119774 and might be of interest to you. Note that right now it is only a pre-proof version; I hope that the final version with have a better formatting of Table 1.
best regards, Robert
Hi Robert,
thank you very much for the literature information you gave to me which I highly appreciate. I did not read the paper yet, but I am happy to have this information for a further study of the topic. I recently reviewed a lot of information about low-cost physiological sensor devices, which are not published in high quality scientific journals. There is a danger of loosing time by doing this, since the information which can be found just published somewhere in the web is not always at the highest level.
You mentioned above that the Unicorn Black by g.tec medical is overall cheaper than OpenBCI. I don t know if that is true for Python users. The Unicorn Python API Hybrid Black costs 400,00 € extra:
https://www.unicorn-bi.com/de/product/unicorn-python-api-hybrid-black/
But thank you again for the detailed list of issues you had with OpenBCI. I will have a closer look at it in more detail later on myself. But until know, as far as I can see, none of the issues with OpenBCI you mentioned is severe enough for me personally to stop being interested in OpenBCI. But I can confirm part of what you mention myself, for instance others reported of issues with the OpenBCI WIFI shield. But there is also information available how the issues with the OpenBCI WIFI shield can be solved.
best regards, Peter
Hi Peter,
To use the Unicorn EEG system with Python you don’t have to buy the Python interface and you can save yourself the € 400,00.
The Windows software that is bundled with the Unicorn includes an LSL streamer, and the support for LSL in Python is very good.
Furthermore, the Unicorn serial protocol was described in sufficient detail and allowed me to implement a native Python interface that works on any platform (Linux, macOS, Windows) without requiring any g.tec software.
best regards,
Robert