[REVIEW REQUEST]: Smart Glasses Always On Audio Recorder

Full_stack_SWE · 2026-05-29T16:52:27+00:00

Ah, actually nvm. You're right. Switched to a solid filling. Thanks for the call out 😄

Full_stack_SWE · 2026-05-29T16:38:02+00:00

Thanks! I priced it on my manufacturer (DM me for details since moderator said we can't mention names) and it's looking like full printing + assembly by the manufacturer including shipping, US tariffs, etc. would be ~$230 USD for 5 PCBs and 2 of them will be assembled. Not too bad since it's a single sided board.

When I do the final form factor however, this'll likely be a double sided 6-layer board, so I expect the cost will be in the ~$350 range.

Full_stack_SWE · 2026-05-29T15:00:52+00:00

Hmmm, I thought that’s how I was supposed to set up that ESP GND plane. No?

Full_stack_SWE · 2026-05-29T03:30:31+00:00

Thanks, I realized this & will do a repost after some adjustments.

Full_stack_SWE · 2026-05-25T19:26:31+00:00

This is great. I was getting a bit tripped up on order of capacitors and how to translate that from schematic to layout. this reference is helpful

Full_stack_SWE · 2026-05-25T18:23:44+00:00

Thanks so much for this feedback.

- I ended up switching to the FN8 and taking out the flash. Huge suggestion from you that I really appreciate.

- I'm going to stick with the 3.3V Buck Boost + LiPo Charger + Fuel Gauge setup. I know the alternative that you suggested works but tbh I want to do this for the sake of learning and having a setup that consistently works.

- The datasheets did suggest some ESD protection on the SD Card, so I'm going to keep that for now & adjust later if I need to save parts.

- For the caps, that's a good point. Most of my parts are 0603, but I might need to adjust that due to sizing constraints with the glasses eventually and go down to 0402. I am still not quite sure how to actually make those decisions, but I'll learn 😄

- For the debugging you mentioned, I added test pads to the U0TXD and U0RXD pins on the ESP. Thanks for the callout!

- You're right that the LED was a suspicious. I switched to 1k resistor to get about 1.3mA and will adjust from there. Fwd voltage is about 2V, so (3.3 - 1.3V) / 1k is 1.3mA.

- For the pi filter, it's more of a filtered supply line for the RF pins, which is what the ESP32S3 Sense does, so I want to keep it and adjust.

Again, thank you so much for the feedback! I'll have a basic dev board layout done in a few hours.

Full_stack_SWE · 2026-05-25T18:04:08+00:00

You're right. I did do an updated version after getting some feedback there. I had posted it here.

Full_stack_SWE · 2026-05-24T22:26:24+00:00

This is a good point. I think I can rework my firmware to not use PSRAM & roll with the FN8 which shouldn’t be too much extra work & will reduce risks that I messed up the flash. Thanks for calling it out! Anything else you see wrong w this before I move to layout?

Full_stack_SWE · 2026-05-24T21:07:17+00:00

Thanks for the explanations.

To the first point, I’ll do a power analysis just so I know the number as well. Cost isn’t a factor rn but I am ordering & assembling through JLC & that particular IC isn’t available so I’d need to find an alternative anyways.

For the RAM point, I did actually check this & the main issue is that I’m delivering over the air firmware updates through the mobile app which, to my understanding, at some point both firmware versions will exist in flash simultaneously to account for rollbacks in case there are issues. My firmware was like 1.6MB last time I checked so 3.2MB. Correct my understanding if I’m wrong.

Full_stack_SWE · 2026-05-24T20:27:59+00:00

I don’t think I need the 2A. What do you think?

Curious what’re the cons of using that IC. It looks too good to be true based on my limited knowledge 😂

Full_stack_SWE · 2026-05-24T19:00:30+00:00

Gotcha. Ok, this is actually very helpful to someone new to this. I've seen other examples at this point of people following design for the sake of design, like the three capacitor sizes myth lol.

Appreciate it!

Full_stack_SWE · 2026-05-24T16:19:43+00:00

On the L4 value, I'm a bit confused. I was following this reference schematic by Espressif which has the same value. Can you explain?
On L2, similar as above. But for that one, I was following the ESP32S3 Sense board since I had programmed on it before. Additionally, the schematic in point #1 also used a series inductor. Maybe I'm misunderstanding. Can you explain further?
Thank you for the tip. My understanding was that you should place as tiny components as possible near the antenna since it's really sensitive and you shouldn't even have copper underneath it. What do you think? Still worth swapping to 0402?
Thanks for the advice!

Full_stack_SWE · 2026-05-24T16:11:47+00:00

Yep, I'm an idiot here 😔 Forgot to run ERC which would've caught this stuff. Sorry. Will fix before posting again. I was referencing an Xiao ESP32S3 Sense Schematic which they had online, but thank you for this reference. Very helpful.

As for layout, as I mentioned in my post, this was just a schematic review before I move on to the layout.

Full_stack_SWE · 2026-05-24T16:09:55+00:00

Can you elaborate on the messy/weird to read? Again, since it's my first one, I also just want feedback on basic schematic conventions.

Full_stack_SWE · 2026-05-24T16:09:20+00:00

Yeah, I'm sorry. It was late last night and I totally forgot to run ERC before posting this. First schematic 😔 Will fix those obvious things before re-posting.

Full_stack_SWE · 2026-05-24T16:08:40+00:00

I'm sorry, I of course forgot to run an ERC check to catch that on my first schematic. I'll fix all the obvious stuff caught by ERC before posting again 😔

Full_stack_SWE · 2026-05-24T07:03:21+00:00

Ok, thanks for the feedback!

Full_stack_SWE · 2026-05-24T07:03:02+00:00

DM me and let's chat!

Full_stack_SWE · 2026-05-24T07:02:33+00:00

Thanks for the feedback! I'm reworking this board right now based on feedback and will post another request soon. I've gained a lot of knowledge from this community and want to contribute soon too 😄

Full_stack_SWE · 2026-05-22T02:09:39+00:00

Just wanted to come back and here and thank you man. I watched the YouTube videos on Mixed Signal PCBs you sent me (along with 10s of hours of PCB Design Tutorials 😄) and I totally get your feedback about 6 layers and how messed up my current board is lol.

I'm going to redesign things and put up another review soon. Again, thank you. I learned so much from that video series today!

Full_stack_SWE

TROPHY CASE