CFAG12864A-TMI-V noob questions

[cosmicvoid]

Inadequate answer.... Is it connected to the MCU's reset pin, or to an I/O pin that you can use to reset the display under software control.

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[axmanjr]

I have it connected to an i/o pin

 

[cosmicvoid]

One weird solution I found was to hardwire the LCD Vdd directly to power, so that when the rest of the board is OFF, the LCD is still receiving connected to power. Is this the way it should work?

You can do that, but you shouldn't need to. Assuming the display is being reset properly, and initialized correctly, it should always work, every time. What method are you using to display text?

 

[CF Tech]

I just clicked the link under XP/Moz, opened right up . . . .

 

[axmanjr]

You can do that, but you shouldn't need to. Assuming the display is being reset properly, and initialized correctly, it should always work, every time. What method are you using to display text?

I think I have solved it for now...

Fortunately for me, my compiler comes equipped with a driver for graphic LCDs, since they all generally operate the same way. All I had to do was change the PINs. But I don't think I'm at liberty to post the code here, since it's copyrighted as part of the compiler.

One last question: should there be a noticable delay when displaying text? There's a noticable delay for me in my code. What recommended clock frequency are you guys running yours at? Or does it matter (I don't think it does, but just throwing it out there)? I'm using a 4MHz crystal.

 

[cosmicvoid]

should there be a noticable delay when displaying text?

There will be a noticable delay for any kind of data. These types of displays have a response time of 200~300 mS, depending on temperature. Even a 4 MHz cpu will update the display much faster than the LCD fluid can change polarization. If you have long delays in your code (instead of testing the busy flag), it will be a little worse.

 

[tommy12345]

The CFAG12864 has 2 controllers, for the left half (col 0-63) and the right half (col 64-127) of the screen. The CS1 and CS2 select which half of the screen you are accessing. The level is 'high' to enable the chosen half, low to disable access.

For the CFAG12864I-STI-TN, the display driver says in order to write data to Display data memory, CS1B and CS2B and CS3 have to be in "active" mode. Where CS1 = L CS2 = L and CS3 = H. This does not make sence to me for the reasons you mentioned above

 

[cosmicvoid]

When you say "the display driver says", what do you mean? What display driver?

The CFA data sheet for the CFAG12864I-STI-TN only shows CS1 and CS2; there is no CS3. So you must be looking at something for a different display.

 

[tommy12345]

S6B0107 controller data sheet. I found a link to that data sheet when viewing the CFAG12864I-STI-TN LCD. Or I am mistaken. I am able to write to the LCD and just have been ignoring the part in the doc that says "active mode."