Hello all
I've bought a I2C/TWI Interface for my arduino lcd. I can't get it working.
I've tried all codes from this website http://arduino-info.wikispaces.com/LCD-Blue-I2C and I'm sure I've soldered the component correctly.
the best result I can get is the first line full of blocks but now text or garbled characters
So here are two possibilities, one you have a faulty device or two you are doing something wrong.
However according to you you have done everything correctly so the conclusion would appear to be a faulty device. But I think you are doing something wrong, so if you give us more detail about what you have done maybe we can spot it.
Have you tried the I2C scanner ?
Do you have 4.7 k ohm pullup resistors on A4 & A5.
Have you downloaded the NewliquidCrystal..zip file; imported these new libraries; renamed your current liquidCrystal library folder to _old and then renamed the New ones to liquidCrystal ?
I haven't renamed my folders, I simply installed newliquidcrystal
I don't have any pullup resistors installed
joerack:
I haven't renamed my folders, I simply installed newliquidcrystal
I don't have any pullup resistors installed
The folder you downloaded is called "NewliquidCrystal"
The running code is looking for the "liquidCrystal" library but the existing one is for the parallel interface.
Now you have the I2C interface you need to replace the existing library with the New one.
That web site tells you how to do that at the beginning of its page , if my previous post was not clear.
I don't have any pullup resistors installed
Did you know I2C is OPEN COLLECTOR ? (meaning it requires pullup resistors)
Some modules include them , some don't. Turn off the power and measure the reistance from the SDA pin to the 5V Vcc pin on the module to see if it has onboard pullups.
If it already has them it doesn't hurt to add them. I've found that always adding them guarantees it will work , but if you prefer to measure the resistance first that's your choice.
I installed the library with arduino's internal program that installs from zip.
That website only says I should remove "master" if the zip has this word included.
Am I missing something
Am I missing something
Pull up resistors for a start.
joerack:
I installed the library with arduino's internal program that installs from zip.That website only says I should remove "master" if the zip has this word included.
Am I missing something
The I2C/TWI board i got the other month does have the pullup resistors fitted, but as G_mike says its worth checking your model does have them.
To be sure what you have done with the libraries can you use File Explorer and go into your Arduino folder, then the Libraries and see what is listed .
I suspect you just have LiquidCrystal and NewLiquidCrystal in there - if so have you changed them over manually ?
I have both liquidcrystal and newliquidcrystal installed in manager
joerack:
I have both liquidcrystal and newliquidcrystal installed in manager
OK what you have to do, is rename liquidcrystal as liquidcrystalparallel and then rename newliquidcrystal as liquidcrystal , then recompile your code and it should hopefully run ok
ricky101: you're saying that I need to change the liquidcrystal library.
I don't understand if you're talking about the one in program files(because it's the internal library) or the library in /documents
I ran the scanner and it says i2c detected
Strictly, it makes more sense to completely remove the old dysfunctional "LiquidCrystal" library (as per the fmalpartida instructions).
I've substituted liquidcrystal from program files completely with newliquid
no dice
I've had a result of the first line with all squares... this should be a good result
maybe a resistance is really needed....
will 2 2.2k resistances inbetween sda and scl => arduino A4-A5 fix it?
Pull-ups mean - just that - they pull each line up to Vcc. Nothing between the Arduino pins and the I2c device.
If you ran the scanner then why didn't you tell us WHAT address was detected ?
That is the whole point of using the scanner.
Are there any OTHER I2C devices on your I2C bus ?
Also, does your LCD have an address switch ?
Maybe you need the Liquidcrystal_I2C library.
Did you adjust the contrast pot?
Did you install this library ?
Where are you installing your libraries ? (do you know where you are supposed to install libraries ?)
Is this the first library you have ever installed ?)(what did you rename the library to ?)
The top line of black blocks just means the lcd is powered, but nothing is communicating with it, but it also shows that you have the contrast trimmer pot in the right position,
To see if you have got the right libraries installed , go to your Arduino /Libraries folder and see if the contents of LiquidCrystal folder looks like either of these two pictures.
Also can you post a link to the actual i2C board you bought and a clear picture/s of your hardware setup might help us locate the problem.
ricky101:
The top line of black blocks just means the lcd is powered, but nothing is communicating with it, but it also shows that you have the contrast trimmer pot in the right position,To see if you have got the right libraries installed , go to your Arduino /Libraries folder and see if the contents of LiquidCrystal folder looks like either of these two pictures.
Where did that come from??
In my limited experience, it has always meant that the display is powered and the contrast is set too high.
turn the contrast pot down until you see little dots and or characters.
