For the screen I will be using a 3.5" BW backup screen for a parking camera system.
A benefit of this screen is the small footprint of its controller board. The additional button board houses the controls to adjust the screen's brightness and contrast.
- Resolution: 320 x 240px
- Dimensions: 76 x 64mm
- Input type: Composite AV/CVBS
These boards are typically designed to be powered by an input power of 6V-12V which become a 5V and 3.3V rail respectively after passing through a series of regulators. Since I'm powering everything off of 5V, I've added the red wire on the screen's controller board to pass the 5V from the USB power directly to the 5V output of the first regulator.
After connecting the composite signal pads to the screen, I plugged in a USB charger in the Raspberry Pi Zero. The screen worked, but the image quality was terrible and contained a lot of flicker. The problem was easily fixed by hooking up a USB charger that supplied 5V at 1.5A; This was because because the raspberry and the screen consume more power than the initial USB charger could offer.
The video output by the OS will require some tweaking as a 320x240 resolution isn't much to work with: fonts are blurry and some text is just simply illegible.