I had a series of different design inspirations. I really liked this girl before who was obsessed with biking, and didn't have lots of free time because of work and college. I wanted to build something she would like, and I had a FinTech Hackathon coming up. Another inspiration was Doug Costlow's bike generator. I wanted to build a way to "Make Money while Biking" and had sort of the software and hardware skills to do so.
Step 1: Attach the Stepper Motor to "Mini-Wheels"
Do this so when attached to the project box and the bike, the resulting friction powers up the stepper motor
Step 2: Attach to Project Box
So to do this, tape the stepper motor to an angle iron using strong PVC tape, then drill the iron to the top of a "project box". I got the hobby electronics project box from Micro-Center. You can optionally drill a hole for the wires to go through to be more presentable when soldering.
Step 3: The Circuit Design
I did a simple circuit design with wires attached to the ground, a small voltage regulator, and the diodes seen in the above pictures. I tested the voltage and everything before soldering.
Step 4: The Software Component
The software component required multiple things. One of them was a chip micro-controller then I flashed. The idea is that the generator powers the micro-controller and it automatically opens the mining software on startup. The other software component was a custom solidity contract I made for sort of a better variation of e-BTC. I also built a linux demon and stratum protocol to run the mining. Of-course you have the wireless component which is a private key generated in Everykey which can connect to 4G while mining.
Step 5: Connecting the Chip Micro-Controller
Connect the ends of the stepper motor to the ground of the circuit board, then have wires connected to the ground area of the chip computers. Solder everything together.
Step 6: Mount Bicycle Brackets
This step is to mount brackets to the bottom part of the project box to attach to the side of your bike.
Step 7: Optional (Add Liquid Cooling)
You can seal the project box entirely and add mineral oil for the circuits if you have the skills to or integrate mini-pc fans powered by AAA batteries as well. This is an optional step that I didn't do, but would recommend given you are doing "mining". Also keep in mind mining regularly with kinetic energy isn't very profitable, and this was done as a demonstration of a nice project that validates blocks using kinetic energy. Cryptocurrency is very power intensive and I thought this would be fun to do.