Jump to content

Removing the display from STM32F7 Discovery

Sting

By Sting
in User Projects

 Share

Recommended Posts

Sting

Sting

Posted
Posted

I took the display off from the STM32F7 Discovery that I won in the competition :) as I expect to use a much larger display.  The process is easy enough but not trivial.  

The display is attached to the board by thick two sided tape.  I used a small plastic screwdriver to split the tape by sliding the screw driver into the side of the tape.  I used a round plastic pen to force the display away from the processor board.  I do not have pictures of that process, If I do it again I will add some.  Once I got the display off I used super goof off  glue remover to reduce the stickiness of the tape.  I used a tooth brush and my finger nails to remove the glue, and it takes some time as the glue is very sticky.  I haven't removed the glue from the display at this point, I'm not sure what I will use it for.

An image after the display was removed and before I removed the tape.

stm32f7.before.jpg

What it looks like after I removed the tape.

stm32f7.after.jpg

Link to comment
Share on other sites
Joel Bodenmann

Joel Bodenmann

Posted
Posted

Very nice, thank you for sharing this!

Could you post a picture of the bare PCB once you removed the display? Would be nice to have a reference for the "connectors" that area required to hook up a different display panel. It seems like the touchscreen has a dedicated connection to the PCB that his hidden behind the flat flex cable of the display panel.

Link to comment
Share on other sites
Sting

Sting

Posted
  • Author
Posted

The touch panel is connected to the flex cable that connects the display to the board.

stm32f.front.jpg

I assume when I buy a new display it will have the same configuration and the flex cable from the display will have all of the pins needed.  I am going to buy a 50 pin zif connector and solder it to the board then I will have more flexibility with the display size I need. 

Link to comment
Share on other sites
Sting

Sting

Posted
  • Author
Posted

I can't find the pinout of the connector on the STM32F7 discovery board.    Most displays that come with a touch screen have the touch screen connector separate.  I have found some displays that have the touch screen in the same connector and they have the connector pinout but I can't seem to be sure if they are compatible with the STM32F7 board.  Does anyone know how to find the pinout of the connector on the board?

Link to comment
Share on other sites
Sting

Sting

Posted
  • Author
Posted (edited)

I tried to go to the website of the manufacturer of the display and could not find the part number.  My hope was that the display would show the pinout. 

I looked at other displays from other manufacturers that show the pinout for RGB interface and They did not match the Rocktech display I looked at.  I will look at others.  

As well, all of the boards have 40 pin RGB connectors not 50 pin, this in any case some sort of adaptation will need to be done.  If I could find the flex connector used on the stm32F7.  I'm not sure replacing the display was in the design of this board.  If anyone has any suggestions I would appreciate them.

Edited by Sting
Link to comment
Share on other sites
Sting

Sting

Posted
  • Author
Posted

The schematic files can be downloaded from:

http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32f746gdiscovery.html

I did this and there is one pdf that I can read and it tells the content of some of the pins but there is no order, it seems that power and ground are missing.

All of the other files are in schdoc format and I don't have altium installed to read them.  I will install a trial version if I have to, but would rather not.  I am a software guy, I do some vhdl firmware, but no hardware.  I have a friend that might be able to read them and generate a pdf file for me.  

Link to comment
Share on other sites
Sting

Sting

Posted
  • Author
Posted

I am trying to find a display that I can use for my projects and could use some advise.  The stm32f7 Discovery lcd pinout seems to be the standard RGB interface.  There are not many displays that have the lcd and the capacitive touch screen combined in the same RGB cable.  You will see by this post that I am really a software guy and need this to fit together fairly easily.

One display I would like to use has two pin issues.

http://www.hotmcu.com/101-inch-1024x600-tft-lcd-display-with-capacitive-touch-panel-p-215.html?cPath=6_16

The issues are: 

1)  Both pin 1 and 2 are both backlight vdd on the display and the pins on the stm32f7 are pin 1: vbl- and pin 1 vbl+.  
I don't know if it is a typo, I asked the manufacturer and they sent me the same information that is on the web page.

2) Pin 35 on the display is a pwm backlight control and on the stm32f7 the pin is GND.  
I assume tying this pin to gnd on the display would make the backlight display black.  
I asked the manufacturer about this and got no response.  Is this assumption true?

 

Link to comment
Share on other sites
  • 4 months later...
Sting

Sting

Posted
  • Author
Posted

I am back trying to figure this out and all of the displays I can find have separate rgb and touch connectors.  To really make this work, do I need to build a circuit board that on the input side has the 40 pin rgb connector and a 4 pin touch connector.  On the output side has a 40 pin rgb connector to the STM board.  The board just maps the touch connectors to the right pins from the input side to the output side?  Then I would just need a flex cable to connect from this board to the STM device.

Link to comment
Share on other sites
  • 2 years later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...