microcontroller - For a 'customized' arduino consuming less energy making use of Attiny85 vs PCB Fabrication?

Currently I am working on a prototype project where I try to move a servo (6V) according to the level of light that is recognized by a photodiode making use of the ISR function. A torch light is used as the source of light.

First, I have built this project successfully making use of an arduino uno. After that in order to reduce the energy consumption I have made an Arduino on a breadboard making use of an atmega328 microcontroller adding sleep function using the jeeLib library. It worked well. Now I want to go to the next step with this project to design the prototype into a functional tool/device.

I was planning to customize an arduino and solder the servo (6V), photodiode etc.

I have researched to on this topic and read carefully the following link (How to go from newbie to manufactured?) and learned that creating a customized arduino might emerge to be an exhausting task; especially for a newbie to electronics like me.

At the same I am wondering whether there is a way to skip going through a PCB Fabrication. Now I came to learn that I might use an attiny 85 using a perfboard that can be used to program a servo and ISR function as well. Attiny 85 also consumes less energy.

Given the fact that I 'only' need to control a servo (6V) depending on the voltage going through a photodiode I do think that an attiny85 microcontroller might be a decent way to realize my project with less effort. I am aware of the little EEPROM and Flash size. However as already once in a discussion ( My Atmega328 seems to be overkill, what should I use instead?) apparently not all program that work with arduino uno will work with attiny 85.

Can you tell me whether there is a way for me to skip working with a pcb manufacturer to finalize my project? Is using an attiny 85 microcontroller a good alternative for my project?

Answer

An attiny will be fine for a single servo and adc sensor with the Arduino firmware. The things an attiny can't do that an atmega can has to do mostly with code space and amount of timers or interrupts. Your project is very small and not affected by this limitation.

As for developing a custom Arduino pcb, it's not that complicated. An Arduino is essentially just a breakout board for the microcontroller, with a regulator and usb to serial circuit attached, neither which are 100% required to be on board. Look at various bare bones Arduino which are no more than the microcontroller and a few passives.