Hey! I actually own a "DFRobot I2C / TWI LCD1602 Module"
http://www.robotshop.com/productinfo.aspx?pc=RB-Dfr-69&lang=en-US
wich it comes with the "DFRobot I2C LCD Backpack"
http://www.robotshop.com/productinfo.aspx?pc=RB-Dfr-145&lang=en-US
I would like to know wich is the easiest way to fix the BJT issue in this case. Any one can confirm that the 'A' of diode will be set on BT (P3 of PCA8574) and the 'K' on the base of BJT thanx in advance