Undeclared identifiers in tdisp_lld.c

motley
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Joined: Fri May 10, 2013 3:51 pm

Re: Undeclared identifiers in tdisp_lld.c

Postby motley » Mon May 20, 2013 9:19 pm

Hi Joel,

I did that - took the STM32f4 demo - no changes just amended the makefile for GFX, however I didn't get a sensible lcd output. It was a combination of garbled output and no response to the home or clear commands.

I changed the main.c around a bit to set up a pattern I could recognize and tried to watch the output. I am fortunate enough to have a pc based oscilloscope one of these http://www.bitscope.com/product/BS325/ which has a logic analyser function. I can see a fluctuating 'E' enable line (correct) but also the RS line has the same pattern with a variable delay (incorrect).
The RS line should only change when the output changes from command to data and back again.

This led me to wonder if part of the 'standard' demo was also outputing to the same GPIO port - hence my desire to trim out the bits of the demo I didn't need.

I have tried 3 different LCD's with the same result, what I really really need is something simple that works and from which I can build - if anyone has a working LCD demo I would be most grateful.

I do appreciate all help.

Chris

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Tectu
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Re: Undeclared identifiers in tdisp_lld.c

Postby Tectu » Thu May 23, 2013 8:48 pm

Hey motley,

I have ordered a HD44870 based display so I can test the software myself and therefore hopefully help better. In the meantime you might want to take a look here and join the discussion: viewtopic.php?f=11&t=1078


~ Tectu

motley
Posts: 24
Joined: Fri May 10, 2013 3:51 pm

Re: Undeclared identifiers in tdisp_lld.c

Postby motley » Fri May 24, 2013 4:59 pm

Hi tectu,

More luck today - I was trying to use the same port for data and control (GPIOD) but that didn't seem to work. Changing control to GPIOE I now get some output to the top line. At least I now have something to work on :-)

A simple question has arisen on the way:

Using GCC and make I see that in the build directory are 5 files (.bin .dmp .elf .hex .map) - I am using the ST utility for programming the STM32f4 (because that way I can put off learning something else (OpenOCD) until later.) and this offers to use either the .bin or the .hex file to program the board - I always assumed it was the .hex file that should be used - is this so ?

I know about .dmp and .map but curious about the others.

I feel bad that you have had to go out and buy a display just to help me but I am very grateful for the help.

Chris

motley
Posts: 24
Joined: Fri May 10, 2013 3:51 pm

Re: Undeclared identifiers in tdisp_lld.c

Postby motley » Fri May 24, 2013 6:37 pm

Tectu,

End of a much better day, both lines of the 2x40 display working well - even have the custom characters working.

This is just what I need for now - if I get time over the weekend I will have a look at the 'read status/busy' command (I think that's what it is called) to avoid having to use delays.

I see you are going to do brightness control with PWM - that would be good to try sometime.

Many thanks again for your help.

Cheers,

Chris

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Tectu
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Re: Undeclared identifiers in tdisp_lld.c

Postby Tectu » Fri May 31, 2013 10:41 pm

Hello motley,

I am horribly sorry for the delay. For one, I had to deal with my final exams and for another, the order of my new display module has been screwed up and it got somehow lost.
The good news: I received my display today and I can confirm that the TDISP module is now fully functional (get the latest state of the master!). A community member made a few fixed and best of all, he contributed a nice demo showing how to deal with such a display on an F4 discovery board. He added documentation about how to connect it etc. You might want to check it out.

Let me know when there are any other issues.


~ Tectu


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