Design me a Product

Solar Rechargeable Small Hobby Motor Controller I need a simple electronic project designed and source of parts identified the project description is as follows: Overall Description: Small DC electric motor with included small gearbox designed to maximize torque powered by 4-rechargeable AA batteries that recharge via a small hobby size waterproof solar panel. Function: The DC motor will run until the batteries are depleted then stop. The solar panel will automatically start recharging the batteries, and when they have reached a full charge a signal will be sent to activate the motor again which will run again until the batteries are depleted. If left in the sun the system will run automatically unattended cycling between running and recharging until the rechargeable batteries can no longer take a new charge. Specs: The DC motor/gearbox can be obtained for less than $10/unit on Ebay and many other sources, 3-6 volts, 0.5kg-2kg/cm torque. On a hobby bread board mount or similar platform the whole project size should be no more than 150mm x 100mm for the electronics with an approximately 150mm x 100mm solar panel It’s no problem getting a DC motor to run on a bank of batteries. It’s no problem buying and using a small solar panel to charge batteries. The core of this project is the controller that lets the motor run the batteries down then keeps the motor off until the batteries have fully re-charged, then releases the motor to run when they are recharged. Budget: If each part is bought one by one (no volume discounts) the total cost for everything needed to make one of these projects must be less than $30 US, not including the batteries, parts shipping fees or taxes. Estimate: The motor/gearbox is $10, breadboard $5, solar panel $5, so I am assuming controller parts or $10. Milestone 1: Come up with a prototype parts list but hold back the parts specifications and links and I will release $80 for parts and shipping. Although the final project should cost $30/per unit for parts I assume that the prototype will take additional parts as the developer experiments to get it working, so an additional $50 for more parts has been added to milestone one. Milestone 2: $100 when the designer builds a working prototype shown functioning properly on a video clip. The clip will include the motor running and more importantly the motor automatically re-starting once the batteries re-charge. Milestone 3: $150 when the designer releases all the parts web links, written parts list with exact specifications for each part and a short video or step by step guide to building the project. Milestone 4: $70 When I have built a successful prototype, and if needed the developer answered any questions that came up during assembly.