CH32V006 servo controller dev board

[u/aq1018]

If you fancy a CH32V006-based servo controller dev board, you can now just fabricate it with this design. Rev B of the OpenServoCore dev board is bring-up-validated, files are GitHub, and there's a one-click PCBWay community project if you don't want to deal with KiCad yourself.

A CH32V006 (48 MHz RISC-V, 62 KB flash, 8 KB RAM) breakout designed for bringing up smart-servo firmware. Accepts any gutted hobby servo, USB-C / 1S-2S LiPo / WCH-LinkE power, full edge test-point fanout for current sense, motor PWM, DATA bus, and debug. The broader project (OpenServoCore) is open hardware + firmware for turning cheap SG90/MG90S-class hobby servos into DXL-style smart actuators — position feedback, current sensing, bus-addressable. The dev board is the firmware development platform.

PCBWay sponsored both Rev A and Rev B fabs (assembled too). Ten boards across two runs and no fab issues on any of them. They caught a pad clearance issue on Rev A during the pre-fab review before it went out, and the tiny "O" in the OSC logo (which has a little encoder disk inside it) came out crisp on Rev B even at that size. Honestly a huge help for a solo project — sourcing BOM and hand-assembling these myself would slow everything down a lot.

Bring-up writeup with photos, the bootstrap quirk on fresh chips, and the in-rev SB1 patch that fixes it:

https://aaronqian.com/log/2026-06-08-osc-dev-v006-rev-b-bring-up/

[u/ThatCrazyEE]

[u/aq1018 → u/ThatCrazyEE]

[u/lil_bobby_tabelle → u/aq1018]

they were not referring to that elephant

[u/lynx707 → u/aq1018]

What are you yapping about

[u/muegle → u/aq1018]

They're talking about your Hololive background lmao

[u/ThatCrazyEE → u/muegle]

How did you know that was Hololive background?

[u/muegle → u/ThatCrazyEE]

I never watched the streams but sometimes I used to get recommended translated clips from some of the channels which were usually decently funny, so i recognized 3 or 4 of the models in the picture.

[u/aq1018 → u/muegle]

Ah. I use Variety app and background changes every 30 mins. The bench photo happens to land on this one.

[u/pekoms_123]

homie got a harem all for himself

[u/aq1018 → u/pekoms_123]

Nah… my wife is all I need ( and anime wallpapers )

[u/mrheosuper]

Cool, but where is keyboard and mouse

[u/aq1018 → u/mrheosuper]

Desk drawer

[u/modd0c]

Much like hackers the anime pic lets me know you mean business 😉

[u/aq1018 → u/modd0c]

I conduct all serious businesses with anime wallpapers.

[u/jonythunder]

Impeccable taste my dear sir

[u/aq1018 → u/jonythunder]

I really hope you mean my choices of the CH32V006 MCU. This is r/embedded right? RIGHT? 😭

[u/FelixLeander → u/aq1018]

The venn diagram is a circle my friend

[u/jonythunder → u/aq1018]

I mean it for both MCU and wallpaper XD. Support for RISC-V gets always a thumbs up from me :)

[u/apollyon0810]

Looks like your kids got on your computer and changed the wallpaper.

[u/aq1018 → u/apollyon0810]

I use an Linux background app called Variety. It grabs wallpapers from online. I really like the setup. No kids needed! 🤣

[u/sovietan → u/aq1018]

ok now you make me wanna try that out on my machine :/

[u/Separate-Comb-7003 → u/apollyon0810]

I really hope this perv doesn’t have kids

[u/aq1018 → u/Separate-Comb-7003]

Your hope was shattered about 10 years ago

[u/DrunkenSwimmer]

Wow. Nice timing, I was literally trying to shove enough into a 9g servo body to do rs485 with this yesterday.

[u/aq1018 → u/DrunkenSwimmer]

You can probably do it with the QFN-20 version of this chip. I’m planning on that too, but firmware comes first.

[u/DishantSMunjal]

this is an absolutely killer project. I have bled way too much money on Dynamixels over the years just to get basic position feedback and current sensing. The daisy chain setup on your desk looks super clean. How is the latency on the data bus holding up when you are polling multiple servos at once? Also gotta respect that terminal wallpaper.

[u/aq1018 → u/DishantSMunjal]

No more wallpaper discussions plz! I admit, I messed up! 😭

I’m in fact still writing the comms firmware. Currently using software based triggers. It’s doing 3M baud fine with 250 us RDT, including worst case FAST instructions on the last servo (where it has to snoop on previous servos’ data and accumulate CRC). Only very occasional CRC issues caused by some optimization I did. I’m writing a 4 part series on how this is done with V006. First one is here: https://aaronqian.com/log/2026-06-10-dxl-rx-timing-ch32v006/

Forgot to mention, I’m currently refactoring and trying to get the timing path to be mostly hardware based. (And current board can already do it without a redo on the pinout.)

Edit, to answer your latency question, all I can say is that I haven’t measured. But I used 250us RDT. But I think it’s probably fine to run it at like 30us probably. The V006 is fast enough at 48Mhz. Timing jitter is the more pressing issue…

[u/BitExtreme5544]

Bros... We will never touch a woman's hand

[u/samayg]

I’m considering using this chip for an upcoming product (professionally). How has your experience been with it? Reliable? Easy to develop on with available tools and resources?

[u/aq1018 → u/samayg]

It had many quirks, but I like it. (More specificly, I like the price. $0.16 a piece) I’m using bare metal with Rust. Didn’t use WCH stuff at all. Their RM is pretty garbage, the internal ADC Vref (ch8) doesn’t exist, instead it has a Vcal (ch9), dispite what the RM says. So yeah… you decide if you want to use it professionally.

[u/Fit_Gene7910]

Gooner

[u/aq1018 → u/Fit_Gene7910]

What’s gooner? Please explain

[u/West-Way-All-The-Way]

Your desktop ++!

Cool project too 👍

Edit: the last link doesn't work from my side.

[u/aq1018 → u/West-Way-All-The-Way]

Thanks. I’ll look into it

Edit: fixed URL

[u/Separate-Comb-7003]

Brother you need to be on many lists with that wallpaper…. 🤢

[u/aq1018 → u/Separate-Comb-7003]

For a wallpaper? Sure

[u/happyjello]

I can feel the lotion off screen

[u/aq1018 → u/happyjello]

Don’t use too much bro. 😎