Skip to main content
Topic: My E-Paper Clock is finally complete! (Read 4496 times) previous topic - next topic

My E-Paper Clock is finally complete!

I still have to put the finishing touches on the code. Instead of having the display constantly update, I'd like to set an alarm on the DS3231 RTC to go off once a minute, and only update the display on alarm. Hopefully I'll save some battery power that way. As of now, the battery only lasts a couple of days.

I built in a USB battery charger to make it easier to charge it.

I got my PCBs in from OSHPark and put it all together in an 80mm x 80mm Sick of Beige case. Check it out!

I have a full write-up on my hobby blog. Full source is listed too.

If you want to see the project from start to finish, hit up the links at the bottom of the page.

Re: My E-Paper Clock is finally complete!

Reply #1

I'd like to see a video!

What's draining your battery? I would have thought your system would hardly draw any current except for a millisecond or so every minute when it updates your display.

Re: My E-Paper Clock is finally complete!

Reply #2
That looks very cool!

And it reminds me that I actually got a cellphone that I bought in Jan 2007 Dubai  with an e-paper display on it.  I wonder if I can reverse engineer the display, but currently I don't even know the basics of driving an e-paper display. (Edit: it's already done :-) It was a dirt cheap $40 Motofone F3 originally made for poor people in India. I bought like 20 of them and sent to electronic nerds back in Sweden.

ut it's kinda strange that the e-paper tech haven't come that much further in 6 years time....

Re: My E-Paper Clock is finally complete!

Reply #3

That's just it, the display is constantly updating. Ideally, it should only update when the minutes change. So I have to tweak the code to get it to trigger off the DS3231. Initially, I had a little trouble figuring out how to set an alarm on the DS3231 and trigger off that, but I think I figured out how to do it. I just have to implement it. For now, I just wanted to see it work.

Re: My E-Paper Clock is finally complete!

Reply #4
Does anyone know how these work?

Re: My E-Paper Clock is finally complete!

Reply #5
For the one used in the clock, I guess it's similar to these: ... ords=e-ink

This document describes how they work in detail: ... _guide.pdf

As for the phone that matseng linked to: From the picture of the PCB my guess is that the positive/negative electric field required for black and "white" is generated by applying the respective voltage to the exposed pads behind the screen.

Re: My E-Paper Clock is finally complete!

Reply #6
Oh this is really nice display and great write up about the project too! I wanted to build custom long term countdown timer/clock with 6 digit 7 segment LCD so it can go for several months on simple coin cell but it's kinda limiting to show anything more. This would have much more flexibility as to show some messages or other info.

I'd like to know how low current consumption can you get with the update once per minute?