USB to PS/2 converter - CH559 based - Page 1
Forum section: electronics / projects

author: rasteri
author_rank: Contributor
timestamp: September 05, 2022, 06:09:30 pm
content: I've been working on a USB-to-PS/2 converter, so you can connect modern USB input devices to your old PCs.It's based on the WCH CH559 MCU which is a great little part for this purpose, as it has two USB host ports.It supports USB keyboards, mice, and game controllers. So you can plug in a joypad and it'll emulate keyboard presses, handy for games.Source code and PCB/enclosure designs are here -https://github.com/rasteri/HIDman

author: Benta
author_rank: Super Contributor
timestamp: September 05, 2022, 06:36:47 pm
content: Great! They can be bought for less than US$ 5.- anywhere.

author: dl6lr
author_rank: Frequent Contributor
timestamp: September 05, 2022, 07:06:41 pm
content: I'd like the other way round to use modern mice and keyboards with older test equipment. This seems to be non existent...

author: wraper
author_rank: Unknown
timestamp: September 05, 2022, 07:27:48 pm
content: Quote from: dl6lr on September 05, 2022, 07:06:41 pmIt's exactly that, two USB hosts for modern peripherals and two PS/2 outputs.

author: wraper
author_rank: Unknown
timestamp: September 05, 2022, 07:28:40 pm
content: Quote from: Benta on September 05, 2022, 06:36:47 pmYou wish. What is sold are just two connectors with wires in between. Works only with keyboards and mice which already support both USB and PS/2 but only have USB connector.

author: rasteri
author_rank: Contributor
timestamp: September 05, 2022, 08:04:15 pm
content: Quote from: wraper on September 05, 2022, 07:28:40 pmYeah while the first generation of USB keyboards/mice supported PS/2, they're getting increasingly rare.With this you can even use one of those little wireless keyboard/mouse combined dongles

author: tszaboo
author_rank: Super Contributor
timestamp: September 05, 2022, 08:11:01 pm
content: Interesting project, but ..Where do you get PS2 to PS2 cables?

author: rasteri
author_rank: Contributor
timestamp: September 05, 2022, 09:26:56 pm
content: Quote from: tszaboo on September 05, 2022, 08:11:01 pmAnywhere really - I got mine from eBay. They were once quite commonly used with KVM switches.

author: DiTBho
author_rank: Super Contributor
timestamp: September 05, 2022, 10:12:34 pm
content: Quote from: rasteri on September 05, 2022, 06:09:30 pmhi, great project! It can save x11 terminals (PS/2 only)!can you include KiCad files?I'd like to buy a CH559 evaluation board and load your firmware on it, and then use your KiCad project to design a thinner adapter.

author: rasteri
author_rank: Contributor
timestamp: September 06, 2022, 12:02:15 am
content: Quote from: DiTBho on September 05, 2022, 10:12:34 pmKicad files are in the hardware folder.

author: tooki
author_rank: Super Contributor
timestamp: September 06, 2022, 05:59:52 am
content: Quote from: Benta on September 05, 2022, 06:36:47 pmThe $5 ones are passive adapters, as already explained. Active adapters to convert PS/2 peripherals to USB exist as well, but they’re in the $15-30 range. (Though I assume they can be had on aliexpress for pennies.)This is the opposite: converting USB peripherals to PS/2 for use on old systems.

author: DiTBho
author_rank: Super Contributor
timestamp: September 06, 2022, 09:37:29 am
content: _____________________________________________________| ___________________________________________________ ||| |||| |||| |||| |||| ____________ |||| |x___________| |||| | | |||| | hAllo | |||| | | |||| |____________| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| ||||___________________________________________________|||_____________________________________________________|_________________________________________| tektronix |.___________________ | || | | || |==== PS/2 ==== | xterm 400S (*) || |==== PS/2 ==== | ||___________________| |_________________________________________|\\_________USB_______________________________________________________/ //usb /_______________/____________________ //___________________________HHKB JP__\ /usb/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ __/___/____/_/_/_/_/_/_/_/_/_/_/_/_/_/_/___/_/ / //___/__/__/__/____//___/__/_/_/___/__/__/ /_____//_/_/_/touch padYeah, *this* is the evil plan,buahahahahahaah(bad laugh, like Doctor Evil in Austin Poweror something)()

