Before spending time and money on a PCB, I built a prototype on a breadboard with an ESP32-S3 development board and e-ink module to test and develop the firmware. Fig. 1 The prototype Speeding up an e-ink display I was most excited to test the camera preview on the e-ink screen. A regular refresh takes between 0.5 s and 2 s, meaning a refresh rate of 2 fps at most. Far too slow for a viewfinder. …
The hardware for DOkA in a nutshell: Microcontroller: ESP32-S3-N8R8 Camera: OV5640/OV2640 Storage: microSD card Screen: 2.9" e-ink screen Battery charging: BQ21040 + separate power path I wanted to design a custom PCB that I could assemble myself. I only have a soldering iron, so it was important that all the components are hand solderable without any special equipment (e.g. no QFN packages). The …
Back in 2019 I went to Finland with some friends. During this trip I took photos with my smartphone camera, but also with an analog film camera. After the trip, I had the photos developed and printed. Some photos I’d forgotten taking, some photos turned out differently than I expected. The photos from my smartphone, I barely even looked at. I want taking photos to be special again, but without the …
