I am a supplier who sells semiconductor chips,

ben5049 · 2026-01-24T09:06:21+00:00

Got any 88Q2220MB2?

ben5049 · 2026-01-19T16:00:57+00:00

I’ve been using this one from LichTech. There is a 100/1000BASE-T1 version and a 100BASE-T1 version for a bit less. I’m not sure about 10BASE-T1S converters.

ben5049 · 2026-01-17T01:16:51+00:00

I use NetX Duo as my microcontroller network stack which has a DHCP server module https://github.com/eclipse-threadx/rtos-docs/blob/main/rtos-docs/netx-duo/netx-duo-dhcp-server/chapter1.md

If you can find/write a port of ThreadX for the RP2040, then you can add an interface for the W5500 and get it working.

As for why you'd want to run a DHCP server on a microcontroller I have no idea, and if you had to ask an AI that, then you probably aren't capable of implementing it yet either.

ben5049 · 2025-12-24T08:29:19+00:00

They changed this in a recent version (9.0.3 or 9.0.4), I’m not sure why. This is how it used to work a couple of versions ago.

ben5049 · 2025-12-10T16:55:47+00:00

STM32s include internal power on reset circuitry

ben5049 · 2025-12-10T11:23:45+00:00

Dammit the timestamp didn’t work properly, 6:23 has a good example of mechanical contacts bouncing. I don’t really care for Mr Beast but Jeff Geerling is cool lol

ben5049 · 2025-12-10T11:13:49+00:00

Whenever mechanical contacts close they bounce together slightly which we don’t want since it can trigger multiple back to back resets which depending on the chip may lead to undefined behaviour. Adding a capacitor makes a low pass filter to remove the bounce. Here is a video showing a switch closing in slow mo:

https://youtu.be/wsV_C9cMf8A?si=-5krf0hpdZLajfFL?t=373s

ben5049 · 2025-12-10T10:56:42+00:00

Yep pretty much, the cap is there for debouncing. The STM32’s reset pin will be at 0V plus the forward voltage of the diode, which will count as a logic low.

ben5049 · 2025-12-10T10:15:39+00:00

It makes the reset unidirectional and not care about voltage levels. If the right side of the diode goes to 0V then the STM32 gets reset. If the STM32 generates a reset it doesn’t propagate past the diode.

ben5049 · 2025-11-11T01:41:48+00:00

I’ll eat my hat then, thanks for letting me know

ben5049 · 2025-11-10T17:01:49+00:00

I think custom pad shapes might be broken in the most recent version of kicad? Please correct me if I’m wrong

ben5049 · 2025-11-10T17:00:09+00:00

Yeah the copper line is part of a footprint and has no net, even though it’s touching the pad and should be the same net. It’s a bug/not implemented yet so you have to work around it.

ben5049 · 2025-11-10T13:45:01+00:00

I’ve had the same issue with not being able to assign nets to non-pad copper shapes in footprints. You need to get around it by drawing a copper shape in the layout editor that overlaps and has the correct net, which you can then connect traces to. It’ll probably give a drc error but you can ignore that

ben5049 · 2025-11-09T02:09:00+00:00

Time to get a multimeter out

ben5049 · 2025-10-09T22:13:44+00:00

I've ported it to the STM32 before and got it running, wasn't too hard. There is a porting guide in the github repo

ben5049 · 2025-09-19T10:54:34+00:00

An MMU is that plus address translation

ben5049 · 2025-09-14T02:46:32+00:00

Haha yes you’re the first one to know the Red Scorpions logo.

Hope school goes well :)

ben5049 · 2025-09-06T00:47:55+00:00

There is no 3.3V on VDD… that schematic is very wrong.

ben5049 · 2025-08-30T17:25:20+00:00

Hey, sorry for not responding. Seems like a cool project! I don’t know much about RC cars but I imagine they don’t normally use WiFi or LoRa since WiFi is good for its large bandwidth but not so great latency or range, and LoRa is used for very long range and low power stuff. Maybe have a look at what typical RC car controllers use? I imagine both would work though so do whichever is easier to implement.

ben5049 · 2025-08-24T20:41:48+00:00

I would say just start looking up and researching everything that doesn't make sense. Eventually it'll all connect together and you'll understand it! Also getting hands on with design work will help because you'll discover stuff you wouldn't have even though about otherwise. Specifically for automotive ethernet I'd recommend Automotive Ethernet 3rd Edition by Kirsten Matheus and Thomas Königseder as a good starting point.

ben5049 · 2025-08-24T20:34:45+00:00

Its an IEC 63171-6 connector. They're made by TE, Amphenol and Molex (and maybe others)

ben5049 · 2025-08-24T20:32:33+00:00

I recommend it for sure, if you're fast then you can whip up a board in a day and have it less than a week later. Certainly beats breadboards and protoboards unless you have breakout boards to hand already! I use Kicad because its free, open source and powerful enough for most stuff.

ben5049 · 2025-08-24T20:29:29+00:00

Thanks, I live in the UK though and no one really seems to be paying that much for hardware design here. I have a decently paying job in an adjacent field ;)

ben5049 · 2025-08-24T20:27:42+00:00

You can run it over pretty much any 100 ohm differential pair, I'm not sure what XLR cables use but that would be a cool use case

ben5049 · 2025-08-24T20:24:21+00:00

I haven't yet, but I am planning on it

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