baobrien

10 ms·

61.
by baobrien 8y ago
I'm really impressed with the bandwidth. Being analog and only having back-scatter for the modulation, I thought it'd be way worse than current digital or old analog schemes, but from the paper, they're saying 2.8Mhz worst ca
62.
by baobrien 8y ago
GPS Satellites are in MEO, so AFAIK, it's possible to get a GPS track in LEO -- assuming the receiver isn't artificially altitude and speed capped.
63.
by baobrien 8y ago
Things don't really leave the gravitational pull of the earth -- it's still on the order of 9m/s^2 in low earth orbit. In order for things to stay up, they've got to be moving around 9 km/s sideways -- essentially c
64.
by baobrien 9y ago
From what I've heard, the consumer end gear supposed to use phased arrays "about the size of a pizza box" and cost in the range of $100-$300.
65.
by baobrien 9y ago
I was able to see the article in private mode on Firefox 59.0.2 with uBlock Origin (enabled and disabled).
66.
by baobrien 9y ago
I love seeing that kind of crazy soldering. I would have had to make an SD-shaped PCB and heat gun the part on. Also (2016)
67.
by baobrien 9y ago
Couldn't you figure out the resonant frequency automatically by hitting the glass with a few impulses from the speaker and looking at the response? That'd be a fun signal processing exercise.
68.
by baobrien 9y ago
It also probably didn't help that Jazelle was locked behind an NDA.
69.
by baobrien 9y ago
With WireGuard you have one public/private key pair for that interface, and a list of public keys for trusted peers. Access management would still be about the same -- each engineer would have a key pair, and you'd have the public
70.
by baobrien 9y ago
This has got to be very slow, both in hardware and software implementations, compared to IEEE packed decimal float. Addition and subtraction on anything other than matched exponents is going to need rounds of multiplication-by-10, however y
71.
by baobrien 9y ago
I don't think hardware support for '754 in decimal mode is very common, but the other points still stand.
72.
by baobrien 9y ago
Like rwmj says, ask somebody at SiFive -- but if I had to guess, I'd say it only breaks out some low speed IO/GPIO lines and a few chiplink lanes. That is to say if you want anything high speed, you're going to have to go thr
73.
by baobrien 9y ago
The SiFive chips (the microcontroller grade FE310 and closer to SoC FU540) both implement the C extension. The FE310 is RV32IMAC and the FU540 is RV64GC. Of course, you can't really hook external ram up to the FE310, and it doesn'
74.
by baobrien 9y ago
Both of the side boosters were re-used for the Falcon Heavy launch. So stock F9s to some extent.
75.
by baobrien 9y ago
With a low bitrate speech codec, you can get well down to 1 or 2 megabytes per hour.
76.
by baobrien 9y ago
From what I understand, the RTL of these cores and a good chunk of the stuff around them is open [1]. The cores themselves are basically all specialized Rocket cores. What you're paying for is probably the ready-to-fab routed cores in
77.
by baobrien 9y ago
I'm not sure about other RISC ISAs, but on RISC-V, register-to-register moves are encoded as "ADDI rd, rs, 0". That is, add 0 (immediate) to rs and store in rd. Canonical NOPs are "ADDI x0, x0, 0", where x0 is the h
78.
by baobrien 9y ago
I think that's called a 'rohtic' pronunciation (never studied linguistic) and carried over into the American dialect from an older English dialect. see https://en.wikipedia.org/wiki/Rhoticity_in_English
79.
by baobrien 9y ago
I think the whole idea with NuScale reactors is that if you take away external power and scram the reactor, there's enough water in the pool to handle the decay heat. After the water boils away, the decay heat is supposed to be small e
80.
by baobrien 9y ago
I agree. Particularly "There are a few ways already that I believe lockups or program crashes can be triggered, but I am looking for the experiences of others."
81.
by baobrien 9y ago
To add, ST has a 'datasheet' and a 'reference manual' for each chip and chip family. The datasheet is usually under 200 pages and is focused more on electrical information and is focused on a few chips. The ST reference
82.
by baobrien 9y ago
I'm not sure about REX, but Esperanto is pretty far away from greenarrays. From what I got out of their talk at the latest Risc-V workshop[3] (video[1], slides[2]), they're going for the big high-performance end of the spectrum. T
83.
by baobrien 9y ago
The Unifi controller is a configuration front end for Unifi devices -- data on the network shouldn't be going through it. It might be a little slower to use, though I've never compared it with the cloud key, but for a home setup,
84.
by baobrien 9y ago
Modern frequency synthesizers can easily do a few Hz step size up in the gigahertz range and be within a few ppm. That doesn't really matter that much though, since modern radios (at least these digital ones) are built as SDRs. They ca
85.
by baobrien 9y ago
It's probably also doing some kind of interleaving along with forward error correction, and would need to collect a few frames before it can start decoding. There's a section on interleaving under convolution coding in the spec, b
86.
by baobrien 9y ago
That's mostly right, the theoretical limit to the amount of information you can carry over a channel is set by the bandwidth and the channel signal to noise ratio. See the Shannon Limit [1]. I should add, however, the lower frequency y
87.
by baobrien 9y ago
If you don't want to pay $80 for the cloud key and don't want to run the controller on one of your machines, the unifi service can also be set up on a raspberry pi pretty easily.
88.
by baobrien 9y ago
Risc-V, 64 bit w/ compressed instructions (strict subset of 32 bit instrs, freely intermix-able) is beating x86_64 right now in static and dynamic code size without vector extensions or anything fancy. With a few simple macro-op fusion
89.
by baobrien 9y ago
You can shoot them a message on the ISA mailing list: https://riscv.org/mailing-lists/ .
90.
by baobrien 9y ago
AMD's open source drivers on recent are pretty solid, AFAIK, and the proprietary ones don't suck.

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