photographing the International Space Station is always a fun project. there are lots of resources to help PLAN for doing this there are not many tools to help you when it is is in the SKY.

what I need is a timer specifically for the task. I’ve looked around for exactly what I need but the search has proven fruitless. an egg timer? a app timer? just an alarm? what about a sailing watch? nope. nope. nope. nope.

I decided to write one. from hardware. this tiny display is connect to an Arduino which has enough power to do this whole job. it looks something like this diagram.


the minutes Zarya is in the sky varies with every pass. so it has to be programmable. the times I care about when observing are:

ten minutes before
5 minutes before
1 minute
[events programmed] -by that star
-brightest or highest point

the displays should change depending on the position of the space craft. detailing what might be important to me as a photographer during that time. it goes quickly. interacting with this information has to be passive.

CAMERA controller I/O
ZARYA clock can control cameras remotely or wired. the event “IN THE SKY” starts the camera either tethered, sync’d via a wireless module (bluetooth, 27MHz, other), IR, USB via CHDK.

audio feedback could prove to be more helpful than visual. simply BEEPing might be enough. although specific sounds would be better. IN SKY. BY STAR. HIGH POINT. OVER.

a RTC aka Real Time Clock
LCD display for TIME and EVENT.
speaker / amp for BEEPs.

the display has to changes depending on what where when.
BEEP or SPEAK with specific information so I will not have to look at a display.
LARGE LED segment for count down, time, or OVER.

afterward the ZARYA clock should update itself with the next overhead event.