For backlighting purpsoe, 5V dc supply is fed to the backlight pins BL1 and BL2 (also labelled as LED+/BL+ and LED-/BL-) through a suitable current limiting resistor (for instance, with a 100-Ohm one) ...

We love the concept of using an LCD screen to transfer data. The most wide-spread and successful method we know of is the combination of a QR code and the camera on a smart phone. But for less powe… ...