Two separate TFT LCD from SMT32MP1

[zveljkovic]

Hello,

Is it possible to drive two independent LCD screens from one e.g. STM32MP157? I know it has LTDC controller and also is having MIPI® DSI but I was wondering if it can run them together (no overlapping pins)?

I want  to make a product that will have one display (non touch), maybe for video output 720p - non touch; and one smaller screen 480p with touch to serve as digital buttons.  

[PatrickF · Accepted solution]

Hi @zveljkovic 

LTDC and DSI are exclusive (as in both cases, it is the LTDC who feed image pixels).

Alternative solution for a additional displays is using FMC or SPI (I guess using tinyDRM), but resolution and/or update rate would be limited (those display have usually embedded frame buffer, so refresh rate is not an issue). I think there is no possible GPU usage for those.

Regards.

[zveljkovic]

Thank you for the response. So I can drive main display with the LTDC in either RGB or DSI mode, but for second one I could use SPI. I saw here https://wiki.st.com/stm32mpu/wiki/QUADSPI_internal_peripheral#Peripheral_overview that the Quad SPI is available but it is under section Mass Storage. There are some displays e.g. here that can use QSPI. Is it possible with SMT32MP1?

[PatrickF]

Hi,

I cannot answer for QUADSPI compatibility with displays (need to get and analyze display protocol Vs QUADSPI capabilities, especially on write).
Probably possible, but we did provide only Linux MTD driver which has been tested only toward flash memories.

Regards.