Driving a 20x4 LCD with the raspberry pi

[meistervision]

Is it possible to drive a 20x4 LCD display with the pi using adafruit's Adafruit_CharLCD python library? I have followed the 16x2 tutorial and searched everywhere, but I haven't figured out how to write to rows 3 or 4. I can write to the first two rows of the 20x4 just fine. Any ideas/help?

[meistervision]

OK... replying to my own post . I did find some python code here that enables you to write to 20x4 displays with the Pi:

http://www.raspberrypi-spy.co.uk/2012/08/20x4-lcd-module-control-using-python/

I'm still curious if anyone has gotten the adafruit python lib to work with 20x4 displays

[dmt195]

There are methods in the library. I've just tried to go about this myself.

Under main I used the following (which worked fine):

Code: Select all

if __name__ == '__main__':
    lcd = Adafruit_CharLCD()
    lcd.begin(20,4)
    lcd.clear()
    lcd.message("Test line 1\nTest line 2")
    lcd.setCursor(0,2)
    lcd.message("Test line 3")
    lcd.setCursor(0,3)
    lcd.message("Test line 4")

[sportsnapper]

Is there any way using the library that you can get the text to scroll from left to write. I've tried some of the methods such as autoscroll(), Displayleft() and and all I seem to succeed in doing is getting a blank screen.

A working example would be great.

Or do I need to use lower level commands??

[thogue]

I am wondering the same question as above.

I actually thought things didnt work... but indeed they do lcd.scrollDisplayRight() works, but it just spends a fair share of time off the screen. Counting in my head, it took 12 shifts from when "Adafruit" leaves the screen until It came back on the other side.

Maybe we can develop a work around for this functionality.

[wormfishin]

I'm having the same problem. Were you guys able to get scrolling to work?