Custom character with Sparkfun Serial LCD

Using Arduino Displays
1

ok I can create custom characters using the LCD library with a regular LCD display
I now have to do the same thing with SparkFun Serial interface LCD

I'm sending what I think are the right data bytes

0x40 // for custom char 0
0x02
0x04
0x08
0x1F
0x08
0x04
0x02
0x00

I then try and display character 0
I get two vertical bars (seems to be the default for an undefined char)

what di I miss??
cheers
Mike

2

What is your code?

Are you useing lcd.write() or lcd.println()? the second will not work because:

  1. It will always put a newline after the characeter (which I bet is two vertical bars)
  2. It has trouble oprinting the character 0 as it usually means the end of the string (ie, you are printing and empty string).

In any case, hard to make any relevant comment unless you post code.

3

nah the issue is whether you can actually define custom chars with the serial LCD
I'm NOT using the lcd library it's a serial device

but, as luck would have it, the chars I want are already defined
so problem sorta evaporates a bit :slight_smile:
cheers
Mike

4

You should be able to use the new 'fm' LiquidCrystal libraries with a serial device. You can get them at

https://bitbucket.org/fmalpartida/new-liquidcrystal/wiki/Home

and they are a direct replacement for the libraries that are supplied wit hthe IDE download.

5

I then try and display character 0
I get two vertical bars (seems to be the default for an undefined char)

We ran into this problem a while ago and if I get a chance I will look for the thread.

As I recall, the 'solution' I came up with is to use custom character 8 in place of 0 when trying to display the character. The address 08 is what is called a 'foldback address' for address 00 (the high bit is ignored) and it bypasses whatever problem there is with using address 0.

Don

[Edit]: Here it is --> Arduino Forum