nrf_gfx_bmp565_draw

[lydie]

Hi,

I would display a picture on my lcd screen. I use the driver st7735, with PCA10040 and my IDE is segger embedded. I find the documentation of nrf_gfx_bmp565_draw: 

​

ret_code_t nrf_gfx_bmp565_draw	(	nrf_lcd_t const *	p_instance,
		nrf_gfx_rect_t const *	p_rect,
		uint16_t const *	img_buf
	)

I don't find example with it.

I don't understand the last parameter: [in]img_buf Pointer to data from the .bmp file, because I don't know how can I have a pointer to data. 

In my code, I opened a picture with fopen, and I read this file with fread. I thought img_buf  was the result of fread, but no, it doesn't work or it displays anything. Here is my code

char * img_file ="../../../../../../couleurs.bmp";
char buff_img[100];
uint16_t img_size;
FILE * img = fopen(img_file, "r");
img_size = fread(buff_img, sizeof(buff_img), 1, img);
APP_ERROR_CHECK(nrf_gfx_bmp565_draw(p_lcd, &rect_img, img_size));

So i would like to have more information about nrf_gfx_bmp565_draw to understand how to use it.

Thanks!

[lydie]

Hi,

not ofter, it's to change the background. Ok thanks, I will try with this library. 

[picatostas]

it comes late but, gimp can export c code for a 16 bit bitmap. And it worked for me much better that the "Display Module" software suggested.

It exports it as unsigned char, so when using it in the gfx library you gotta treat it as (uint16_t). Colors are inverted but maybe that has to do with the endianess of the bytes? I don't know for sure.

[ovrebekk]

Hi 

In recent times I have had a lot of success with this converter also.

It is made specifically to be used with the LVGL graphics library, but it should work fine with other libraries also.

Best regards
Torbjørn