My initial plan for the TARDIS clock.



A miniature servo mounted to the roof, will pull the door open.



A standard size servo will push K-9 out through the open door, and back in again.
I will have to fabricate some kind of rail to guide K-9 -- this is the part that bothers me as I'm trying to use off-the-shelf components where possible, so that it'll be easy for anyone to replicate.

I plan to display the time on the door sign panel using a miniature OLED display.

I'll use a Raspbery Pi Zero to run everything, with either a GPS or MSF receiver to keep the time synchronised.

Craig.

Would a drawer runner make a suitable rail/track for K-9. I think you can get them in plastic which might allow you to cut it to size?

Hi Mark,

Thanks for the cracking suggestion -- I'll look into this!

I'm hoping to keep the final size about the same as a typical 'carriage clock' that would sit on a mantlepiece.

Best regards,
Craig.

Micro and standard-size servos next to each other. The standard one looks HUGE!

OLED display which is a nice size. However, when un-powered it's almost black which will look naff.
If I use a miniature e-ink screen instead (like Kindles use) then if the device is shut down* it can send an image of the TARDIS's sign to the screen which will persist even when the power is off.

*The device will be controlled by a Raspberry Pi.

I've been working on an urgent project which is time-based.

The small board shown on the right (Wemos D1 mini Pro ESP8266) has enough grunt to run everything required AND connect via WiFi to retrieve accurate time.

I found some C-code for running the clock in an Instructable, which I'm adapting. This should save a good deal of space versus a Raspberry Pi Zero.