To have manufactured our own physiological multi-sensor device (ironbci, openbci, phyisiological sensors & PCB) by PCBWay?

Last Updated on September 27, 2024 by pg@petergamma.org

Sellers on Aliexpress offered us a 32 channel EEG device based on the ADS1299. It started selling for around 700 USD. After a view positive feedbacks of Peter Gamma from www.petergamma.org the price has been increased to 5 403 USD:

https://www.aliexpress.com/i/3256802367049230.html?gatewayAdapt=deu2glo4itemAdapt

• the board offers only free returns within 90 days, and no warranty.
• The code for it has to be written by ourselves.
• Also if we look at the1 294 posts about EEG devices we wrote on our site, there is no device which really would fit for our needs.
• So can we build an EEG headset from scratch which fit’s our needs?

PiEEG developer Ildar Rakhmatulin has shown an instructional video how to create a brain-computer interface (ironbci DIY) in PCBWAY:

• We suppose this works also with the OpenBCI modules which are open source.
• The Gerber files for it are available and open source.
• The Gerber file for the WIFI shield is not available. Ask in the www.openbci.com forum for it. It has issues but can be repaired.
• The OpenBCI sellers on eBay and Aliexpess developed modifications of OpenBCI modules:
• – a repaired version of the WIFI shield
• – OpenBCI modules which are higher intergrated which should have lesser issues.
• – OpenBCI modules with intergrated ESP32. This could be helpful to attach OpenBCI modules to real-time databases such as InfluxDB or Firebase.
• Where the OpenBCI modules which are sold on eBay and Aliexpress manufactured by PCBway?
• The price for OpenBCI modules on eBay and Aliexpress remained stable over the last years. These modules seem to have issues.
• Also if we order OpenBCI modules on PCBWay in China we suppose that some of them might have issues, since they are not tested.
• We suppose that the high prices of modules from www.openbci.com comes from the fact that they are manufactured in the USA.
• Furthermore we suppose the modules are tested there which increases the costs, and those we import from China are not tested.
• The OpenBCI architecture is complicated and seems to be difficult to manufacture without issues.

On reddit we found some tips on getting the cheapest component prices when using assembly:

PCBWay – Anyone have tips on getting the cheapest component prices when using assembly?
byu/HurrDurrRGB inPrintedCircuitBoard

• But we do not know if there is a monopol for the ADS1299 by Texas Instruments who wants to keep prices for these modules high, and the ADS1299 is not available everywhere.

Here we found another example how to develop you own PCB with a 2,5 hour long instructional video.

In the web we can find the following information:

• You can estimate rough assembly costs even without a detailed quote, using these thumb rules:
• Simple 2-layer PCB — $2 to $5 per component.

• Medium complexity PCB — $5 to $10 per component
• . High-complexity multilayer PCB — $10 to $25 per component.

04.08.2024

• We do not know how much this is for a 32 channel EEG headset.
• But it seems not to be the 50 000 USD the g.tec multi-purpose device costs
• – and also not the 5 000 USD where devices with 32 channels from mBrainTrain start (this is our hypothesis, we never asked for a quote from mBrainTrain)

Here are more detailed information on Medium about this topic:

https://medium.com/@caidengfeng05/pcb-assembly-pricing-in-2023-a-complete-guide-for-electronics-manufacturers-5a2619731a31

Conclusion of the author Caidengfeng of the Medium article

“PCB assembly pricing depends on a variety of factors. While it varies considerably based on complexity, volume, lead time and other requirements, having an understanding of the key cost drivers helps estimate budgets.

Ongoing engagement with assembly partners, right from design stage itself, is crucial as they can provide valuable DFM feedback and component recommendations to optimize manufacturability and cost.

With meticulous upfront planning and design choices, electronics OEMs can secure quality PCB assembly services at a favorable cost point and accelerate time to market.”

And be sure not to use one of the latest Raspberry Pi models to ground your development on, since who knows what will happen when the next Corona crisis happens.

If we look for instance at this instruction:

To build your physiological multi-sensor device based on the ADS1299 chip from Texas Instruments or based on InfluxDB?

• It might look complicated at first sight.
• But we think it is worth having a look at it how to build it.
• Some components are breadboards, but we can make our own PCB from this instructions.
• And it is the basis for your own EEG headset from scratch based on InfluxDB.
• It seems possible for us personally and does not look too difficult to build such a device.
• And starting with one or two sensors and then develop the device further to our 32 channel EEG headset is something that even physiologist like Peter Gamma from www.petergamma.org can imagine to do.
• If we look at the development of Home Assistant, there is much going on
• but we do not know of much developments for multi-physiolgical sensor devices based on InfluxDB in recent years.
• And we think it is worth having a closer look how to develop such a device also at university libraries as this one:

https://infozentrum.ethz.ch/en

• Eventually we find there a printed circuit board we do not have to develop by ourself.
• And if not and we have to develop it by ourselves, this seems not to be too difficult, if we start one sensor after the other.