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I got almost all of my wishes granted with RP2350

(dmitry.gr)
700 points elipsitz | 24 comments | 08 Aug 24 13:03 UTC | HN request time: 0.742s | source | bottom
1. TaylorAlexander ◴[08 Aug 24 18:35 UTC] No.41194755[source]▶
This is very exciting! For the last several years I have been developing a brushless motor driver based on the RP2040 [1]. The driver module can handle up to 53 volts at 30A continuous, 50A peak. I broke the driver out to a separate module recently which is helpful for our farm robot and is also important for driver testing as we improve the design. However this rev seems pretty solid, so I might build a single board low cost integrated single motor driver with the RP2350 soon! With the RP2040 the loop rate was 8khz which is totally fine for big farm robot drive motors, but some high performance drivers with floating point do 50khz loop rate.

My board runs SimpleFOC, and people on the forum have been talking about building a flagship design, but they need support for sensorless control as well as floating point, so if I use the new larger pinout variant of the RP2350 with 8 ADC pins, we can measure three current signals and three bridge voltages to make a nice sensorless driver! It will be a few months before I can have a design ready, but follow the git repo or my twitter profile [2] if you would like to stay up to date!

[1] https://github.com/tlalexander/rp2040-motor-controller

[2] https://twitter.com/TLAlexander

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2. sgu999 ◴[08 Aug 24 19:04 UTC] No.41195045[source]▶
> for our farm robot

That peaked my interest, here's the video for those who want to save a few clicks: https://www.youtube.com/watch?v=fFhTPHlPAAk

I absolutely love that they use bike parts for the feet and wheels.

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3. HeyLaughingBoy ◴[08 Aug 24 19:12 UTC] No.41195126[source]▶
I have given some thought to a two-wheeled electric tractor for dealing with mud -- horse paddocks turn into basically a 1-foot deep slurry after heavy rain and it can be easier to deal with something small that sinks through the mud, down to solid ground than something using large floatation tires. Additional problem with large tires is that they tend to throw mud around, making everyone nearby even more dirty.

I haven't actually built anything (been paying attention to Taylor's work, though), but I came to the same conclusion that bike wheels & tires would probably be a good choice. It also doesn't hurt that we have many discarded kids' bikes all over the place.

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4. qdot76367 ◴[08 Aug 24 22:50 UTC] No.41197228[source]▶
Ah, it's good to see you continuing your work with types of robots that start with f.
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5. TaylorAlexander ◴[08 Aug 24 23:11 UTC] No.41197388[source]▶
Hah thats right. I did get some parts to try to update the other one you are referring to, but given all my projects it has not made it near the top of the queue yet.
6. tuatoru ◴[08 Aug 24 23:15 UTC] No.41197401[source]▶
* piqued
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7. GeorgeTirebiter ◴[08 Aug 24 23:18 UTC] No.41197424{3}[source]▶
yes, piqued. English, so weird! ;-)

(Although, interest peaking is possible!)

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8. speed_spread ◴[09 Aug 24 03:22 UTC] No.41198528{4}[source]▶
> English, so weird

Borrowed from just-as-weird French "piquer" - to stab or jab.

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9. teleforce ◴[09 Aug 24 04:27 UTC] No.41198762{5}[source]▶
As other more than 30% of English words [1]:

[1] Is English just badly pronounced French [video]:

https://news.ycombinator.com/item?id=40495393

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10. roshankhan28 ◴[09 Aug 24 05:22 UTC] No.41198988[source]▶
i am not a engineer type of person but to even thing that someone is trying to create a motor is really impressive. When i was a kid , i used t break my toy cars and would get motors from it and felt like i really did something. good ol' days.
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11. throwaway81523 ◴[09 Aug 24 05:35 UTC] No.41199045[source]▶
The motor controller is impressive, but it sounds like a motor controller (as it says), rather than a motor. That is, it's not mechanical, it's electrical, it sends inputs to the motor telling it when to turn the individual magnets on and off. That is a nontrivial challenge since it has to monitor the motor speeds under varying loads and send pulses at exactly the right time, but it's software and electronics, not machinery.
12. bee_rider ◴[09 Aug 24 07:00 UTC] No.41199411{5}[source]▶
It is kind of funny that both of the incorrect versions, peaked or peeked, sort of make more sense just based on the definitions of the individual words. “Peaked my interest” in particular could be interpreted as “reached the top of my interest.”

Way better than stabbing my interest, in a French fashion or otherwise.

