Well it is finished!

I have uploaded a schematic and shortly will upload the sketch and if I can a short video!

To use:

You input 7 bit's of a byte (the first bit is always zero - 7 bit ascii). Essentially the bottom right will blink either a zero or a 1. When the bit you want is shown, push the button and the bit will be added to the byte being collected. When you have a full byte, it is sent out on pin D8 - any input comes in on pin D9 (I may have these reversed). As I am just using this for loopback, Instead of SoftwareSerial, I had to use AltsoftSerial which allows full duplex TX/RX.

What you send appears on the top line and what is received comes back on the line under that. Special characters are decoded to <SI> <CR> etc.

It works - and will teach you binary - but I STRONGLY suggest a ascii/binary chart will be needed in the early stages.

As I say - completely useless - but does work!

Stan