There seems to be a weird obsession with super slow movie players lately. I’ve seen a few of them come scroll up my screen lately, but this one’s… Well, it kinda takes the cake, with a new frame being rendered about every half an hour. And it uses virtually no power in order to be able to do it, too. It’s based off an ESP32 in “Deep Sleep” mode and draws about 12uA (that’s 0.000012 Amps!). It’s projected that its 2,000mAh battery should last… oh, about 1.2 years.
It’s an interesting way to have a kind of constantly changing photo frame, that progresses one frame through a video sequence at a time in extremely slow fashion. One frame every 30 minutes would means that a movie like The Matrix (just the first one, not the whole trilogy) would take just over eleven years to watch in its entirety. In real-time, the duration of The Matrix is about 2 hours and 16 minutes.
It was developed by the Hackaday user likeablob, and makes use of the ESP32 module in Deep Sleep mode, only waking up as often as it needs to in order to refresh the frame – and even then it offloads most of the work to its Ultra Low Power (ULP) coprocessor. Refreshing the frame on the Waveshare ACeP 7-colour e-paper display takes about 35 seconds because e-paper isn’t all that quick to update. But what e-paper does do is hold and display an image without requiring any power whatsoever once it’s fully received it.
The slow refresh time of the display isn’t really a factor when you’re only updating the frame every half an hour or so. While playing movies on it might not really be all that practical, it does make for a neat concept as a digital photo frame that could literally run for years on a small battery without ever repeating the same image.