o1bigtenor:
> On Sat, May 13, 2023 at 9:33 AM jeremy ardley via Dng
> > On 13/5/23 22:21, o1bigtenor via Dng wrote:
...
> > You have multiple serial options including wireless links.
> >
> > - RS-485 ~ 100m
> > - SPI ~ 10m
> > - I2C ~ 3m
> > - 1-wire ~ 30-50m
> > - bluetooth ~ 3-5m
> > - wifi ~ 20-50m
> > - Zigbee 10-100m
>
> I'm sorta quite allergic to wireless - - - - imo its a great idea in
> theory but in practice
> - - - well I can come up with at least 3 reasons why its not a great
> idea - - - - grin!
>
> Looks like I'm going to be using RS-485 with some poe power injection modules.
...

If you have multiple connections on the bus, I suggest CAN-bus.
You can make RS485 work similarily, but vanilla RS485 doesn't cope well
with collisions.

You don't "inject" power on theese slower busses, you just deliver
power with a few extra wires in the cable.

If you have local power at the weighting stations, you could just as
well use that.

Regards,
/Karl Hammar