One of the projects we are currently developing is a mini dehumidifier. The proof of concept model is working well and the user interface is completed. The design is based on a Peltier thermoelectric generator and fan with micro controller precision and convenience.

The result is a superb user interface with flexibility to expand. It is intended to add USB and Ethernet interfaces to allow remote monitoring and operation.

Basic operation is as follows;

The five switches, as seen in the lower left of the picture, each with a different value resistor are read with an analog to digital converter. The switches are used to adjust the humidity and temperature set points up and down and the centerĀ  switch is on and off.

The water extraction process is based on a Peltier thermoelectric generator, a fan and a controller. Air is ducted over the coldsink to collect and remove the moisture from the air before the air is passed over the heatsink to condition the dried air back to room temperature.

The basic control and interface software for the dehumidifier were written as a state machine. Essentially simple code with a incremental timer and some flags that toggle states and see how complex one can make it.

The result is a superb user interface with flexibility to expand. The five switches, each with a different value resistor are all read through one analog to digital converter port.

The switches are used to adjust the set points for humidity and temperature and one for the on off function. The switches can be seen in the lower left of the picture.

Above is a picture showing the proof of concept prototype.