USB to RS232 Cable with bare wires

[marrold]

Hi all,

I wondered if anyone had found a suitable USB to RS232 cable with bare wires that did the proper levels for the BBC - I'd like to solder a 5 pin DIN connector straight to the cable and have just the single cable without adapters to use with things like TCPSer and SerialFS

Most of the USB RS232 adapters come with a DB9 moulded on the end with the chip inside so it's impossible to remove and replace with the DIN connector. Searching eBay / Aliexpress just brings up loads of TTL level adapters.

I do know a company that produces custom programming cables for Amateur Radio equipment and it might be possible to twist their arm into producing such a cable. Would there be any interest in a group buy if they'd make some up?

Cheers
Matthew

[IanS]

Most of the USB RS232 adapters come with a DB9 moulded on the end with the chip inside so it's impossible to remove and replace with the DIN connector. Searching eBay / Aliexpress just brings up loads of TTL level adapters.

Why is having an adapter a problem?

Just make a 9-pin d-type to DIN adapter cable, only needs toe be a few inches long. tape/glue/cable tie it all together if you are worried about them becoming sperated.

[marrold]

Why is having an adapter a problem?

An adapter will inevitably get borrowed for something else, and never be seen again.

Tape/glue/cable tie it all together if you are worried about them becoming sperated.

That doesn't sound very aesthetically pleasing

[tricky]

Don't you need to change the levels to get to the Beeb's rs423 (?) Levels of did I miss something?

Actually, I did make a bare word cable in the 90s, but it only worked one way and then only for a few days, but that was when I thought that the beeb has an rs232 port!

[scruss]

Bare-wire USB adapters tend to be TTL level. There are small 4-channel serial level shifters (like these), but I don't think they'd fit inside a DIN plug shell

[marrold]

Don't you need to change the levels to get to the Beeb's rs423 (?) Levels of did I miss something?

Looking at the Data Sheet for the DS88LS120 on the RS423 connector it's rated for +/- 15v so there should be any need to convert between RS232 and RS423. You would need to convert between "TTL UART" and RSXXX however.

[IanJeffray]

USB to RS232 level wire-ended : https://ftdichip.com/products/usb-rs232-we-1800-bt_0-0/
At RS: https://uk.rs-online.com/web/p/interfac ... rs/6877828

[1024MAK]

RS423 uses +5V and -5V levels. As said above, the receiver in the Beeb is compatible with the +12V and -12V levels of RS232.

An RS232 receiver should work okay with +5V and -5V level inputs.

TLDR you can connect a RS232 port to the Beebs RS423 port and it should work.

Mark

[marrold]

Thanks for the suggestions all.

I've managed to track down a cable for a Kenwood TM-D710 Radio that uses Tx / Rx / RTS / CTS / GND at RS232 levels for £19, so it should just be a case of chopping the 8 Pin DIN connector and swapping it for a 5 pin domino.

I will let you know how I get on...

[SteveF]

Tape/glue/cable tie it all together if you are worried about them becoming sperated.

That doesn't sound very aesthetically pleasing

I see your point, but just in case it's a helpful suggestion: could you maybe use large diameter heat shrink tubing as fasten the two together to get a somewhat more tidy appearance? (Edit: Didn't pay enough attention to the last post, but I'll leave this here on the offchance someone else finds this suggestion useful.)