FAQ

My clock is 'spazzing' - resets constantly

Check C10 and the two resistors next to it.

Can I add a 'radio atomic time' module to this clock?

You can try but you will almost certainly not succeed, the multiplexing display and boost converter generate too much noise. If the module was 10 feet away it may work.

Can I add a GPS module to this clock?

Yes, we have a tutorial with our suggested method and some code.

What is the lifetime of the tube?

The life should be 10+ years. Keeping the display dim will likely extend the life. The tube will slowly get dimmer as the phosphor degrades. The tubes are 'new old stock' from around the mid 90's.

The clock is blinking once a second, is it broken?

You have to set the time, once the time is set the clock will stop blinking.

The clock 'works' but does not display the time, however the menus work.

Your crystal/capacitors are not installed properly.

The clock 'works' for some time but then stops keeping time.

Your crystal/capacitors are not installed properly.

The clock 'works', but it's -really- inconsistant at keeping time.

Your crystal/capacitors are not installed properly

How can I program the chip/firmware?

You will need a programmer such as an AVR-ISP or USBtinyISP.

You may also have to remove the tube to program it (we had to with the USBtinyISP). If you're using a USBtiny, jumper the 1.5k output resistors (check the usbtiny docs for information on how to do this). We dont guarantee that you can program the clock in-circuit so experimentation is key!

My tube isn't blue!

Some tubes may appear more cyan than blue. The apparent color of the tube changes with background, lighting, and brightness.

At low brightness, the seconds are dimmer than hours.

Unfortunately this is an effect of the way we drive the tube. It is not apparent at medium and high brightness.

This guide was first published on Mar 06, 2013. It was last updated on Mar 06, 2013. This page (FAQ) was last updated on Feb 10, 2020.