Battery operated photo frame using the Advanced Color ePaper (ACeP™) display from Waveshare. The display has seven colors and measure 5.56 inch, 600 by 448 pixels. Overall dimensions: 125.4 x 99.5 x 9mm (WxHxD, depth includes header and display). Display usable area dimensions: 114.9 x 85.8mm (WxH). The images are preprocessed using Floyd-Steinberg dithering to reduce to 7 colors and still have a reasonable quality and stored on a SD-card. An Arduino is used to read from the SD-card and write to the display. lenna.bmp is a ready to use example image.

• 7 Color ePaper display
• Arduino pro-mini
• SD card reader (images storage)
• LDR (to not change the image in the dark)
• N-channel MOS FET (for example AO3402) (to switch off the SD card reader)
• 2x AA of 2x AAA battery holder
• 3.3 volt mini boost converter (power supply)
• Capacitor 220uF or bigger (power supply filter)
• Capacitor 100nF (power supply filter)
• 3D printed frame

To make the Adruino and SD card reader low power, remove the voltage regulator.

Pins Arduino <=> SD Card module

• 10 - CS / SS
• 11 - MOSI / DI
• 12 - MISO / DO
• 13 - SCK / CLK
• GND - GND
• Vcc - 3.3V

Pins Arduino <=> 7 color e-paper display

• 7 - BUSY
• 8 - RST
• 9 - DC
• 6 - CS
• 13 - CLK
• 11 - DIN
• GND - GND
• Vcc - 3.3V

Start GIMP and drag the image to be processed into the application.

Use the palette editor to create a seven color palette

GIMP Palatte Editor dialog

Make sure that the colors are arranged in the correct order in the Rearrange Colormap dialog.
Main menu or right click image and select

• Colors >
• Map >
• Rearrange Colormap...
• Make sure the colors are ordered as mentioned above in the color palette or the image below, and select OK

Rearrange Colormap dialog

Resize to 600 width or 448 height so an 600 by 448 image can be cropped.

Main menu / right click image and select

• Image >
• Scale Image...
• Provide width and or height
• Select Scale to apply the selection

'Shift + C' or main menu / right click image and select

• Tools >
• Transform Tools >
• Crop (Shift + C)
• Use mouse and or size and position fields
• Select Enter to apply the crop or Esc to leave the Crop menu

Main menu / right click image and select

• Image >
• Mode >
• Indexed...
• Use custom pallete
• Select the created 7 color palette
• Select Floyd-Steinberg for Color dithering
• Select Convert

'Shift + Ctrl + E' or main menu / right click image and select

• File
• Export as (Shift + Ctrl + E)
• Type a filename and give it the bmp extension
• Deselect 'run-length encoding'
• Under 'Compatibility options' select 'Do not write color space information'
• Select Export

GIMP Export Image as BMP dialog