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13. littlestymaar ◴[09 Aug 24 07:39 UTC] No.41199609{3}[source]▶
Your description fit what I've seen for rice farming, whose machines usually use bike-like tires.
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14. jhugo ◴[09 Aug 24 07:52 UTC] No.41199661{6}[source]▶
Right, but that meaning isn’t quite right. To pique your interest is to arouse it, leaving open the possibility that you become even more interested, a possibility which peaking of your interest does not leave open.
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15. littlestymaar ◴[09 Aug 24 07:53 UTC] No.41199672{5}[source]▶
> Borrowed from just-as-weird French "piquer" - to stab or jab.

Literally «piquer» means “to sting” or “to prick” more than stab or jab, it's never used to describe inter-human aggression.

And piquer is colloquially used to mean “to steal” (and it's probably the most common way of using it in French after describing mosquito bites)

Edit: and I forgot to mention that we already use it for curiosity, in fact the sentence “it piqued my curiosity” was directly taken from French «ça a piqué ma curiosité».

16. Rinzler89 ◴[09 Aug 24 09:05 UTC] No.41200089[source]▶
>I have been developing a brushless motor driver based on the RP2040

Can I ask why? There's dedicated MCU for BLDC motor control out there that have the dedicated peripherals to get the best and easiest sensored/sensorless BLDC motor control plus the supporting application notes and code samples. The RP2040 is not equipped to be good at this task.

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17. SequoiaHope ◴[09 Aug 24 09:22 UTC] No.41200175[source]▶
> dedicated MCU for BLDC motor control

During the chip shortage, specialized chips like this were very hard to find. Meanwhile the RP2040 was the highest stocked MCU at digikey and most other places that carried it. The farm robot drive motors don't need high speed control loops or anything. We just needed a low cost flexible system we could have fabbed at JLCPCB. The RP2040 also has very nice documentation and in general is just very lovely to work with.

Also SimpleFOC was already ported to the RP2040, so we had example code etc too. Honestly the CPU was the easy part. As we expected, getting a solid mosfet bridge design was the challenging part.

18. vintagedave ◴[09 Aug 24 10:59 UTC] No.41200613{4}[source]▶
I’m curious there. I’ve seen rice paddies plowed in Vietnam and the tractors used wide paddle-like wheels. I saw two varieties: one with what looked like more normal wheels but much wider, and one which was of metal with fins, very much akin to a paddle steamer, though still with some kind of flat surface that must have distributed weight.

Would they be more effective with thin wheels? Both humans and cattle seem to sink in a few inches and stop; I don’t know what’s under the layer of mud and what makes up a rice paddy.

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19. funnybeam ◴[09 Aug 24 11:26 UTC] No.41200771{6}[source]▶
No, French is badly pronounced French - the English (Norman) versions are often closer to the original pronunciation
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20. littlestymaar ◴[09 Aug 24 11:53 UTC] No.41200955{5}[source]▶
What I saw was in Taiwan, but I guess it must depends on the depth of the mud and the nature of what's below.
21. digging ◴[09 Aug 24 15:37 UTC] No.41202882{7}[source]▶
However, in the case where someone means "This interested me so much that I stopped what I was doing and looked up more information," peaked is almost more correct, depending on how one defines "interest" in this context (eg. "capacity for interest"? probably no; "current attention"? probably yes).
22. technofiend ◴[09 Aug 24 16:54 UTC] No.41203507[source]▶
Taylor, wow! I think you're the only person I've actually seen implement WAAS to boost GPS precision. So cool!
23. inanutshellus ◴[09 Aug 24 21:37 UTC] No.41205575{7}[source]▶
All this reminds me of the now-famous quote about English "borrowing" words...

> The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore. We don't just borrow words; on occasion, English has pursued other languages down alleyways to beat them unconscious and rifle their pockets for new vocabulary.

(quote swiped from https://en.wikiquote.org/wiki/James_Nicoll)

24. cstrahan ◴[20 Aug 24 20:54 UTC] No.41303950{6}[source]▶
I think it makes more sense if you consider the expression "this tickles my fancy".

Why do we use "tickle" there? Because a tickle is a type of stimulation, and "fancy" here means "interest", so one is effectively saying "this stimulates my interest".

If we then consult Oxford Language's definition of pique, we find:

> stimulate (interest or curiosity). "you have piqued my curiosity about the man"

The word "piqued" in "this piqued my curiosity" serves as something along the lines of: stimulated, aroused, provoked

This is aligned with the French word "piquer", as a "prick" or "sting" (much like a tickle) would stimulate/arouse/provoke.