Quantity   Component name
1 × Adafruit Pro Trinket 3V
1 × 16x2 LCD display
4 × Tactile button Buttons for interface
1 × Cable for camera communication Appropriate cable for your camera. I will reuse a cable form remote trigger. (2.5mm plug on one size and Nikon RS-N3 connector on the other)
1 × Transistor For triggering the shutter.
1 × Some kind of battery Not really sure what to use.