myDEWCONTROLLERPRO3

A DIY project for a very sophisticated, feature rich three-channel automated dew controller, based on Arduino Nano. The controller can be operated via a Windows or Linux program, using USB or Bluetooth. An Android BT app is also available. Once configured, the controller can operate stand alone without the need for user intervention or connection to a computer.

Copyright Robert Brown, 2014 - 2021, All rights reserved

DISCLAIMER

This project is released into the public domain as is where is, with no obligation or responsibility accepted on the part of the author, for any mishaps or failures caused by this product or use of this product. Users intending to use this project or code do so at their own risk and usage of product and code is deemed to be acceptance of those risks.

In other words, the author accepts no responsibility to damage caused to any equipment or goods or self by using the ideas, schematics and code associated with this project, or loss of income or all other losses that may be incurred.

The schematic, code and ideas are released into the public domain. Users are free to implement these but may NOT sell projects based on this project for commercial gain without express written permission granted from the author

OVERVIEW

This is a very powerful, feature rich, DIY Dew Controller based on an Arduino Nano, PCB or bread-boarded and enclosed in a project hobby box. The dew controller provides numerous features not currently found in many professional systems on the market today.

SPECIFICATIONS

• Supports standard dew straps such as DEW NOT via PWM output, 12VDC
• Three independent controlled dew channels each with their own temperature probe DS18B20
• The 3rd dew channel can mimick one of the other channels, so that two dew straps can act as one to provide additional heat for a large scope
• LCD1602/LCD2004/OLED display of all settings
• Optional remote control and logging via USB
• 12VDC @ 5-8A PSU required
• Reverse voltage protection on 12VDC input
• Each dew channel powered by MOSFET transistors for greater effeciency (2.5A)
• Dew channels are PWM adjusted depending upon dew point/algorithm
• Controller automatically adjusts power to dew straps (0, 10%, 20%, 50%, 75%, 100%) as required
• Supports manual override switches to boost PWM power to 100% for each dew channel
• Supports remote control via serial port or Windows Application
• Temperature/Humidity Sensor DHT22 (support for DHT11, DHT21 and DHT22) or HTU21 I2C
• LEDS indicate if PWR is on to dew channel (brightness indicates % pwr applied)
• 12VDC cooling fan support, speed PWM controlled with RGB LED indicator
• Key session state values saved in EEPROM for later retrieval
• Three tracking algorithms, DewPoint, Ambient and MidPoint with adjustable band offsets
• Optional data logging of parameters to CSV file
• Optional calibration for each channel temperature probe
• Optional remote control via Bluetooth for LCD1602/LCD2004

DIFFERENCES BETWEEN DCP2 AND DCP3

• Version 3 adds an extra dew channel and temperature probe. This can be manually configured (OFF, 0-100%), or can mimic either Channel-1 or Channel-2
• Minimal components are required, there is a new PCB, and it may be possible to fit this to your existing v2 strip-board layout.
• Extra components needed are 1pc 1.2K resistor, 1pc 1M resistor, 1pc TIP120 transistor, 1pc RCA panel mount female, a bunch of wires and some soldering.
• MOSFET FQP30N06L for less heat and greater efficiency
• A temperature probe associated with Dew Channel-3.
• Support for HTU21D I2C Temperature and Humidity Sensor (which is very accurate, operates over a wide temperature range, and has very fast read times compared to the DHTxx sensors. An additional I2C header is provided to support the HTU21D sensor and LCD2004 on the I2C bus. A 12V LED is included to indicate 12V power ON/OFF.
• A lot of the firmware has been rewritten for myDewControllerPro3. The latest Arduino firmware v3xx is required, as well as the latest Windows v3xx application software.
• Support added for OLED.

WHERE TO FIND THINGS

Make a folder to store all the project files needed for this project, then download the following files and store them in that folder. After downloading, you will need to unzip any files that are in zip format.

Documentation
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/Documentation/

Firmware
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/CODE%20ARDUINO/

Windows application
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/CODE%20WINDOWS/

Linux application
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/CODE%20LINUX/

ASCOM Observing Conditions Driver
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/ASCOM%20Observing%20Conditions/ASCOM%20Driver/

ASCOM Driver Test application
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/ASCOM%20Observing%20Conditions/ASCOM%20Test%20Client%20App/

PCB Gerber Files, Layout, Schematic, Parts list
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/PCB%20Order/

Android Bluetooth Application
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/ANDROID%20APP%20BLUETOOTH/

** Stripboard design for those who do not want a PCB**
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/STRIPBOARD%20LAYOUT/

3D Printed Case
https://sourceforge.net/projects/arduinonanodewcontrollerpro/files/myDewControllerPro%20v300%203channel/3D%20Printer%20CASE/

ARDUINO IDE SOFTWARE

Download and install the latest version of the Arduino IDE [not the web version]
https://www.arduino.cc/en/main/software