STM32F411 Disco incompatible with STM32F4DIS-LCD?

Hello Richard,

You need a processor with an LCD controller to operate this display.

There is no way it could be bit banged - look up the spec of typical 320 x 240 LCD s with parallel RGB interfaces to get an idea of the timing involved.

MK

Hi Michael,

Thanks for the insight and the confirmation.

Just to clarify, is the integrated SSD2119 controller on this module insufficient?

The timing on the data sheet for 16 bit parallel 8080 mode only shows minimum time constraints - I have looked at a couple of examples for similar controllers but still only get lower limits

Am I missing something?

Cheers

Rich

I looked at the published schematic for the STM32F4DIS-LCDSTM32F4DIS-LCD and there is no SSD2119 controller - can you post the schematic you are using - or a link.

MK

Hi Michael,

I am going from the datasheet

Link below

http://www.farnell.com/datasheets/1671831.pdf

Same information given in the product link below

https://au.element14.com/stmicroelectronics/stm32f4dis-lcd/module-3-5inch-lcd-f4-discovery/dp/2250207

I am not sure if the product has changed, but as far as my knowledge goes these features are included

Thanks

Rich

This is confusing !

The Farnell datasheet is useless - no schematic.

Googling for schematics finds them in odd places.

The LCD connector on the main board doesn't quite match with the LCD display.

I've attached the .pdfs I found.

I agree that the 2 page flyer on the board set talks about about the display having the driver IC ??

My guess is that they made more than one - can you get a schematic of the display baord you have (and does it have the SSD2119 vivisble)

If it does have the SSD2119 you should be able to drive it.

MK

Attachments:

	STM32F4DIS-BB REV1.0.pdf
	STM32F4DIS-LCD_REV1.0.pdf

These are the same schematics I was able to retrieve

Agree, the 20 pin DIP on the LCD schematic you have provided is quite confusing.

It highlights both RGB and 8080 interface pins

However, the other connector on this schematic has 4 pins PS[0:3]

These pins match the mode selector pins for the SSD2119 - specifically for a 16 bit 8080 parallel interface

Cheers

Rich

I think you may be right - I was thrown by them labeling the data pins as R,G, B.

Have you tried running (or looking at) the example code - it would be worth looking at it because it is very hard to work out all the settings for the display controller.

Bit banging could work - you'll need to be careful with timing - GPIO pins set for max speed to try to meet that 4ns max rise and fall time but watch out for some of the min times which the processor can easily beat.

MK

I think you may be right - I was thrown by them labeling the data pins as R,G, B.

Have you tried running (or looking at) the example code - it would be worth looking at it because it is very hard to work out all the settings for the display controller.

Bit banging could work - you'll need to be careful with timing - GPIO pins set for max speed to try to meet that 4ns max rise and fall time but watch out for some of the min times which the processor can easily beat.

MK

All good - it happens to the best of us

I have actually had a crack at the example code, albeit I wasn't trying very hard. I started second guessing the viability of bit banging - I have a rough template which uses the same commands. I figured I could get it to just turn on then I could start experimenting with different commands or I could build a command set from the example code

 

Bit banging could work - you'll need to be careful with timing - GPIO pins set for max speed to try to meet that 4ns max rise and fall time but watch out for some of the min times which the processor can easily beat.

It's awesome you say this - I figured if something is going wrong it's definitely with the timing but I wanted to ensure that I was on the right path. I will try to get this thing to startup

Many thanks

Rich