author: dl6lr
author_rank: Frequent Contributor
timestamp: September 06, 2022, 09:57:01 am
content: Quote from: wraper on September 05, 2022, 07:27:48 pmAh, I see. So the PS/2 has to be connected with two 1:1 cable with Mini-DIN at both ends. That wasn't clear to me from your first post (and I didn't viewed the Github yet).Great job then!

author: dl6lr
author_rank: Frequent Contributor
timestamp: September 06, 2022, 10:00:16 am
content: Quote from: DiTBho on September 06, 2022, 09:37:29 amFrom your setup the shift key seems to be somewhat malfunctioning

author: DiTBho
author_rank: Super Contributor
timestamp: September 06, 2022, 01:58:01 pm
content: Quote from: dl6lr on September 06, 2022, 10:00:16 am

author: ebastler
author_rank: Super Contributor
timestamp: September 08, 2022, 11:42:13 am
content: Quote from: tooki on September 06, 2022, 05:59:52 amThese are commercially available as well, but quite uncommon. Apparently people are more likely to preserve and use old keyboards than old computers? They also cost well above $5; Google finds this one in the > $30 price range:https://www.ihse.com/products/usb-ps2-converter/

author: tooki
author_rank: Super Contributor
timestamp: September 08, 2022, 05:38:30 pm
content: Quote from: ebastler on September 08, 2022, 11:42:13 amWell, there really were some awesome keyboards in the past (but mostly before the PS/2 era), but I think a lot of the USB adapters get used for things other than ordinary keyboards. Think (really) expensive ergonomic keyboards, but also things like bar code scanners, "keyboard wedge" card readers, etc.

author: dl6lr
author_rank: Frequent Contributor
timestamp: September 19, 2022, 04:05:16 pm
content: Quote from: rasteri on September 05, 2022, 06:09:30 pmQuestions:1. Is there a fixed assignment of keyb and mouse? How is this handled as PS/2 uses different pins/signals for keyb vs. mouse.2. What about wireless desktops where one USB receiver handles both HID?3. Did you source your chips from LCSC?

author: rasteri
author_rank: Contributor
timestamp: September 25, 2022, 05:53:38 pm
content: Apologies for my delay in replying.Quote from: dl6lr on September 19, 2022, 04:05:16 pmCurrent firmware is fixed, but all data pins of the PS/2 connectors are wired up so it will be flexible. In fact I plan to allow combined Keyboard/Mouse output from one port for dual-use PS/2 inputs (like on some laptops)QuoteThey work great, I recommend their useQuoteI've bought them in various places (ebay, aliexpress). Never come across a broken one.

author: serisman
author_rank: Regular Contributor
timestamp: December 16, 2022, 10:49:24 pm
content: Quote from: DiTBho on September 05, 2022, 10:12:34 pmIn case you're still interested, I designed a thinner adapter for this...https://github.com/serisman/HIDman-mini

author: amyk
author_rank: Super Contributor
timestamp: December 17, 2022, 10:00:48 am
content: I wonder how long it'll be until this product also shows up on Aliexpress... the active adapters that let you use PS/2 keyboard + mouse as a USB one are already <$5.

author: tooki
author_rank: Super Contributor
timestamp: December 17, 2022, 12:54:08 pm
content: Quote from: amyk on December 17, 2022, 10:00:48 amThe market for those is likely larger than the market for this.

author: mikeisfly
author_rank: Newbie
timestamp: September 01, 2024, 03:36:01 pm
content: Can I buy one of these from you? If not I'm not sure how I can buy the components to build this for myself. I would love a guide for a complete noob who has a soldering iron but doesn't want to buy a 3D printer.