I2c display for Martin s S/C Tx

[Martin]

Continuous buzzer is most likely because the sketch thinks the battery voltage is too low. Does the display show 'Low battery' on the top line?

Once you can navigate the menus you can adjust the alarm level. Until you have an encoder, you can navigate the menus in a rough and ready way by dabbing wires from A0 and/or A1 to GND - but it will be a bit hit-and-miss because of the contact bounce.

[chlluk]

Yes it does quote low battery. With luck the postman will drop something through the door tomorrow.
Thanks
Clive