Mendel USB and power connector
This page describes how to get power and USB into your Mendel from your computer.
Mendel needs as 12 volt power supply capable of supplying at least 5 amps. You can either buy a power brick with that specification, which will be expensive but neat, or you can hack an old PC power supply, which will be cheap but slightly scruffy. You can also run Mendel off a 12 volt car battery, or the 12 volt power socket on a car dashboard.
The standard Mendel 12v power connector is a 3-pin XLR connector.
This picture is looking into the socket (female) and the pins (male). Pin 1 is the ground (negative) connection and pin 2 is +12v connection. Mendel has a panel-mounted male connector. The two wires from the power supply should end in a female plug that will plug into this.
You'll also need a USB to TTL converter.
Alternatively it is possible simply to buy a USB to TTL cable here. This will simplify your initial wiring up slightly, but it will mean that your Mendel will have a trailing lead. If you put a USB socket in the machine and wire it up as above, you will be able to unplug your machine completely and carry it around. You will be surprised how useful and convenient it is to be able to do that...