On 18/12/2020 14:17, John Rumm wrote:
On 18/12/2020 13:13, Fredxx wrote:
On 18/12/2020 10:25:02, John Rumm wrote:
Quick little electronics hack project for those interested:

http://wiki.diyfaq.org.uk/index.php/..._serial_to_USB

(early draft - so typos may abound!)

I use a Belkin RS232 to USB converter as you can still get drivers for
these.

Yup the RS232 to USB converters work fine (ish - I have had some
chipsets that worked and some that did not in the past), but the Wacom
drivers that do serial tablets don't seem to want to play anymore, and
the USB drivers dont expect to see a serial tablet on USB. So getting
the USB interface is only part of the problem - you also need to make
the tablet appear to the windows driver as a more recent USB model.

I'm surprised this is an issue where you're using Windows 10?

The Windows drivers should provide a COM port and any application should
be oblivious to whether its talking directly to a serial COM port or a
USB device emulating a COM port.

If Windows 10 sees a USB COM port it will naturally use its own
drivers. Prior to Windows 10 COM ports were a nightmare, hence the
FTDI debacle.

https://www.zdnet.com/article/ftdi-a...silent-update/


It might be worth plugging in your old converters into a Windows 10
machine to see if they are recognised before binning them.

Was not planning to bin them... I have other things that can talk RS232.

The MC145406 changes from TTL levels to RS232 levels. You can get very
cheap TTL level RS232 USB converters though they don't always come
with all the signals I believe you might need.

I would suggest a Max232 if you want a simple to use driver, since it
will run off a single sided 5V supply.

Nice project.

Well I had had the bits sat there for a couple of months - just needed
an appropriately shaped tuit! So thought I would give it a try.

ISTR there is another much smaller Wacom floating about - I might have a
go at that next, since I have another Teensy.

Two of the signals sourced from the MC145406 are grounded. Why, does
this cause any issues? I presume these would normally be handshaking
lines used to buffer data.