This project uses an ATmega16 and a radio control kit to get the job done. You can control up to four servo(motors) with a simple push of a button. The system can also control a servo with a photocell, for example if you enter its range it will turn on a light. Of-course there are a few commercial alternatives but the price is quite high and many of them are not a versatile as this one.
This system is also based on the AVR Butterfly kit with two additional circuits one for ECG measurement, the other for measuring pulse oxymeter. The system can be used for monitoring ill persons or as a performance monitor for athletes. For outputting data the circuit uses RS232 or a cellphone. By using a cellphone you also get an alarm feature, so the circuit will send an alarm if any heart rate disorders appear.
This circuit based on Atmel’s Butterfly Evaluation Kit provides control on the main functions of an electroplating bath, that is the temperature and the current flow. To achieve optimum plating bot the temperature and the current flow play a major role in the electrochemical process, and they have to be kept within a defined range. Basically the controller digitally implements PID algorithms for current and temperature control.
This is one of the smallest fan controllers I’ve seen. It does the same job as others, it controls the fan speed according to a temperature sensor. The main utility is that you save power this way, and second its noise reduction, the fan will now run most of the time at lower speeds. The whole circuit its based on 3 parts:
- A MOSFET Power transistor (N-Channel), price between $1 and $2
- A 10K spindle trimming potentiometer, price around $1
- A 10K NTC temperature sensor, price around $1
These are really easy to get parts, so you wont have any trouble. As a last word this is a very useful and simple to build project. Good luck building it.
Fan Temperature Controller: [Link]
The Lux Meter is usually used to measure illumination. The illumination is how level of luminous flux is falling on a surface area. The luminous flux is visible component that is defined in radiant flux (light power) divided by relative sensitivity of human eyes over the visible spectrum. This means the Lux is well fit to light level from sense of human eyes.
However there is a difference between spectra response of ordinary silicon photo diode and human eyes, it cannot be used for the lux meter. Some photo diodes for illumination sensor have a color compensation filter on the window to correct its spectra response.
DIY Lux Meter: [Link]