Sensor acquisition developments

Cards dedicated to SDI12 sensors:

As part of the implementation of the Phéno3C platform, we deployed more than 250 sensors to track environmental variables (micro-meteorological, soil moisture content, etc.). To simplify their implementation, we have chosen to develop wireless solutions for predominantly digital sensors that meet the SDI-12 standard. 

transmitter card.	receiver for acquisition unit.	Dataloger (Campbell Scientific).

Features:

• 2-wire communication buss-1200 baud rate 1200 bauds
• Question/answer exchange protocol
• ASCII-Transfers-Up to 62 addresses per communication port
• Alarm clock of the sensors by the central measuring unit (outside the measurement periods, the sensors are switched off and do not consume electricity)
• SDI12 assets and interests:
• Digital signal (cable length, external interference)
• Sensor addressing (sensor identification)
• Number of sensors per measurement channel.
• Low power consumption of the sensors.
• Numerous environmental sensors available on the market.
• Independent standard and taken into account by many manufacturers of measuring equipment.

Other sensors:

The cards developed allow wireless acquisition of environmental data such as temperature (Thermocouple type T), radiation PAR (amorphous or crystalline silicon sensor), and the duration of dampening. It has its own internal clock, each measurement is time-stamped. They are adaptable to other types of sensors.

Thermocouple card / USB receiver

For all these cards, the acquisition can be carried out in real time either on a computer via a USB receiver, on a data acquisition unit (Campbell type) or by periodically downloading the stored data (10,000 data capacity).

Software 

Real time data display.	Card Configuration

A dedicated software program allows you to carry out the configuration of the cards:

• Setting the time
• Card number
• Type of sensors used
• Time interval (30 s to 6h)
• Associated receiver number (a receiver can manage 256 cards).

As well as data acquisition and display.

An independent Python library also allows all these features to be integrated into other software.