unknow data when use qspi panel

[Wayne_Chang]

Hi all,

I applied QSPI driver on NCS 2.4.0  with QSPI LCD panel and I encountered the problem.

The red area is the data I sent, but the blue area is not what I sent.

I already try many way to send with qspi, like nrfx_qspi_write() or directly write to register NRF_QSPI

but all result are the same.

Is this caused by the hardware design, or can I modify it on the software side?

I already read the post below, but it seems no solution update.

 RE: NRF52840 QSPI Driver LCD（LCD Driver IC GC9C01） 

Wayne

[Kazi Afroza Sultana]

Hello Wayne,

You may try to use SPI for your LCD panel instead of QSPI?

[Wayne_Chang]

Hi Kazi,

I have previously used SPI to drive an LCD. I only began testing QSPI in order to increase the framerate. If the QSPI on the nRF52840 does not support functionalities beyond flash memory, I am considering switching to a different MCU.

However, I need a clear and definitive answer:
Is it possible to use the QSPI interface on the nRF52840 to drive an LCD?

BR,
Wayne

[Kazi Afroza Sultana]

Hello wayne,

The QSPI is created mainly to work with flash devices, and it follows a certain instruction set. If the LCD does not implement the same instruction set, you need to use regular (high-speed) SPI. 

You need to check the datasheet of the LCD to see what it supports. If it does not support the same instruction set (I think this is JEDEC), SPIM would be a better option. There is some support for custom instructions, but this would likely be slower than using high-speed SPIM in HW.