The StroblCap is a simple Dew Cap controller for controling two caps. The Device is a simple WEMOS D1 mini WLAN device. The communication is done via the COM port. This device behaves like a switch device. Each output channel could be set to a power output between 0 and 100%. Each channel can be equipped with a BME280 environment sensor for a automatic dew control. Each channel can be switched on and off without changing the power settings. Each channel can be switched to the automatic dew control or not.
The ASCOM driver is compiled with Visual Studio 2019 Communitiy.
A precompiled installer for x64 Win10 could be found here: Setup.exe
This package contains the ASCOM driver and the EnvironmentPlot application.
The firmware supports two environment sensors (BMP280 only) for each channel. The small BMP280 is mounted inside the dew cap near the optical surface and measure the temperature and the humidity. Out of this data the dewpoint is calculated. If the differece between the temperature and the dewpoint is less than 5.0 °C, the heater is switched on. The heater is controlled by a simple PI controler (in software) to set the power to a value to keep the 5.0 °C difference. The firmware is written in the arduino development environment.
Harware setup:
Pin D1: SCL (I2C)
Pin D2: SDA (I2C)
Pin D5: PWM for Channel 1
Pin D6: PWM for Channel 2
Please be sure to use only 3.3V for powering the BMP280. The WEMOS is not 5V tolerant!
The firmware supports following commands via serial communication line (without CR, LineFeed etc.). The general command format is "cmd:", the response to a command is always postfixed with a #.
"ID:" Sent back the device type id with "STROBLCAP#"
"S1nnn:" Set power for channel 1 to nnn, where nnn is 000 - 100 [%]
"S2nnn:" Set power for channel 2 to nnn, return "1#" when set, otherwise "0#"
"E1:" Enable channel 1. "1#" if ok
"E2:" Enable channel 2. "1#" if ok
"D1:" Disable channel 1
"D2:" Disable channel 2
"A1:" Set channel 1 to automatic mode. "1#" if ok, "0#" when no sensor was found for this channel
"A2:" Set channel 2 to automatic mode. "1#" if ok, "0#" when no sensor for this channel
"M1:" Set channel 1 to manual mode
"M2:" Set channel 2 to manual mode
"G1:" Get sensor data channel 1: "t;h;d;p#", where
t: Temperature * 100 [°C],
h: Humidity * 100 [%],
d: Dewpoint * 100 [°C],
p: Pressure * 10 [hPa]
"G2:" Get sensor data channel 2: "t;h;d;p#", where
t: Temperature * 100 [°C],
h: Humidity * 100 [%],
d: Dewpoint * 100 [°C],
p: Pressure * 10 [hPa]
"P1:" Get power value channel 1, "nnn#"
"P2:" Get power value channel 2, "nnn#"
The EnvironmentPlot application is a ASCOM client for the StroblCap device. This application can be used when your astronomy software does not support ASCOM switch devices like SGP < 4.0.
After installation of the Setup.exe file, the EnvironmentPlot application can be found in following folder: C:\Program Files (x86)\Common Files\ASCOM\Switch\EnvironmentPlot