My current project is running great and I am getting months of use ( mostly sleep) out of a single 2400ma Li Ion cell.
I want to add a OLED display(16x2 Newhaven) and apparently the display will draw about 5ma of current when it is turned off via code. This will kill my battery life.
An option is to power it via a P channel MOSFET controlled by a D pin. As it is now all my pins are driven low when asleep. But to power the display I will need to drive the pin low when awake and hi when asleep. Will this draw more power?
I have tried powering the OLED directly via a D pin ( even tried 2 paralleled D pins) but this resulted in strange readings on A pins.
Should I use the D pin to drive a N channel FET that drives a P channel FET that supplies 3.7v to the OLED?
What other options do I have?