Low power ePaper displays

running an esp32 display from battery long term

After experimenting with solar power over the last decade it became obvious that for some applications if you can get the power draw low enough battery power is enough to run that application for potential years. A information display would need some kind of connectivity and I had looked into running an ESP32 with low power a couple of years earlier. That time I ran into the issue that the LDO I used and that were included in most dev boards ate up about 1mA constantly and that limited the possible runtime for my projects to days on battery power alone.

Solar lights too

power managent in a simple application

While the firefly jars were nice they lacked the utility of a simple solar light. The way I had to use epoxy to fix the panels inside the jar was also a bit of an annoyance. A light would also need some diffusion to work well. I decided to trade a some of longevity for convenience and lower BOM and start using simple glass jars with metal screw tops. The glass should be milky and thus scatter the light of a few warm white LED to give the light a nice glow.

Kindle hacking

slight kindle modifications

I have been a fan of the Amazon Kindle e-readers ever since I first was able to get my hands on a Kindle 3 Keyboard. I had been pining for a way to read electronic books on something other than a computer screen for a long time. Of course what I find most interesting about the Kindle e-readers is how easy they are to root - relatively speaking of course. Some fine soldering is required.

Firefly jars

Lets build solar powered glass jars that come alive with simulated fireflys at night.

Around 2010 I started to experiment with solar power. Since outside isn’t the best of environments for electronics I came upon the idea to do a solar firefly glass. A glass made for canning food would be completely moisture resistant and stable. Along the way I learned a lot about how to harvest energy from the environment and most importantly that hot-glue will melt inside a glass yar in summer.