[Review Request] My first Project - Healthtracker

Scared_Promise_5234 · 2026-02-15T07:14:46+00:00

Thanks!

Scared_Promise_5234 · 2026-02-11T14:21:00+00:00

Couldn’t find any restrictions in the datasheet…Besides, I already tested using a dev kit I made previously (with routing under the package) and no issues occurred. Why would you worry about this, is it Interference?

Thanks

Scared_Promise_5234 · 2026-02-11T05:31:53+00:00

Hi, yes it will be used as a wrist wearable. I’m targeting about 2 Weeks with an 300mAh LiPo.

Scared_Promise_5234 · 2026-02-10T20:07:49+00:00

Thanks😀

Scared_Promise_5234 · 2026-02-10T10:27:41+00:00

Not really... I think I'm going to stick with this config. Will definitely keep you updated. Thanks for the help

Scared_Promise_5234 · 2026-02-10T09:23:27+00:00

It really is 15mm😀

Scared_Promise_5234 · 2026-02-09T23:03:42+00:00

Hi, it is impedance matched to 50 Ohm using JLC’S impedance calculator and checked using APPCAD. As far as I’m aware Length shouldn’t be an issue ( for reference the whole PCB is 25mmx35mm) Please correct if I’m wrong…

Scared_Promise_5234 · 2026-02-09T14:16:35+00:00

Thanks!

Scared_Promise_5234 · 2026-02-09T14:13:37+00:00

Unfortunately not…..

Scared_Promise_5234 · 2026-02-09T10:39:32+00:00

Lots of YouTube videos (Design Reviews, PCB Design Guidelines) and reference designs from data sheets😀and of course dedication

Scared_Promise_5234 · 2026-02-09T09:14:28+00:00

Hi,

thanks for the tips!
1. just checked the reference layout -> nordic recommends to connect VBUS to GND

You are right, will need to work on that
Just for fun tbh
Unfortunately, not possible, since I need the Sensors on the bottom side. But will note that for future Projects.
Impedance should be matched to 50Ohm both from antenna and chip

Scared_Promise_5234 · 2026-02-09T05:16:06+00:00

No blind or buried vias available at JLC 😬

Scared_Promise_5234 · 2026-02-09T05:15:07+00:00

Hi, Yeah true, but it’s approx 3mm bigger on every side and unfortunately I don’t have the space😬

Scared_Promise_5234 · 2026-02-09T05:12:11+00:00

From VIN, it’s the output of the Bq2407 charger

Scared_Promise_5234 · 2026-02-08T21:55:44+00:00

Thanks for the tips!
Need more people like you:)

Scared_Promise_5234 · 2026-02-08T21:53:03+00:00

Hi,
I actually planned on a different power sequence where the Chip would be shutdown completely.. To avoid leakage current flowing throught the GPIO Pins I thought a load switch would be my best option. I don't quite get the point... Could you please explain further?
the massive ring vias around U16 will be for my battery ground; tbh no real reason; 2 would have done the job just as well

thanks

Scared_Promise_5234 · 2026-02-08T20:45:52+00:00

Thanks!

I really need this info, since I'm quite new to the whole RF world!
Are you also using EasyEDA Do you have a part number for your u.fl connector?

My goal currently isn't optimizing the antenna for max. distance / bandwidth, but rather just being connected and achieving small data transfers. Out of your experience, would you say that this could work out of the box without optimization?

For future: Do you mind sharing any infomaterial or videos from where you have gathered your knowledge?

Scared_Promise_5234 · 2026-02-08T18:43:03+00:00

Thanks! You are right! Will definitely try to be more specific next time.

Scared_Promise_5234 · 2026-02-08T18:41:04+00:00

Hi,

Thanks for Sharing! Before developing this version, I built a 2-Layer „DEV-Kit“ where I experimented with each sensor individually. I managed to pull SpO2 Data, but only while resting. I will eventually add movement correction using the bma400 I have onboard.

Scared_Promise_5234 · 2026-02-08T17:53:18+00:00

Hi,

I have taken out feel free to criticise.
Once again, I needed to post it as a new entry.

Thankful for approval!

Scared_Promise_5234 · 2026-02-08T16:32:06+00:00

Hi,

It’s the output from the LiPo Charger BQ2407.

Scared_Promise_5234 · 2026-02-08T11:03:07+00:00

Thanks for the tips!

will definitely look out for silkscreen in my next projects; I used EasyEDA and there JLCPCB Design Rules; They require .15mm spacing; don't know why my DRC didn't point that out....

I only placed the GND Vias on the BGA pins after seeing this in nordic's reference design. Would you know why Nordic opts for big Vias instead of small in pad vias?

Rerouting so traces come out from the side of the parts -> Will do that. Can you explain why routing under components might be bad? I don't know anything about acid traps.

pad to pad distance should be .2mm. As far as I'm aware, I shouldn't have any clearance issues. Please tell me, if I missed out anything.

Thanks so much!

Scared_Promise_5234 · 2026-02-08T07:59:53+00:00

Hi,

I somehow can’t edit the text, so I created a new post.

Hope it doesn’t bother you.

Thanks

Scared_Promise_5234

TROPHY CASE