5 years, 12 months ago.

DISCO-F746NG_LCD_demo have you got it working?

I down loaded this into the MBED compiler and , compiled it and loaded it to my DISCO-F746NG and waited ...NADA ...pushed the reset ,NADA... unplugged the USB plug on ST -link port...put it back...power led is on...NADA.. .pushed reset.and ...something!.

Just trash on the screen . pushed reset and again NADA. The demo is fairly simple display some text and basic forms, if it works.

Odd thing is that LED1 should be blinking if the code is running as written... it does not light up or blink.

Any ideas??

Question relating to:

Basic example showing how to drive the LCD. DISCO_F746NG, LCD

Yes, I have loaded the latest firmware updates to the board. I also tried the simple blinky example and it does not work either!

posted by David Garrsion 29 Sep 2015

The issue is not limited to the LCD-DEMO.

see : https://developer.mbed.org/questions/60992/Downloading-or-running-compiled-code-fai/

It's the same for all code dowloaded in the 32F746-DISCO.

Using ST-LINK for restoring the original demo code (from the ST32CUBE7 package) brings back the board to its factory state (and it's ok to load your code, one time !)

posted by Patrick Pollet 01 Oct 2015

Hi, I have the same problem and I am slowly becomming desperate. First of all the original demo from ST32Cube package is working. I measured the current consumption and it is around 0,35A (with the original demo). Nevertheless I connected an external power supply which can handle 12W, but I cannot get this LCD_demo or the blink_LED project to life ?! The LCD just stays blank. I am thinking if I am doing something generally wrong ? I just included this project to the MBED compiler, hit "Compile All", and downloaded the bin file to the board using the ST-Link Utility. Any suggestions ?

posted by Henrik Meierkord 12 Feb 2016

Something might be wrong with the lower layer of mbed (in the clock initialization or something lika that) for this board, this does not work for me either. I have been able to have a blink compiled locally on my developpement system, I am going to proceed without mbed.

posted by Jose Luu 13 Feb 2016

2 Answers

5 years, 12 months ago.

Hello,

I have almost the same issue.

For me it works one time ! I compiled and load the LCD demo and it works. After that i did a small mofification to the code, compile again, load, and ..... the screen was still white, nothing happens anymore. I retried a few times with same effect. I also tried the Blink_Led and it didn't works.

(my board is updated and the driver too)

Accepted Answer

The issue is not limited to the LCD-DEMO.

see : https://developer.mbed.org/questions/60992/Downloading-or-running-compiled-code-fai/

It's the same for all code dowloaded in the 32F746-DISCO.

Using ST-LINK for restoring the original demo code (from the ST32CUBE7 package) brings back the board to its factory state (and it's ok to load your code, one time !)

posted by Patrick Pollet 01 Oct 2015

Interesting finding!!!!

See note at bottom of page 23 of UM1906. link for this .pdf is @ http://www.st.com/web/en/catalog/tools/PF261909

I was wondering what the power draw was of this board. I could not find it stated anywhere and it turns out it must be a lot as it can not be powered by a 500mA USB alone!

I did move the power supply jumper to ext 5v, connected a 5v 2 amp PS and loaded the demo again and ....IT WORKS!!!!!!!!! every time .......

go have fun as the demo graphics says....

I wish they (ST) had a note somewhere indicating this more clearly!!!

P.S. What is not clear to me is why the demo graphics shipped with the board works when the board is powered just by the USB St-Link ???????

D.G.

posted by David Garrsion 01 Oct 2015

I just measured the 5V current draw from the ext. PS and it is only 420mA. ??

This is really odd as I have a USB power meter and it indicated a draw of 300, or so, mA when the board was "trying" to run the LCD demo....

I have made numerous mods to the LCD demo code and loaded it and the board runs it very time at the end of the upload. I also inserted printf statements and they work also!

D.G.

DG.

posted by David Garrsion 01 Oct 2015
5 years, 12 months ago.

Hi!

The same happens to me!

When I compile the program give two warning messages.

I also had the warning messages, I did an update on all the libraries and .cpp and mbed-src and they (they warnings went away)

posted by David Garrsion 29 Sep 2015

it's probably because the cpp file involded is already compiled, try a "compile-all" and the warnings will be back :-)

posted by Patrick Pollet 29 Sep 2015

Right you are!

D.G.

posted by David Garrsion 30 Sep 2015