Just a quick question here if you still have everything together (backpack connected to your LCD): Did you tweak
the 10K potentiometer (It's right of the word DAT on the Backpack) to check for the display?
See the picture below with the red arrow
for the location of the potentiometer.
Turn it slowly to the left (until it comes to a stop) then SLOWLY right (DON’T FORCE turning it! -and if it stops turning try going back.)
and watch the display while you have “Hello world”
running (from the i2c/SPI LCD Backpack Tutorial >>http://www.ladyada.net/products/i2cspilcdbackpack/
) and see if that helps. You have to use those small screw drivers, like for reading glasses, to work it. Warning it's not easy- meaning you can go by where it needs to be real easy- so turn it slowly. I made the same mistake the first time- of not going slow and wondered why it didn't work. I wish that potentiometer was a little bigger.
You did say that you got the Character LCDs "Hello world"
using the examples in the regular tutorial and got that to work, right? >> http://www.ladyada.net/learn/lcd/charlcd.htm
I would like to make a suggestion here: Do baby steps next time
. Meaning Start out with the Character LCDs tutorial (http://www.ladyada.net/learn/lcd/charlcd.html
) and make sure the LCD display works with your Arduino (or whatever microcontroller you are working with) before trying out the I2C back pack. (If I understand things right you did follow this part).
THEN try out the i2c/SPI LCD Backpack Tutorial >> http://www.ladyada.net/products/i2cspilcdbackpack/ without LiquidTWI
. If you get that working then switch over to the LiquidTWI. And make sure you check that potentiometer is in the right setting before you decide things are not working.
Regarding Baby steps- I don’t know where it is located on this forum- but our Lady of adafruit
talks about breaking down your code in small steps and making sure those small parts work before you made 1000 pages of code and get frustrated about things not working. I would say that is important for wiring your circuits too. Also if things get real hairy (Meaning your getting real frustrated), set the project down for 24 hours and come back to it later.
Sleep on the problem and look at the project with fresh eyes the next day or better yet, on the week end! I can’t tell you how many times a clear head and some sleep has helped me find the error of my own ways. NOW if that does not work, ask a friend to look at your code or your wiring. You can’t always see your own mistakes; you see it as it should be. (This thought comes from a person with really bad dyslexia.)
You can even up load a picture of your project, whatever wiring diagram you have of said head ache, and the code from that project that’s helping you lose the hair on your head here so others here can take a look at it. You never know someone might see what’s wrong and give you a leg up with your project.
As Harry Potter said “Every great wizard in history has started out as nothing more then what we are *now*. If they can do it, why not us?”
Electrical Engineering is a lot like being a wizard, except we are trying to keep the blue smoke inside of the circuit.