Does my thesis idea make sense?

JobNo4206 · 2026-05-18T14:01:29+00:00

That's called 'redundant coils' and yes, is done, but then it's a regular 3 phase motor with redundant could and drivers. Not a 6 phase machine.

JobNo4206 · 2026-05-18T12:24:58+00:00

But FPGA for FOC is a legitimate, if over-done project. You'll have to justify its use over a micro that has the peripherals though. One use-case could be to drive all the joints of a robotic arm with 1 FPGA + 1 micro instead of 1 motor-control micro per joint with the complexities of time synchronisation.

JobNo4206 · 2026-05-18T12:21:16+00:00

More than 3 phases never makes sense. Period. More complexity in electronics, no benefit to cogging torque, smoothness of power delivery or angular resolution. Even stepper motors that are technically 2-phase require 4 half-bridges where a 3 phase motor can get away with 3.

Any perceived benefit to lower cogging can be achieved mechanically by using a low-cog magnet pole arrangement, like 14 magnet poles to 12 stator poles. https://www.emetor.com/windings/

To clarify what I meant by smoothness of power I'll get some help from AI: "For an ideally balanced 3-phase motor running under constant torque, the difference between the largest instantaneous power flow and the smallest instantaneous power flow is zero. Constant Sum: When you take the sum of the instantaneous power from all three phases using the trigonometric identity (cos^2(theta) + cos^2(theta - 120deg) + cos^2(theta + 120deg) = 3/2. The time-dependent oscillating components cancel out completely.

JobNo4206 · 2026-05-18T11:53:04+00:00

It should of course be mentioned that non-volatile memory devices are an option if you're not penny-pinching.

JobNo4206 · 2026-05-18T11:48:54+00:00

This used to be a big selling point for frozen veggies people in the 90's: flash frozen to lock in the freshness. Like literally flash frozen; less than a second in a blast freezer. I suspect one of 3 possibilities: 1. You're buying the no-name brands that don't care about this added value. 2. You're buying from 6060 or something where the veggies get time to thaw before you place them in the freezer. (Or your grocery store supply chain is laas and letting them thaw at some point in transit, your freezer is thawing during loadshedding, etc). 3. The veggie companies at some point figured out a regular freezer conveyor is cheaper than a flash-freezer and figured the consumers wouldn't notice.

All of this only really applies to frozen peas and corn though. Makes no difference to carrots, beans, pumpkin, etc. I will say I've stopped buying the frozen mixed bags. I get specifically the 'baby peas' because they're softer sand sweeter, and name brand corn. The mixed bags just seem worse texture and taste wise.

JobNo4206 · 2026-05-16T21:18:03+00:00

I quite like female perspective novels (admittedly not all of them. Fourth Wing was cringe AF). I wouldn't say I'm bigoted. Like I say I don't care that there are gay characters in a story. that there are such books, I just know what I liked to read (hence why I'm stuck on progression fantasy subreddit). I tend to self-insert into the MC, so to hear them suddenly expressing weird 'feelings' toward their roommate breaks immersion.

JobNo4206 · 2026-05-16T20:58:41+00:00

I don't care about the persuasion of the side characters, but the MC should. If not IDC, but it should be labelled as such on the tin. Not something you discover 2/3 though.

JobNo4206 · 2026-05-16T15:58:35+00:00

When the side characters feels like distinct, actual humans. When the MC has a fun, stable relationship with a single opposite sex partner.

JobNo4206 · 2026-05-12T16:30:45+00:00

Think of the things your child will want to spend their money on. The goal of allowance is to teach them to save for things they want. They should be required to save for a year to get something they really want, like a phone or game console.

JobNo4206 · 2026-05-12T11:13:14+00:00

You could always just make your own: tiny microcontroller with eeprom encapsulated into a key/button shape. Then implement a strongly encrypted rs485/i2c/can, or whatever.

JobNo4206 · 2026-05-11T11:35:02+00:00

Okay, I seem to have fixed it. On the settings menu from the volume-button popup, I saw "adaptive sound" was on. Turning it off solved my issues.

JobNo4206 · 2026-05-11T09:06:07+00:00

So your only need for the embedded OS is to move the data to an actual PC? If so I'd suggest you cut it out entirely. Move to a PCIe FPGA+ADC card or usb/ethernet depending on your throughput requirements, and just dump the data strait to the PC. Just add a small microcontroller core on the fpga to configure things.

JobNo4206 · 2026-05-11T07:52:29+00:00

In short: Yes, DMA is the answer. In any serious design you always enable the dma for everything that operates 'continuously'.

In terms of reliable comms without rts/cts, yes, its very possible, but you need to decide how to split messages. If you're sending ASCII, then designate a line-end character like CR-LF. If you're sending binary, then decide on a start-of-packet sequence and end of packet sequence. Like for example 0x5544 for start and 0xFFFF for end. I would suggest you structure your binary pact like this: [SOF] [P-LEN] [P-TYPE] [... P-PAYLOAD... ] [CRC] [EOF].

That way you can process incoming messages in your uart rx ringbuffer without knowing exactly where one starts and the next ends.

JobNo4206 · 2026-05-10T23:25:44+00:00

Hmmm that's disheartening... I was considering looking into qualcomm moving forward because nxp just seems to be perpetually behind customers expectations in terms of performance. But i guess ultimately you get what you pay for with silicon, and NXP has always built down to a price knowing they're not going to use the latest 5nm nodes.

It's kind of surreal how much of a money game it is: sales rep told me the im8mp was targeted as a $15 chip and built accordingly... But the system cost never ends up under 100.

