No Backlight After Waking From Standby

[dperrow]

I've moved this from the thread http://forums.lcdsmartie.org/viewtopic.php?f=5&t=2961 so I can upload the file.

This is a replacement for matrix.dll to resolve the backlight problem.

Okay here you go limbo,

some caveats:
- It's called LCDT.dll, copy it to your display folder
- Only ever used/tested on my media PC
- Scrolling doesn't look great on my display
- Limited error checking
- Use at your own risk
- Virtually no documentation

Feedback welcomed and if I get pressured I may fix some of the above.

LCDT.zip

Regards,
Dave

[Karl]

Hello!
Thanks for your efforts with your library!
I've tested it and had no problems with the backlight after hibernation or standby.
The only bug i got so far is that the slider for the contrast and the backlight both control the contrast. So there is no control over the brightness. It would be highly appreciated if you could look into that problem. It could also help if you post the source code but only if you are comfortable with it.
The brightness can be controlled with the matrix library so i guess it is not a hardware problem.

My setup:
OS: Win 7 64bit
Software: LCD Smartie 5.4.2.92 (also version 5.4.1.7 was tested with the same result)
LCD: LCD Smartie Kit 20X4 White on Blue Starter USB/UART (DE-LD021) (http://www.sureelectronics.net/goods.php?id=937)

Regards,
Karl

[dperrow]

Yep, you were correct. The brightness routine was using the contrast command. Here's a fixed version although it's untested as the missus won't give me access to the media PC.

LCDTv3.zip

Although the source isn't clean and tidy I've uploaded this as well. I used DEVC++ to compile and build it. No support, sold as seen.

LCDTv3_source.zip

Let me know if it works okay.

Dave

[Guest]

That was quick
Thanks for the fix!
The brightness slider works now fine but is inverted in comparison with the contrast slider (and the setting with the matrix plugin).
The max left setting is off and the max right setting is full backlight. The contrast slider is as already said the other way around but that is no real issue.
Thanks again.

Regards,
Karl

[dperrow]

Karl,
it's easy enough to fix but which one is operating correctly Brightness or Contrast? Assuming the contrast is right here's the correction for the brightness.

LCDTv4.zip

Simply a matter of using 255-brightness rather than just brightness.

If they are both wrong noe let me know and i'll change it tomorrow night (off to bed now).

Dave

[Karl]

Sorry for my sketchy description but you got it right. So no more complaints by me
Thanks!

Regards,
Karl

[PvreHaavok]

It didn't work with a Sure Electronics 4x20 USB module. For the second time I started LCD Smartie, the screen stucked at dark and became unresponsive to the commands of turning on and off.

I think it's just with me, so I'll wait for an updated matrix.dll. BTW, great work.

Cheers

[dperrow]

you might find that if you go into setup and change the brightness/contrast sliders it'll start working.

Dave

[dperrow]

Hi,
Thanks to help from Bobby I've managed to fix a bug with suspend resume where the display sometimes would not clear on shutdown and will display random characters and leave the backlight on. I suspect this is the original issue with the matrix orbital dll but don't have a development environment which would allow me to try the fix in that. If anyone has, please feel free to try it. The problem is that the dll closes the communications before the USB driver has completed the transfer so random characters end up on the display. I suspect this is peculiar to specific USB to Serial drivers but don't know which. Anyway the solution is to include a delay after the last character is sent but before closing the device. I've updated the dll and attached it below:

LCDT.zip

Regards,
Dave