Vegetronix - Model RS232 -8 Inputs Soil Moisture Sensor Reader
This low-cost no-frills data logger is perfect for reading up to 8 Vegetronix soil moisture sensors. It reports sensor data back to a host computer via RS232, or it can run stand alone and store data to non-volatile memory, for later retrieval.
Setup is very quick, with screwless terminal blocks. It can powered with a wide supply range of 5 to 24V from batteries or a wall transformer.
Each sensor channel uses 3 spots on the terminal block: for power, ground and the sensor input. The logger will turn on power to all sensors simultaneously with a programmable setup time.
The device looks like a serial port to host PC systems so any communications software program such as HyperTerminal can be used to control it and gather data. HyperTerminal is standard to all windows systems so no additional host software need be purchased.
Data is returned in comma separated format, for easy manipulation in spread sheet programs. Here`s an example output file: LoggerFormat.txt. Just configure the Windows HyperTerminal program to save data to a text file. You can specify unit labels for each channel, and each channel can be calibrated with a 2 to 10 point calibration curve for non-linear devices.
The logger can be used with sensors other than our soil moisture probes, so long as the sensors output less than 3.3V. For sensors with a higher output voltage, a simple resistor divider can be used to scale the voltage to appropriate levels for the logger.
The logger normally consumes only 85uA when it is not sampling data, so it is perfect for battery powered applications.
Applications
- Sprinkler and irrigation systems.
- Green house irrigation systems.
- Home automation systems.
- General purpose data logging.
Features
- Monitors up to 8 sensors.
- Streams data to a PC, or saves to internal non-volatile memory.
- Real time clock.
- Low power for battery powered operation.
- Low cost.
- Compact.
- Screwless terminal blocks.
- Flanged box for easy wall mounting.
- Upgradeable firmware through RS232 port.
- Each channel can be calibrated with up to a 10 point curve.
