ArDewNo

Intelligent Telescope Dew Control

  • 6 Independant channels
  • Fan or Heater mode
  • Intelligent PID loop
  • PWM output for efficiency & precise control
  • 20x4 LCD Display
  • Temperature and Humidity sensors
  • Automatically calculates optimum target temperature based on humidity
  • Open source code and communication protocol

Intelligent Control

PID loops automatically adjust the heater/fan outputs to bring your devices to the optimum temperature.

ArDewNo calculates the optimum temperature between the dew point and ambient temperature.

Safe Communications

The communications protocol uses COBS encoding with CRC32 checks to ensure any corrupted messages are discarded.

This prevents errors from being interpreted as commands that could damage your expensive equipment.

Interactive GUI

The interactive desktop software shows an overview of all inputs and outputs and plots data over time in an easy to read graph.


Output Modes

Heater

When a channel is in heater mode, it's target temperature will be calculated to be the mid-point between the ambient temperature and the dew-point.

This was chosen because:

  • Being above ambient will cause heating of the surrounding air causing turbulence and distortion in the image.
  • Being below the dew point will cause dew to form on the surfaces.

ArDewNo will only be able to raise the temperature of the channel by controling the current flow through the heater.

Fan

When in fan mode, the channel's target temperature will be set to be equal to the ambient temperature.

ArDewNo can raise or lower the temperature by controlling the fan speed to bring it closer to ambient temperature.


LCD Screen

Splash Screen

The splash screen is displayed when ArDewNo is first turned on whilst the temperature sensors are initialized.


Heater Channel Status

The view finder / guide scope has a dew heater band made with nichrome wire.

ArDewNo will control the current through the heater to bring the finder up to temperature if it drops below the target temperature.


Fan Channel Status

The primary mirror has a 140mm fan behind it.

ArDewNo will intelligently control the speed of the fan to bring it closer to ambient temperature if the temperature rises above or falls below ambient.