This submarine is so simple because of the use of a laminated/moulded solar module, waterproof by itself and by skipping any attempts to waterproof the connections or the motor. Don’t worry, many simple electric motors do withstand running them immersed in water. Some of them might corrode somewhat after use, making starting up the next time a little difficult, but For several this will not even be a problem
Solar powered submarine: [Link]
This ATmega48 based project involves implementing a low-cost, high-performance bipolar stepper motor driver. The driver is designed for retrofitting a piece of equipment for CNC operation with inexpensive interpreter programs. For example this board was used to control a milling machine.
Microstepping Bipolar Stepper Motor Driver: [Via] - [Download Project] - [View Project PDF]
Electronic combination lock always fascinated me since i was a kid, playing with blinking LED circuits. At that time i was always thinking on some sort of electronic combination lock that i could add to my bedroom door, but unfortunately i wasn’t working with micro-controllers at that time so it was very difficult to put together something like this. But these days you can easily build a project like this, the parts are available everywhere.
Electronic combination lock with AT90S2313 or ATtiny2313: [Via] - [Link]
The capacitance meter begins by discharging the capacitor fully. Then it charges it and waits until the voltage across the capacitor reaches 0.632Vcc. The time is then captured and the capacitance is computed using Tau = RC. A 16 bit division routine written by Andy Warren is used for this project. The result is then displayed on the LCD. The process will then repeat itself every subsequent 0.255s.
As most of the commercial multimeter’s don’t incorporate Capacitance Meter’s, this project could prove very useful to your DIY electronic projects.
Capacitance Meter: [Link]
GoldPic was in development for 24 months. The third generation design has been extensively field tested on Clifton Beach near Cape Town and is now available in semi-kit form. The machine was designed to detect coins and jewelry on the beach and in shallow water. The timing and circuitry is optimised to detect small items like coins and rings at a good depth.
The development was done as a ‘midnight engineering’ project. Published designs failed to provide the sensitivity I required to search the soft deep sand on the Atlantic Ocean beaches around Cape Town. The kit is designed to be easy to build, using readily obtainable low cost electronic and mechanical components.