BRT Community

General Category => Discussion - EVE => Topic started by: riforifo on June 17, 2020, 09:40:45 AM

Title: How to check status of TFT controller IC with FT813?
Post by: riforifo on June 17, 2020, 09:40:45 AM

Hello,

Due to EMI issues, the connection between FT813 and New Haven TFT controller IC sometimes gets broken.
We end up with a black or white screen. FT813 doesn't give any errors regarging this case.

See below link for details
http://www.nhdforum.newhavendisplay.com/index.php/topic,13504.0.html

How can we handle this error?

Title: Re: How to check status of TFT controller IC with FT813?
Post by: BRT Community on June 18, 2020, 04:32:09 PM

Hello,

As Ted mentioned, it is possible that the display controller inside the LCD itself has been affected and may need resetting.

For EVE itself, you may see an error condition indicated if the REG_CMD_READ and REG_CMD_WRITE never become equal (e.g. if the device is waiting on more data to complete a command and those bytes went missing due to noise on the SPI lines).   Or if REG_CMD_READ gives an error condition (0xFFF) where bad command values were encountered (e.g. if noise corrupts the address or some data in a burst write causing a non-4 byte aligned command). Or you may also see a swap fail to complete by reading the swap register.

Therefore, it is worth ensuring you check the read and write pointers with a software timeout in case they don't become equal and a way to jump out the loop if the error condition is flagged.

You can also read back or CRC data in the RAM as well if you suspect corruption.

However, as your application is still running well in this case, it is likely that EVE is running correctly and outputting the screen on its RGB lines and that the panel itself may be affected. As Ted mentioned, additional grounding and protection against the data being corrupted may be needed to prevent it happening,

Best Regards, BRT Community

Title: Re: How to check status of TFT controller IC with FT813?
Post by: Matrix Orbital on June 18, 2020, 10:05:19 PM

riforifo,

We have done a few semi-custom displays for customers to harden displays against EMI/EMC/ESD. If you contact us we might be able to help you out.

sales@matrixorbital.ca

Title: Re: How to check status of TFT controller IC with FT813?
Post by: riforifo on June 23, 2020, 12:15:50 PM

Hello,

Thank your for your answers. I have written to the email address regarding the hardened displays against EMI/EMC.
 

About the software timeout, we have already added such a recovery case (see the below link). I would be happy if you can comment for further improvements.
.
http://www.brtcommunity.com/index.php?topic=146.0

Best Regards