[mwnn]

I thought I'd be clever and pick up a USB TTL Serial Cable just in case something bad should happen someday...

I've been reading around so I've seen some recommendations posted.

I know I need a cable which operates at 3.3v to ensure I don't fry the router's motherboard. I'd only connect GND, RX & TX to the appropriate pins.


There's at least two variations of the NOKIA CA-42 cable: one made in China, another made in Thailand

I'm not sure if any differences between them could be an issue.

I believe I'd basically cut the top off the phone end and identify the three (five?) wires with a multimeter.

These contain a Prolific PL-2303 chip.

I believe there's driver support on Windows 10 & Linux as long as the chip is genuine.

It's dirt cheap ~£4 which is a bonus!


FTDI are supposedly the de-facto standard.

There's at least two FTDI cables which could be used:

> TTL-232R-3V3 (Connect RX, TX, GND only!)
> TTL-232R-RPI

Price is higher. ~£10 for the latter, ~£15 for the former plus some dupont connectors.

I assume I'm paying for higher quality? Something compliant/tested? Or something more compatible?

FTDI have been bricking & blocking the Chinese imitations that contain knockoff chips and getting some abuse in the process.

Good driver support.


There also the Silicon Labs CP2102 & Chinese(?) CH340 USB boards.

Silicon Labs are supposedly decent.

There's a ton of these USB boards floating around on eBay, etc - but are they up to standard?
https://www.youtube.com/watch?v=RUmQCMezc6k


I think I'd prefer a neater all-in-one USB cable to be honest. Something that's at least tested and been built to a standard.

Any thoughts? It's a bit of a minefield out there.

[Malachi]

Google dd-wrt serial recovery. I have a link in there of the adapters I use.
I have never gotten one of the Nokia clones that worked.

[mwnn]

I'm sure the Silicon Labs CP2102 module on the DDWRT Wiki would've been perfectly fine but for anyone wondering I've ordered this particular USB module:

CH340G USB to UART
http://www.ebay.co.uk/itm/USB-to-TTL-Serial-Converter-Adapter-CH340G-5V-3-3V-For-Arduino-Pi-ESP8266-/322459046657?epid=907542141&hash=item4b140e9301:g:L5gAAOSwdGFY3AT0

It's not an endorsement of this particular eBay seller. I've seen the exact same item and hundreds of other variations elsewhere (i.e. DealExtreme, AliExpress) for slightly less cash.

I just didn't want to wait for a month with untracked Chinese post, customs, no Paypal, no delivery, etc - just to save a pound.


All the clone Arduino boards appear to feature this chip.

The voltages this adapter outputs can be set by jumper. Both the VCC output and the TTL output can be switched between 3.3v & 5v
https://youtu.be/RUmQCMezc6k?t=132

I thought that feature could possibly be useful in some other application.

I believe drivers for this chip have long since been merged into the Linux Kernel. They're also automatically installed in Windows 10. Or available here:
http://www.wch.cn/download/CH341SER_EXE.html

Hopefully I won't end up with a cupboard full of these things...