Want to show your own photo or graphic on a Crystalfontz ePaper display? This guide walks you through resizing your image, converting it with the image converter, dropping the data into your sketch, and fixing any orientation or color issues along the way.
Step 1: Resize Your Image
Open your photo in Paint (or any image editor) and resize it so the pixel dimensions exactly match the resolution of your display. For example, a 152×152 ePaper needs a 152×152 pixel image. Then save the image as a 24-bit BMP file. The converter needs this format to work correctly.
Step 2: Load the Image into the Converter
Click the Browse button and navigate to the location where you saved your resized image.
Step 3: Choose the Correct Color Settings
Select the settings that match your ePaper display type:
- Black and white ePaper: Choose 1-bit for Black/White.
- Grayscale ePaper: Choose 4-bit for Black/White.
- Black, white, and red ePaper: Choose 1-bit for Black/White and 1-bit for Red.
- Black, white, and yellow ePaper: Choose 1-bit for Black/White and 1-bit for Yellow.
The red and yellow settings only apply to displays that include those colors. If your display is black and white only, leave them unselected.
Step 4: Convert the Image
Click Convert. Once the conversion finishes, open the output file and copy all of the image data.
Step 5: Update the Image Header File
Open the images_for_CFAPxxxxxxxxxx.h file in your sketch and replace all of the existing image data with the data you just copied. Be sure to keep the #ifndef and #define lines at the top of the file and the #endif line at the bottom. For example, with the CFAP152152C00154 the file should be structured like this:
#ifndef IMAGES_FOR_CFAPxxxxxxxxxxxx_H
#define IMAGES_FOR_CFAPxxxxxxxxxxxx_H
// Paste your converted image data here
#endifStep 6: Upload
Click Upload to compile and send the sketch to your board. Your image should now appear on the ePaper display.
Troubleshooting
Image Is Mirrored Left to Right
If the image shows up the wrong way, you can change the direction the display draws the image. The green arrows in the converter show which direction the scan starts from. In the first set of arrows, the left option starts on the left and finishes on the right, while the right option starts on the right and finishes on the left. If your image is mirrored left to right, switch to the other option, then repeat Steps 4 through 6.
Image Is Mirrored Top to Bottom
If the image is flipped vertically, use the next set of arrows. The left option starts at the top and ends at the bottom, while the right option starts at the bottom and ends at the top. Switch to the other option, then repeat Steps 4 through 6.
Colors Are Inverted
If dark areas of your photo appear white on the ePaper and white areas appear dark, check the Inverted box, then repeat Steps 4 through 6.
Example: Mirrored and Inverted Images
Here is an example of the same image shown correctly, mirrored left to right also inverted, so you can see what each issue looks like on the ePaper display.
Jeffrey Nystrom is an engineering technician at Crystalfontz. He graduated from ITT Technical Institute of Technology with his B.S. in Electronics Engineering. In his position, Jeff engages in customer technical support, works on engineering projects, and supports Crystalfontz’s manufacturing operations. Outside of the office, Jeff enjoys working in his shop, tinkering with his 3D printer, and going on new adventures with his family.