Demo here: https://youtu.be/2e9k9ljJJ7s 

Requirement:

  1. A Digole color serial display module with Flash chip and V3.9B firmware(if your display is V3.5B/V3.6B/V3.7B/V3.8B, you can upgrade it to V3.9B by yourself)
  2. An USB to UART adapter
  3. Coolterm software for computer, download here
  4. Photos you like

Flash memory arrangement, 0~5K for welcome screen, for each 320x240 262K color photos, each photo neet 231K flash memory, the photos data start at: 5K, 236K,467K, 698K, 929K, 1160K, 1391K, 1622K, 1853K on 2MB flash, can store 9 photos.

1) Write a welcome screen which can call each image display commands set, then delay a period, at the end of welcome screen, add run welcome screen command, then the module can repeat to display all photos:

CL FLMCS\x00\x13\x88 DLY\x70 CL FLMCS\x03\x99\xE0 DLY\x70 CL FLMCS\x07\x20\x38 DLY\x70 CL FLMCS\x0A\xA6\x90 DLY\x70 CL FLMCS\x0E\x2C\xE8 DLY\x70 CL FLMCS\x11\xB3\x40 DLY\x70 CL FLMCS\x15\x39\x98 DLY\x70 CL FLMCS\x18\xBF\xF0 DLY\x70 CL FLMCS\x1C\x46\x48 DLY\x70 DSS1\xFF

Copy the above string to the tool: http://www.digole.com/tools/Convert_C_Format_String_to_Array.php, then click "Submit", then click "Download Data" to save it as binary file, the data length is 158 bytes (\x9E).

Connect the Coolterm with the Digole display, type "53 53 53 00 9E" on hex mode ("SSS\x00\x9E), then use "Send Textfile" to send the welcome screen binary file which just saved above.

2) open http://www.digole.com/tools/PicturetoC_Hex_converter.php, choose a photo, set display position X=0, Y=0,  (PLEASE SHRINK PHOTO TO 320X240 FIRST, other wise, our online tool may crashed), select use for "262K color", input address in flash for this photo, the address for first photo here is 5000, and the 9th is 1853000. Click "Get C string", click "Download data as Command set" will save to a binary file.

3) in Coolterm, use "Send Textfile" to send the photos to module, after all 9 photos downloaded, recycle the display power, you will get a digital photo frame.

Note, if you want to speedy the download, the module can save data at UART 57600 bps, use "SB57600" when you first connect the Coolterm and display (9600bps), then hit return key, then change the BAUD to 57600 in Coolterm.

if you want to interrupt the photo frame, just send any data to the serial port, the display will exit the welcome screen automatically, and now you can use it as regular Digole serial display, this function is ideal to make an animation welcome screen.

Command "DLY\x70" will delay about 28 seconds, you can change the number \x70 as you want. the step is about 0.25S.

 Attached: test file, usage: send "SSS\x00\x9E" then following "wel1" file, send "photo1" to "photo9" to display one by one