I am trying to save power by switching off graphics LCD(JHD12864E) when it is not required.
To do this I am using TIP122 as a switch. The base of the transistor is connected to a digital pin through a 1k resistor.
Collector is connected to GND of the LCD module.
Emitter is connected to Arduino GND.
Please see the diagram showing this.
I was hoping that by controlling the digital pin at transistor's base LCD can be switched off. BUT, the LCD display keeps flickering when digitalPin=1.
Is this the right way to switch off power to a peripheral device? If yes, then why is the display not stable? If not, please guide!
(Interestingly I found one guy had attempted this way...but had not succeeded either: http://electronics.stackexchange.com/questions/158096/control-lcd-with-tip121-on-arduino-not-displaying-anything)