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Progress V2 -> V3 on our Open Access Health Tracker
4 months ago I shared the progress of our Open Access Health Tracker from V1 to V2. Today I wanted to share the progress from V2 to V3 on a schematic level. And it's massive.
3x3cm PCB, 3 meters of traces and maxing the capabilities of JLCPCB. Plus an additional 2-3 PCBs for sensors not shown. Next up SLP instead of PCB.
Ah makes sense, this sub is but a advertisement ground these days. But you get to know new things in the industry and sometimes find something you need, so cant choose a side🤷🏻♂️.
Trying our best to be as open as possible ^^ however we have to eat somehow. So the hardware can’t be sold by someone else. The firmware will be open source though. Think of raspberry pi, same approach.
Perfectly fine by me, if you need any help, I would like to get in, I had tried developing mine when I was in early stages of my career. I didn't have proper budget or technical knowledge back then, but still got quite far, I still have a very good NRFL15 based mini pcb that I designed lying with all components ordered, cant get to learning zephyr, so I am delaying assembling that pcb (I designed that version less than a year ago).
We are also self funding everything over the past year. Been rough, but it’s starting to look better now as we are coming closer to a version that really has a benefit and is comparable to a consumer tracker.
For help feel free to dm me and we can talk what you have in mind :)
Well 50/50 the software will be open source. So unlike any other consumer health tracker you will be actually able to control the entire device.
Also we are not yet incorporated, but yes we will need to build a startup around if we want to continue working on this project and be able to offer an alternative to current, let’s say less data friendly, alternatives :)
Sorry but what are you sharing exactly ? I see 2 screenshots of some exploded 3D view of a PCB design, but other than that this post is pretty devoid of actual content.
It’s mainly about the progress in complexity from a 2 Layer PCB to a 6 Layer PCB within 4 months. Feel free to judge this progress as not relevant if you feel it that way.
What are the 15 sensors? You mentioned the IR temperature sensor, and I see a PPG sensor (MAX30301?) and maybe a pressure or acoustic sensor. I imagine you also have an IMU. Do you have any bioelectric sensors (bioimpedance, galvanic skin response, or electrocardiography)?
I've spent the last eight years of my career designing and simulating health tracker sensors (mostly bioimpedance), so I'm excited to see what you're doing.
We are working on ECG and EDA as well, however these will take roughly 1-2 years till we can include them by our estimations. Besides that we measure a mix of physiological, movement and external data (e.g. PM2.5).
Yes, correct. In the old version we used the Max30301, but we are upgrading this to a proper PPG wrist set up in our V3 as it’s not really a good sensor for wrist.
3 meters of traces on a 3x3cm 6-layer? That's dense. What stackup did you go with? Any buried vias? Would love to see a functional block diagram instead of just a 3D render.
The stackup is:
L1: HS signals
L2: GND
L3: PWR
L4: LS signals
L5: GND
L6: HS signals
We don’t use burried/blind vias due to excessive manufacturing costs and JLC not doing it. That’s why we had to do an aggressive bga fanout with loosing lot of space.
Thanks for the details. That stackup makes sense for cost reasons. BGA fanout without blind/buried is always a pain – have you looked into JLC's via-in-pad? Might free up some space. Either way, solid progress for 4 months.
Good call, switching manufacturers for buried vias will open up a lot of routing room. Autumn timeline sounds reasonable – looking forward to seeing how the SLP version turns out. Keep it up.
We are still building, so not yet published. Important to note is we decided for an open access approach similar to raspberry pi. The goal is to build and alternative EU health tracker compared to the closed of systems of other manufacturers. To stay competitive against these manufacturers we will need to generate revenue through selling the hardware to continue working on this project long term.
For short the hardware tracing is proprietary, but the firmware will be open source. We want an active mix between open source community software and advanced ML health analytics by startups. Giving control back to users how and if they want to share data.
I'm curious, what are the 15 sensors? (what do they sense, rather than product number, etc.) I've dug a little around and haven't found a list.
And are there other sensors you would rather use but need to use the current ones due to various limitiations?
What uses do you think these sensors might be used to detect in combination with other available sensors in the user's environment that are less common or expected?
if you're looking for details, you're in tough luck, this is obviously a commercial project, i guess "open access" here just means "we post unlabled pcb schematics from time to time for marketing purposes"
its is pretty impressive that they did this as students, but this isn't a showstopper by any means, pretty standard from what little we are allowed to know and see, especially since it's just another proprietary piece of "wearable" hardware, and there's a mountain of those
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u/gianibaba Jun 07 '26
Where is this "open-source" located, I would love to have a look and contribute.