LiquidCrystal I2C

[platypus]

The LiquidCrystal-I2C sketch wont compile and gives this error ..no matching function for call 'LiquidCrystal::LiquidCrystal(int)'

The 'regular' Liquid Crystal sketch in the same Examples folder compiles OK - no errors.

All the support .c and .h files are in the new (I2C) LiquidCrystal library folder and the regular LiquidCrystal compiles.

Any ideas?

[adafruit_support_bill]

Did you remove the old LiquidCrystal Library?

[platypus]

Yes eventually, but first I just renamed the folder and later decided to place this folder within another folder.

Then it worked as the compiler could not see it.

My bad - should have followed your notes to the letter. Thanks for your reply.

[platypus]

Do you have a method to reduce the intensity of the background light?

The Contrast only affects the characters leaving the "blind your eye" background light.

I read somewhere that pin 15 via a resistor/pot might work.

If so, can you recommend a suitable trimpot size and or procedure to effect a reduced intensity level?

[adafruit_support_bill]

You would probably need a few hundred ohms or so, depending on how much you want to dim it. It would be tough to get at on that board though without de-soldering the display. Another option would be to put it behind a smoked acrylic faceplate.

[platypus]

Thanks, that's exactly where it's going - behind dark tinted 3mm polycarbonate. However I still want to dim the backlight.

But is it pin 15 that should be broken - easy to do before assembly. The pot can be mounted between the screen and I2C pcb as I have lifted the I2C board 3mm using two short pieces of heat shrink at the end terminals before soldering from the center outwards. This also gives a nice space between the two boards.

For anyone there who is interested, I had to stop the annoying update blink screen refresh by this method - if anyone knows of another I would be interested.

In void loop()

lcd.setCursor(0,0); //sets beginning of line 1
lcd.print( your code for line 1);
lcd.setCursor(0,1); //sets beginning of line 2
lcd.print(your code for line 2);
// no more blink
Comment - this causes a refresh of each line without any blinking, giving a nice update of the sensor data.

If lcd.clear();
is used the whole display will blink annoyingly - at least with this 2 line charactor lcd screen.
With my older Freetronics lcd screens that use 6 lines there is no blinking. Different tech.

[adafruit_support_bill]

Pin 15 should work. But if it is an RGB backlight, the colors may shift a bit as you dim it. To balance the colors, you would need individual trim-pots on pins 16, 17 & 18.

[platypus]

I used the 1K trimpot that came with the white on blue 2 line character screen.

I cut the pin 15 header - as I had lifted it 3mm it was easy to just take out a piece to break the line. Then just added the trimpot across the board terminals - works perfectly.

Thanks for your help.

[zdendule]

Hallo,
Can anybody help me? I have plugged converter from I2C to 4bit for LCD, I implemented your library and compile is OK. But LCD not show characters and backlight blinking chaotic. The wires are plugged by right. Which format I must write the number of adress I2C to sketch. A7 or 0xA7? I don´t know where is problem.

[adafruit_support_bill]

Post photos showing the front and back and all your connections and we will check it out.

[zdendule]

OK, thank you. There are photos.

I2C

IMAGE_123.jpg (758.18 KiB) Viewed 403 times

[zdendule]

And second photo.

interface

IMAGE_124.jpg (807.03 KiB) Viewed 401 times

[adafruit_support_bill]

That doesn't look like one of our display backpacks.

[zdendule]

Yes, I firstly found interface on web and past it I found library for it. But during the search I found your forum.

[adafruit_support_bill]

You should contact the manufacturer. Unless their hardware implementation is identical to ours, there is no guarantee that our library will work.