Usb to rj45 cable

hi ll.

need to make a usb to rj45 to flash my pylontec’s with.

i got a old unused mouse… was thinking of cutting the mouse off and using the cable to patch into a RF45.

does anyone know on the mouse/usb side which pins are which.
Just realised, the older US2000’s uses a RJ11.
I’ve got the wiring for the RJ** side, but to which points on the USB do they go?


Don’t you mean rj45?

@georgelza You need a USB to serial converter:

ye ye… typo.

no… don’t have a serial port.
My comm ports sit on USB-C which I can convert to a USB port.

I need the connections for RJ45 → USB
And I’m not paying R400+ for something I’m unlikely to use again in the next 12 months. and as it ends in serial I will need to then convert that to USB still.

Never mind, eina… going to get even more interesting, the US2000’s uses RJ11
and the new US3000C a RJ45

You would need 2 cables… I use one Waveshare converter for everything… USB to TTL, Rs232 and Rs485…

Get yourself a cheap converter from micro robotics and do the cabling yourself.

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Agree with Jaco… BUT you actually only need the 1 for the 2000’s - the new 3000 will be be up to date enough for the Venus. It sees it already :wink:

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Found this.

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This is the one I use, but to me it was worth the money, I use it often.


Wait, I might have an old one in the office, whatsapp me tomorrow morning and ill check for you. Its one of the first ones Manie and his ICC crew sold with their systems… You can have it, as I dont need it anymore. Please allow me to check that its still okay before I commit.


Jaco, I have a ttl-rs232 converter i always use to program the sonoffs with, when I tasmotize them, would that work,it has a vcc/gnd/rx & tx port.

thinking i can from there fit a rj45, i ca then use a female to female adapter and have a rj11/rj45 cable where the rj45 then goes into the female to female, that way i can also plug into rj11.


agree, for you doing this with he guys allot that makes total sense, for me it might be once a yearn a fw update or when i buy additional batteries.
will ping you tomorrow.

i see 2 connect points. thinking i’ve seen everyone refer to min 3 wires,
knowing til/rs232 it is 4, me missing something ?

think would make sense for them to all 3 the same fw ? so would like at doing it in such a way that i can flash them all.

See this thread…

and this

curious, has anyone looked into access the pylontec’s via rs485…
thinking allot of the same coding can be used thats used on the sun sync rs485 port ? and the addresses, simply to pull information.

so just curious, some posting across the inter webs refer to a TTL->RS242 converter required…
some just show a point a wire to point b.
aka do you have to go USB → RS232/TTL converter → RJ??

or can you USB → RJ??

or is it straight connect when connecting to serial port and a TTL/RS232 required when plugging into USB port, just trying to understand.


Sweet :slight_smile: thanks.

No I don’t believe you can. USB uses a differential pair of cables to transmit/receive but it uses USB protocol and only connects to USB devices.
Once we lost the serial port on PCs I noticed LAN to serial converters becoming available but I have no experience with them.

I have one of those LAN/Serial, normally get them with enterprise level network equipment, RS232 one side, RJ11 or RJ45 other side.
Had a Cisco console cable… wish i knew where it was as I think thats like 80% what i need…

I assume the RS232/RG11 wiring as per previous works as it’s a console port and just the connector thats changed so just have to wire point A to point 1 and point B to point X etc…
but now that we moving from a console/serial port on laptop to USB we have protocol changes, thus the introduction of the TTL/USB converter/board…
I’m going to take a guess and like on Sonoff, the TX on the TTL board connects to the RX on the Battery and RX on TTL board to TX on Batter, and then you use the Gnd on TTL Board and then goes onto Gnd on battery (RJ11 or RJ45), there is no VCC on a RJ11