Ardunio Dew Sensor

[BlueAstra]

Decided to have a look at an Ardunio for potential applications in my observatory, since the clouds seem determined to stay. I'm thinking along the lines of a dew sensor, directional cloud sensor and telescope tilt/position sensor (to check position if a motorise the roof). To get started I got a kit from Proto-Pic, along with some one-wire temperature sensors and a DHT22 temperature and humidity sensor. After the usual 'hello world' programme, I first got the temperature sensors to read out in a serial viewer. I then moved on to getting the readout on a serial LCD display. Then I integrated the Temp & humidity sensor onto the board. I added a simple dew point calculation (some are quite complex!) to get a dew point. The photo shows the breadboard setup, with the LCD showing the calculated dew point, the DHT22 temp and humidity, and the two multiplexed external temperature sensors.

I'm considering sticking the external sensors to the scope mirror edge, the DHT22 in a box along with the Ardunio and LCD display. This setup will tell me how close the mirror is to the dew point. I could extend this to control of the dew heaters to prevent dewing, and network alarms during remote control.

[Gina]

Great project Welcome to the Arduino Users Group on SGL