oritron

Joined 7 years ago

Karma
350
Submissions
38
Member since
Mar 23
OriBarbut dot com
View on Hacker News

Recent submissions

Comment · 5 months ago
I haven't benchmarked Bluetooth on these devices but have you looked at your uncompressed audio rates over WiFi? OP was asking about Bluetooth at high quality and low latency, which I don't think is a possible combo, hence suggesting another ESP32 if wireless is necessary. If it isn't, a wire difficult to beat.

ESP-NOW is another option to look at, which of course won't work to transmit to a phone directly but can do a point-to-point or multicast transmission between ESP32 devices. I've used it in some projects but not for audio, I couldn't tell you how much of a buffer would be needed to make that work smoothly.

Another option for OP, if the audio is being synthesized then the parameters could be transmitted rather than the audio samples themselves and do synthesizing on the receiving device.

Comment · 5 months ago
Low latency in Bluetooth audio comes down to codecs and the best are proprietary.

If you want to really cut down latency and need wireless with hardware like this, you could use a second ESP32 and send your own bitstream between them.

Comment · 5 months ago
Comment · 6 months ago
Nordic Semi, or maybe ST Micro. I've got an STM32WB on my bench at the moment with sensitive coulomb counting and it looks very promising but without all those radios. Of course with all those radios (ie, if you need LoRa on a watch... which is a design decision I'm also skeptical of) then Nordic has a good track record.
Comment · 6 months ago
I like a good smart watch and I appreciate open source, but an ESP32 isn't a great pick when low power consumption is important and the device is going to be communicating regularly. I'm surprised LILYGO went that direction in a watch form factor.
Comment · 7 months ago
My recollection is that a rocket design was scaled up from one that worked, by people who didn't consider how an o-ring should be loaded in order to function properly. They inadvertently changed the design rather than simply scale it. I don't think Feynman got this wrong either. His demo was because the justifications for flight were based on the fact that failure had a temperature correlation, and they had a model representing how damaged the o-rings would be.

The o-ring failure was a measurable consequence of the joint design failure. The data behind the model didn't go down to temperatures as low as that at Challenger's launch date.

For more inappropriate extrapolation to justify a decision: the data for the heat shield tile loss model was based on much less damage than sustained by Columbia (3 orders of magnitude IIRC).

Now they are looking at the same style of fallacy and don't even have a model based on damage sustained in flights.

Another parallel I haven't seen discussed here yet, though I haven't read all comments: I recall Feynman feeling like he was on the investigation panel as a prop, that the intention of the investigation was to clear NASA of any wrongdoing. They used a model, considered risks, etc. Feynman recognized the need for a clear and powerful visual to cut through an information dump and pull it to front page news. The invitation of Camarda to a presentation with a pre-determined conclusion has the same feeling. I don't know what Camarda can do to put it on a (non-HN) front page today.

Comment · 7 months ago
That's an eye catching stat. What is the impact of starlink satellites on the number, ie what if you drop them from both numerator and denominator?
Comment · 7 months ago
I haven't kept up with Artemis development but I've read extensively about Challenger and Columbia. These two parts of the article stood out to me:

> Moon-to-Mars Deputy Administrator Amit Kshatriya said: “it was very small localized areas. Interestingly, it would be much easier for us to analyze if we had larger chunks and it was more defined”. A Lockheed Martin representative on the same call added that "there was a healthy margin remaining of that virgin Avcoat. So it wasn’t like there were large, large chunks.”

Followed by:

> The Avcoat material is not designed to come out in chunks. It is supposed to char and flake off smoothly, maintaining the overall contours of the heat shield.

This is echoes both Shuttle incidents. Challenger: no gasses were supposed to make it past the o-rings no matter what, but when it became clear that gasses were escaping and the o-rings were being damaged, there was a push to suggest that it's an acceptable level.

There was a similar situation with heat shield damage and Columbia.

In both cases some models were used to justify the decision, with wild extrapolations and fundamentally, a design that wasn't expected to fail in that mode /at all/.

I know the points that astronauts make about the importance of manned space exploration, but I agree with this author that it seems to make sense to run this as an unmanned mission, and probably test the new heat shield which will replace the Artemis II design in an unmanned re-entry as well.

Comment · 7 months ago
What software made the bitmap? Seems like a step earlier in the pipeline could help generate a BOM more easily.
Comment · 7 months ago
> I haven't found any killer use case for it yet

You might dig into an operations research textbook, there are a number of problems solved with linear programming techniques which might make sense for your interface... In fact might be more intuitive for people that way and with commercial potential.

Comment · 8 months ago
Comment · 8 months ago
Ah sorry, I quickly edited that out of my comment! I had the video playing while posting, they were talking about a precursor project for embedded Flutter which this in some ways builds on, /that/ is running on the new RAV4.

One of the example uses given in the talk is 3D tutorials, which I could imagine being handy. Not sure I'd want to click on the car parts for it but with the correct affordances I could imagine a potentially useful interface.

Comment · 8 months ago
Comment · 9 months ago
I'm curious about these long running but non commercial podcasts. Can you share a few (or all)?
Comment · 10 months ago

Live from the official Hacker News API

A modern reader for Hacker News · SvelteKit + Skeleton