Host Application

The software used to configure and monitor the controller runs under Windows Xp, Vista and Windows 7. The Dot Net Framework 3.5 is required to be installed.

The controller will need to have it’s device driver installed when it is first detected. The driver is located in the Drivers sub directory where the software was initially installed. Just point the driver installation process to this directory when it prompts for a location.

The user is able to change all settings for the unit on the fly, monitor all the sensors outputs, calibrate each sensor and plot all the data in realtime.

Click on the images for a higher resolution version.

Most of the screens will display a tooltip describing what each control does, so I will only skim across a few sections of the program.

Splash Screen

 

Main Screen

This is the main screen that you will spend most of the time using. When the software is running it will automatically detect if a controller unit gets plugged in or switched on. The bottom status line will indicate that the unit is connected and display the current firmware version and a few other messages. If it does not connect you can go to File -> Connect and connect manually.

Depending on what mode each output is set to will determine what the various slider bars do. Dragging these will either change the output PWM duty cycle, or a preset temperature on some of the heaters.

Clicking on Settings -> Fahrenheit Display will switch between the two temperature units. Since the sensors are actually Celcius based this mode is the more accurate.

Settings Screen

Most of the functions here have their own tooltips and are self explanatory.

If we are not using a sensor or don’t have one connected we can switch each one on or off in the Temperature Sensors area.

Temp Diff is the temperature above the ambient temperature or dew point temperature, depending on the mode set, that we will heat the heaters. If we set the one heater to Dew Point mode with a Temp Diff of 2 and the Dew Point is calculated to be 15 then when the heater gets to 17 (15+2) it will switch off. Obviously if it gets below 17 it will start heating itself again.

PWM Gain is used to set how rapidly we try and heat up each heater. Setting it higher makes it try and heat up quicker. My tests have found that leaving it at the default value works fine.

The rest of the settings should be self explanatory.

To update the settings to the unit we click on Save Defaults.

To set the settings back to the original values click on Reset Defaults. We will have to save them to the controller afterwards though.

Calibration Screen

Here we can calibrate each sensor. The temperature sensors most likely will be pretty close. The humidity sensor can be out by quite a bit initially.

For the temperature sensors select the sensors radio button we want to change. The sensors are numbered  from 1 to 4, with 4 being the ambient temperature sensor. Click and drag the top slider to  display the correct temperature, the temperature that the unit reports is set on the lower display. Once set click Calculate. It will display a message asking if we accept the new value. If we reply yes it will update the  controller with the new value. We can repeat this process with the other temperature sensors.

The humidity sensor can be calibrated two ways, using either a single point or two point calibration. I have found that a single point should be good enough. We will need to compare what value the unit reports to what another Humidity device gives as the correct value. We enter the correct value under the Actual Humidity section and the value the unit reports under Measured Humidity. We can click the corresponding Calculate button which will display another message box. This one is important, it will display the old zero point value as a number somewhere close to 300, as well as a new zero point. We must make sure that the difference between them is not much larger than about 30 or smaller than -30. The manufacturer claims a variance of about +-20.  If it does then we either have made a bad measurement or that the sensor might not be working properly.

We can also correct for the slope of the sensor, default it is 0.6pF per 1% humidity. This is done using a two point calibration. We take two measurements quite far apart, at least 50 between values, at the upper and lower end of the scale. The lower measurements are entered in the top section with the lower section for the higher readings. We then click Calculate and receive another message box. Again check the zero point difference but also check what the slope value is, it should be very close to 0.6, anything over about 0.7 or under 0.5 indicates a problem.

I would do a 1 point calibration first, try and measure when the correct humidity is around 50%. I leave the unit to stablise itself for at least 30 minutes before trying a calibration.

We can always reset the humidity parameters to defeault by clicking the Reset button.

Graph Screen

We can display the graphs by navigating to View -> Show Graphs. This screen does not need any explanation and you can explore it for yourself.

Finally we can switch to night mode under View -> Night View. All the screens should turn red, except the graph screen which unfortunately I have no control over as it is a third party plugin.

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