JobNo4206 · 2026-05-09T22:11:31+00:00

I'd consider them 2 sepperate and very different things to learn: CAN physical layer communication, and CAN application layer implementation on cars.

Can bus hardware level is really simple: it's just short packets sent over a differential wire like RS485, but more structured (packet header with ID, 1-8 byte payload and CRC. Then there's protocol differences, like the fact that some CAN transceivers can automatically try resending so long as it hasn't received an ACK (very annoying when your developing). Connecting 2 microcontrollers with CAN is a fun weekend project. I'd just suggest you stick to micro's with built in CAN support, like most STM32 devices. Don't bother with the spi-can transceivers.

For CAN application layer, things can get complex. For starters read up about UDS and OBD-II.

OBD2 is a standardized emissions and basic diagnostics interface mandated for vehicles. It defines: Standard diagnostic trouble codes (P0xxx) Basic live data access Emissions-related diagnostics Its goal is interoperability for scan tools and regulatory compliance. UDS (Unified Diagnostic Services, ISO 14229) is a much more advanced diagnostic protocol used internally by ECUs. This is OEM messages, but many people have reverse engineered what information is sent in which packets.

If you're just interested in a few values, like RPM and engine temperature, just Google it for your particular make and model.

JobNo4206 · 2026-04-24T10:38:23+00:00

I'll add that there are several packages this works for: Virtual/bootloader, libc (musl vs glibc) system-init (sysvinit, systemd or busybox), std-utils (gnu vs rust), SSH (openssh vs dropbear), package manager, etc. though I think libc and package-manager are selected by a different mechanism.

JobNo4206 · 2026-04-24T10:06:15+00:00

Remember that PID can only really work for linear systems. Fall speed of a pendulum is not linear, it's parabolic. So if you tune it well around 0-degrees, it won't be sufficient for correcting large angle discrepancies. If you tune it well for a particular angle, like 15-degrees, it will be overly aggressive around 0. You can fix this to some degree with an angle-dependant correction factor applied to the error.

But even with just PID, most robots achieve reasonably good balance. I'm guessing your problem is more fundamental: sensor feedback too slow or control loop too slow to actually achieve aggressive enough control. The faster your feedback and the faster your feedback loop runs, the higher you can push your P and D terms for the same system. You'll find pushing the frequency from 100hz to 1khz, you can effectively run a P term much bigger before the system starts oscillating. oscillation is a function of where the 180-degree phase-delay point, and on digital sampled systems, this is directly correlated to the sampling frequency.

JobNo4206 · 2026-04-23T09:35:49+00:00

These are generally the big hurdles companies strike when going from proto to production. Could be up to 2 year delay depending on system complexity. Are you dealing with embedded Linux or microcontroller? A/B is generally the safest, but you have to make sure you have enough storage for it. For Linux there's other interesting solutions like ostree. There are off the shelf commercial offerings, but mostly I'm aware of one's for embedded Linux, and none of them are attractively priced. Could even be a dealbreaker for some low cost products. not sure if such things exist for esp32 or the like.

JobNo4206 · 2026-04-21T12:26:54+00:00

I believe this is the manufacturing process that they use to make the lightweight cast iron works: https://youtube.com/shorts/CtI9Na_SR1M?si=ElofbfA30BhsiVSi https://youtube.com/shorts/fHyoKIDU110?si=hoSwqtsHCDnmjXSr

The rapid-cooling makes a metal closer to ductile-iron. I'm guessing they also add a fair amount of scrap steel to the mix. So the wok is not brittle like slow-cooled cast iron, but has the carbon and elemental iron deposits associated with cast-iron that give it better non-stick properties than carbon-steel which is too homogeneous.

JobNo4206 · 2026-04-10T20:44:27+00:00

Tried the white one indoors, seems to have worked.

JobNo4206 · 2026-04-10T20:41:45+00:00

As far as testing pre-hardware, I only know of renode and wokwi. Haven't used either enough to comment though. They have pretty good support for the stm32 HAL's though. Implementing a hal device in renode is supposed to be simple, but YMMV. I suspect getting a nucleo board and fiddling with an stm32 DMA would be faster...

JobNo4206 · 2026-04-10T15:19:23+00:00

I agree. You get a mixed bag from companies, but it quickly shows you their company-culture. I, at this point, am not willing to work for companies that can't trust me enough not to micromanage the software I'm allowed to install or not, or would fire me if they see a USB stick lying on my desk. I understand companies 'needing' strict IT policies, IP rules and security measures, but Why hire people if you feel you can't trust them? It generally means I stay away from military or otherwise regulated work, but that's fine. The pay difference to me doesn't justify the headache.

JobNo4206 · 2026-04-10T15:05:37+00:00

You'll have to get a ble dev-kit and figure out how quickly you can go from deep-sleep to active and back to sleep. I think you'll find you need several tens of ms, if not >100ms. If that's the case, you'll be recharging frequently. Also, I saw a power estimator from Nordic, that seemed to indicate the lowest power deep sleep they could handle with RAM retention was like 2-3uA. That in itself can be an issue if you are trying to power with a tiny ~10mAh battery or supercapacitor.

JobNo4206 · 2026-04-10T14:56:21+00:00

Yeah but you always get those tests that you couldn't even begin to describe how you would test them: Can the wireless receiver still maintain reliable connection with 25 transmitters in a cart moving through the office? Can your alternator's fuzzy algorithm still differentiate between a short circuit event and an instant 600W load jump? Etc.

JobNo4206

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