The digispark is an arduino, just with less pins...
The LCD from Digispark has the same pinout as the thing you pictured, see:
https://s3.amazonaws.com/digistump-reso ... 7e_lcd.pdf
Pins 1 + 3 on JP3 is the digispark 5-pin connector
Pins 1 + 2 on JP1 is the LCD's 4-pin connector
Pin 1 = SCL
Pin 2 = SDA
Note pin assignements on the Digispark may be different then the numbering scheme your used to on "big arduino" See:
https://s3.amazonaws.com/digistump-reso ... ematic.pdf
Also, note this confusing page:
http://digistump.com/wiki/digispark/tutorials/modelbi2c
...about some very early digsparks where the LED causes problems with I2C devices
Lastly, could this be a timing issue?
See:
http://digistump.com/wiki/digispark/tricks
I have digispark's driving the RGB Led strips from adafruit (
http://www.adafruit.com/products/1461 ) no problem, although with an external 5v supply (not the USB's 5v !!) but I read somewhere these strips were dependent on the 16Mhz as well?