DLPU134 April 2024
3.2 MicroSD Card Formatting and Configuration
MicroSD cards shall be formatted to FAT32 to support SDHC capacities up to 32GB. Larger memory density SD cards must be formatted from exFAT to FAT32.
Each image must be a 24-bit bitmap (.BMP) file with an nHD resolution of 640×360. PNG, JPG, and other image file types are not supported by this EVM, and must be converted to BMP files before being loaded onto the microSD card. Each resulting .BMP file must be at least 691 200 bytes in size and not use any form of compression.
Example of the image properties for a compatible BMP image file:
A text file named “conf.txt” is required in the MicroSD card. The conf.txt file specifies a set of parameters for each image, such as the image file name, draw coordinates, background color, and time to display. Do not change the name of the conf.txt file because the MSPM0 specially looks for the conf.txt file at startup. If this file is not detected, or if the contents of the conf.txt file are erroneous, microSD card playback fails.
Details of the Configuration (conf.txt) file parameters:
| Keyword | Parameter | Comments |
|---|---|---|
| boot_up_mode | 1 |
1: Splash image 2: SSD (RGB_parallel) 3: DSI |
| number_of_sdcard_images | >=1 | The number of maximum supported images is a function of the 512 character array divided by the length of the entire image_names row of characters. Must be at least ‘1’or greater. |
| image_names | image1_name.bmp, image2_name.bmp, … | Image names must include the “.bmp”extension. |
| sequence_repeat | 1 | Must be a value of ‘1’ |
| number_of_sequence | 3 × number_of_sdcard_images | Indicator for the number of the sequence. Each image requires 3 sequences, thus number_of_sequence is determined by #_of_images multiplied by 3. |
| rgb_fill | R,G,B | Each R-G-B value can accept an 8-bit value to specific thebackground fill color of display before drawing image from SD card. |
| image | image_index, x_location, y_location |
image_index is the element to load from the image_nams list. x/y_location refers to the coordinates to start drawing the bitmap image (typically 0,0) |
| delay | 1000 | Delay to show the image in milliseconds from the time the last pixel of the SD card image is displayed. |
| rgb_fill | R,G,B | |
| image | image_index, x_location, y_location | |
| delay | 1000 |
This is an example of the conf.txt file contents for a four image example:
|
boot_up_mode 2 number_of_sdcard_images 4 image_names img1.bmp,img2.bmp,img3.bmp,img4.bmp sequence_repeat 1 number_of_sequence 12 rgb_fill 0,0,0 image 1,0,0 delay 1024 rgb_fill 0,0,0 image 2,0,0 delay 1024 rgb_fill 0,0,0 image 3,0,0 delay 1024 rgb_fill 0,0,0 image 4,0,0 delay 1024 |
Given the conf.txt file variables are case-sensitive, all inputs to the conf.txt file must in lower case.
The folder structure requires that the conf.txt file and the accessed imgX.bmp files are stored in the root folder of the microSD card. Here is an example of the folder structure for a four-image example:
