It is good engineering practise to not apply mechanical stress on the solder joints. A shield over this PCBA could double as stress relief and keep the connector and cable together. It is also very good for EMC with 360 connection instead of pigtail for the cable shield.

You can also do this for stub nodes, but with 2*1.3k instead.

UHDI, more of stacked chips (SoC) with clever package design and pinout. Decrease losses in the interfaces to increase bandwidth and decrease power consumption.

The bottleneck might be the PDM microphone data transfer rather than the microcontroller. Approx 3 MHz clock to split on data and sample rate. Might also have to split the bandwidth in 2 for FB and FF if using only one PDM.

It depends on the board stackup. Closely spaced power and ground, then go for via in pad. Widely spaced planes, or ground plane with routed power, then via-cap-pin. For via pairs, the distance between them matters more than their diameter.

Another thing to consider is also the impedances vs stackup. It might be better, from a manufacturing standpoint, to group similar impedance(s) on the same layer(s). Easier to optimize and to achieve the target impedances with a good yield.

Yes. The E-field between the trace and the reference plane(s) spreads out a bit, so ideally those spreads should not overlap to minimize cross talk. Google 3W-rule Copper pour also matters. Could change trace impedance model between stripline & coplanar if clearance is too small

I think it was @QVHenkel who wrote a good summary of the HW design feedback loop issue. What was the motivation for design changes between revisions? Sourcing, mechanical, EMC, functional, scope change? The quality, or lack of, such data is a problem for AI training.

And what does this exact board, dated 2010, have to say about AI assisted routing? I see the shape, but apart from that I doubt it will add anything to the topic.

Not really. Design rule check could help with some, if configured, but that is typically not the case. The default settings are more focused on manufacturing capabilities, like trace width and insulation distances. First thing to check: the stackup

Thanks! Did not really make sense to calculate eye patterns for a 2 layer board based on the top and bottom views in the other post. Also the dielectric thickness would be "a bit" thick...

There are 2 clues in the picture. The heat sink and the white thermal grease. Both are indicators of possibly higher ambient temperature, which is not good for the expected life time. Lower the temp by 10'C and you get twice the life time. Do it again, and get 2x more...

How many layers in this board?

Yes, I have noticed that and also that the schematics samples looked less optimal. For professional use, just that something is open source is not necessarily a must and could have zero benefit. Things like documented work flows, traceability etc matters more.

It's always this talk about the next release as an excuse. Why should we even look at something if it still is early-alpha-prototype-preview...?

It's not about open source, it is more of a technical nature. Let's make a battery powered headphone that is used by a patient during an MRI scan. What would the prompt(s) be and what is the result? Also how are design updates documented with respect to MDR and FDA?

Let's see. There is a lot of teasing about next release from almost everyone, but still no one seems to deliver anything useful for levels above "hobbyist". As a reference I worked in automotive earlier and now in medical.

I really hate this structure with group zones and a tonne of connect by name-tags. Everything is there, technically, but the overview and signal flow is gone. Logical grouping, look at the order of the capacitors for the Vreg and the GND symbol above Q2.

Any connectors or cable glands that penetrate the housing? Ambient temperature range? Vibrations? Submerged operation, or just water splash? Anything RF inside that rules out metal? Electrical insulation requirements? Chemical compatibility? Potting is messy, avoid if possible

Are there high resolution pictures available somewhere of these circuit boards?