Aeon is a solar-powered colour e-ink photo frame. See the blogpost for a full write-up.
This repository contains the following design files for Aeon.
See the the blogpost for additional file downloads.
The /firmware directory contains the firmware for the STM32 microcontroller.
Before flashing the firmware, the option bytes of the STM32 must be set. Using STM32CubeProgrammer, uncheck nSWBOOT0. The option byte options should look like this:
Next, flashing the firmware can be done using the STM32CubeIDE. Your STLink programmer should be connected to the programming pins on the PCB.
The firmware includes several debugging features.
Any printf statements will be outputted to SWO, which can be read using STLink. Additionally, if debug mode is active, any logged data will be stored in an array, and written to the SD card just before going back to sleep. This debug mode is enabled by pressing and holding the refresh button to wake the device. The status LED will flash rapidly to indicate debug mode is active. Alternatively, the DEBUG_MODE_FORCE_EN flag in main.h forces debug mode to be enabled. This should be disabled during normal operation to prevent excessive SD card writes.
The BATT_LOGGING flag in logs to /logfiles/batt-charge.csv on the SD card. This only appends a new line to the file on each wake cycle, so it is safe to leave on for extended periods of time.
The ADC for the battery voltage measurement should be calibrated as the accuracy of different STM32 chips can vary. The calibration process must be done manually by changing this value in the aeon.c file.
The /image_conversion folder contains a Python script to convert images to the SLIC format, which is the image format Aeon supports.
Compile the photos you wish to display on Aeon, and save them in a directory. .jpg, .png and .heic files are supported. All images should be the same orientation. If a portrait orientation is chosen, rotate all portrait images 90 degrees clockwise.
The first step is preparing the SLIC conversion executable.
- Git clone the SLIC repository
git clone https://github.com/bitbank2/SLIC.git - Change directory
cd SLIC/linux/c_demo/ - Compile executable with
make - Copy the executable to the
/image_conversiondirectory
Next, install the required Python packages with pip install -r requirements.txt.
To convert a directory of images, run python convert.py <input_dir> where <input_dir> is the directory containing the images to convert. The converted images will be saved in a new directory named img_out.
The generated .slc files can then be copied to the /images directory of the SD card. Do not rename the generated files.
The /schematic_and_PCB directory contains the KiCad schematic and PCB design files for Aeon.