4x20 lcd, help me....

gud day. I am working with a serial lcd (4x20) SKD204-634 series.. Has anyone worked with this before?

the problem is that, when all the characters (4x20) are already used, I cannot clear the screen and I need to turn the lcd's power off and on in order to see the next characters to display..

does anyone have a code for clear() for this?

thank you very much

I don't know if this is what you're looking for but I used a 4x20 screen that I needed to display two menus on that a push button selected between. Whenever the button is pushed it set a variable to 1 and called the setup() function which displayed the menu according to the variable. Then when the button was pressed again, I set the variable to 0 and called setup() again to display the other menu. Good luck

When asking questions like this you are more likely to get a response if you include a link to the data sheet for the device you are using. You should also include the code that you are using and a description of what happen when you run the code.

As a last resort you can always send a string of 80 'spaces' to the display (which is what the inherent command in the LCD controller does).

Don

I had a similar issue with my 16x2 display where lcd.clear() command would not work. I solved it by setting the cursor to line 0, writing 16 spaces, then setting cursor to line 1 and writing another 16 spaces. I wrote this into a void for quick access inside of my program:

void ClearLCD() { lcd.setCursor(0, 0); lcd.print(" "); lcd.setCursor(0, 1); lcd.print(" "); lcd.setCursor(0, 0); }

Try using this. You can call on this from anywhere with in your loop by using the line: ClearLCD();

If that doesn't work you may want to see if you have a loop issue somewhere where it is actually writing your first 80 characters over and over and tries to add your additional text to the end of that.

I had a similar issue with my 16x2 display where lcd.clear() command would not work.

He's using a serial LCD so LiquidCrystal type commands are probably not appropriate.

If that doesn't work you may want to see if you have a loop issue somewhere...

That's more likely, he's probably doing something in loop() that should be done in setup(). We can't tell without seeing his code.

Don

does anyone have a code for clear() for this?

Did you check the Crystalfontz 'Display Control Codes'? Maybe this one:

\012            Control L                Form Feed (Clear Display)

Don

floresta:

I had a similar issue with my 16x2 display where lcd.clear() command would not work.

He’s using a serial LCD so LiquidCrystal type commands are probably not appropriate.

Wups, completely spaced on the serial part… I suppose it would still be possible to write a void and send the 80 spaces to clear the display if it’s not a loop issue. I have never messed with a serial interfaced LCD though so I am out of my league here lol

aphy,

Can you provide a link to the spec sheet?

Can you provide a link to the spec sheet?

The people who answer the questions have to do this themselves, it's part of the test.

Don

floresta:

Can you provide a link to the spec sheet?

The people who answer the questions have to do this themselves, it's part of the test.

Don

Only if we were selling theses parts and act as customer supports. It takes the OP a few seconds to post a link although googling seems to work, if you don't think about all the potential helpers wasting their time looking/reading and internet bandwidth doing it while the OP can just post one single link.

So FYI it's here:

http://www.crystalfontz.com/products/document/40/634v1xbrief.pdf

I can't find a manual. I bet I'm not alone.

I found the full manual, that's where I got his answer which I put in reply #5. It would be nice if he would let us know if it worked.

Don

floresta: I found the full manual, that's where I got his answer which I put in reply #5. It would be nice if he would let us know if it worked.

Don

Can you post a link? I was stuck with crystalfonts america cfa series and couldn't find the one OP has.

I went to the Crystalfontz home page and searched for his part number. It came back with http://www.crystalfontz.com/search.html?q=SKD204-634&submit=Search .

Don

Thanks. I went on their site and looked at their product list, no such part. Maybe it's an older item they no longer sell. I got the first short spec pretty easily but didn't find the full version you found. So from the full version of spec, the display has implemented several ASCII control characters, nice. It's something I am also doing.

I also suggest the OP try scroll on, scroll off, wrap on and wrap off. Would be very useful.