Whats the bare minimum needed to be able to program bare ch32v203c8t6 chips? - Page 1
Forum section: electronics / general

author: keikai
author_rank: Contributor
timestamp: October 23, 2024, 05:13:27 pm
content: I have a bunch of ch32v203C8t6 ( 48 Pin) and using an adapter board for it. I have connected VDD_2, VDD_VIO_3, VDD_VIO_1 to 3.3v and VSS_1, VSS_2 and VSS_3 to Gnd. Boot0 is connected to Gnd. NRST is connected to reset on WchLinkE, As well as Swclk , Swdio and the 3.3v and Gnd to respect pins.However in arduino ide It does not connect, neither does it connect in the wchutility(the WchLinkE works I have tried it with a bare adapter board with only ch32v003 chip). Am I missing something?I am not using an external oscillator. The chip has a internal osc. I just want to see if the chips i bought works so i can then move on from there. The ch32v003 worked without issue when i only had swdio,3.3v, gnd connected( No external osc). So im not sure what is missing.Note: i know the chips pin 1 doesnt align with pin1 indicator on the adapter board. I was confused on which of the 3 circles on the chip indicated pin one so I chose the circle which kept the WCH logo right side up. I found out much later the smallest circle is what marks pin 1 location but I had already soldered all the chips to their respective boards so I just worked around it. So all my connections as indicated in the pictures are correct.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 23, 2024, 05:18:07 pm
content: MORE INFOS HERE ?https://www.wch-ic.com/products/CH32V203.html?some refers to usb jtag spihttps://github.com/openwch/usb-jtag-spiother infoshttps://github.com/wuxx/nanoCH32V203

author: langwadt
author_rank: Super Contributor
timestamp: October 23, 2024, 05:22:52 pm
content: missing VDDA? it might supply the internal oscillator

author: keikai
author_rank: Contributor
timestamp: October 23, 2024, 06:07:29 pm
content: Thought VBAT was not necessary since i remember the datasheet saying that when VDD is powered then VBAT would be powered internally by VDD. I connected VDDA and VSSA but same result. I will try what corgon said to see if it works.if it doesnt i will have to destroy a stm32F103 board and replace the chip with ch32v203 to see if it works since they are pin compatible lol....

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 23, 2024, 06:13:07 pm
content: It can probably be done with a few push buttons and some switch debouncers based on a NE555 or similar.But I doubt you'd want to go that route.

author: keikai
author_rank: Contributor
timestamp: October 24, 2024, 12:19:02 am
content: Dont have 0.1uf capacitors around... Connected all pins the way corgon did just without the caps but nothing. I mean it should work without the caps whether unstable or not but nothing. LinkE doesnt even find it. Tried with boot0 being gnd then boot0 being 3.3v and boot1 being gndReally Id appreciate it if someone tried it without the caps to see if I got faulty units. Also i tried putting 0.2uf across vdd and vss (thats the lowest cap have now) but same issue.the ch32v20x doc says to connect vbat to vddQuotethis is how i connected it:

author: brucehoult
author_rank: Super Contributor
timestamp: October 24, 2024, 01:04:33 am
content: Quote from: keikai on October 24, 2024, 12:19:02 amBigger, even much much bigger, is fine. It's not a tuned oscillator or something -- it's effectively a tiny battery attached directly to the power pin(s) to smooth the voltage.A little smaller is infinitely better than nothing.

author: keikai
author_rank: Contributor
timestamp: October 25, 2024, 02:29:23 am
content: Thanks for the help. I got it to work. Worked on the first chip but then later when i retried it on that same chip, VSSA and VDDA pins died prolly cuz of a tiny amount of leftover flux behind the pins. Another one of the chips had a flash issue(It would read fine but writing failed). the rest work fine.The ch32v203C8 has two sets of pins. Do you know which ones are for usb host vs usb device?

author: nubinstanley
author_rank: Regular Contributor
timestamp: February 15, 2025, 06:20:37 am
content: Hey, how did you get it working finally ?Can you share the final schematic ?

author: mon2
author_rank: Frequent Contributor
timestamp: February 15, 2025, 02:41:47 pm
content: This guy writes a good blog:https://pallavaggarwal.in/category/ch32v003/

author: nubinstanley
author_rank: Regular Contributor
timestamp: February 16, 2025, 03:45:48 am
content: Could only find posts about CH32V003 (which worked outright for me). I was trying to work with the CH32V203C8T6.... 🙂

author: nubinstanley
author_rank: Regular Contributor
timestamp: February 16, 2025, 02:21:35 pm
content: Hey, got it working! Just followed the schematic in here:https://github.com/wuxx/nanoCH32V203Was mentioned in the first response in this thread (Thank you! 😊). Basically the same thing that the OP was trying out.My issue was long wires! I had just tried out an ESP32 C6 WROOM module and had used JST connecter wires (looong) I had lying around. It worked fine. So, used the same for the C8T6 as well - didn't work. Soldered a second chip to another LQFP48 to DIP breakout board using the same type of wires and, of course, that didn't work either. So, tried shortening the wires, and voila!

author: brucehoult
author_rank: Super Contributor
timestamp: February 16, 2025, 10:52:05 pm
content: How long (and short) are we talking here?

author: nubinstanley
author_rank: Regular Contributor
timestamp: February 18, 2025, 02:03:39 pm
content: Quote from: brucehoult on February 16, 2025, 10:52:05 pm1.jpg --> Actual length of the JST connector wires (connected to the ESP32 C6 WROOM module - works though!)2.jpg --> The C8T6 on a breakout board - JST connecter wires made much shorter.

author: brucehoult
author_rank: Super Contributor
timestamp: February 18, 2025, 02:07:49 pm
content: Those are all what I would call short. I'm surprised it didn't work.

author: nubinstanley
author_rank: Regular Contributor
timestamp: February 18, 2025, 02:10:45 pm
content: Quote from: brucehoult on February 18, 2025, 02:07:49 pmWell, I have one more C8T6 (on a breakout - the first one that did not work). I had made the wires shorter but did not test it. Let me do that. If that now starts working as well, it has to be the wires!

author: gnatho
author_rank: Newbie
timestamp: September 02, 2025, 03:52:59 pm
content: I had been struggling with the same problem. I soldered the chip on a bare QFN48 to DIP board, after many trials I managed to read and flash the chip. Here is my connection:3.3V- PINS: 24, 36, 48and 9(VDDA powers the internal oscillator)GND - PINS: 23, 35, 47and 8SWDIO- PIN 34SWCLK-PIN 37(for those who are used to tinker with CH32V003, it seems this chip needs BOTH lines)Actually, the very bare minimum is VDDA(9), and VSSA(and VDD_VIO_3 (48) and VSS_3 (47)

author: drvtech
author_rank: Regular Contributor
timestamp: September 02, 2025, 04:55:10 pm
content: It may not have been the length of the wires but the fact that you were going via a breadboard. The connections on those things are notoriously unreliable and just replugging in order to shorten the wires may have made the difference.