Quantity   Component name
1 × ATmega 328P
1 × LCD display sheild
1 × BPW-34 PiN photodiode These are really cheap silicon photodiodes that cover nearly all the visual spectrum plus a little bit of the near IR.
1 × CA3130 op amp The choice of the right op amp is really critical as discussed in one of the project logs
1 × LM9805 linear voltage regulator A buck converter can also be used provided one uses a good decoupling practices to filter out the high frequency noise. Linear regulators are a lot less noisy but not very suitable for battery powered applications