GroPoint Sensors topic

The Sensor and Variable objects for all GroPoint sensors.

This library currently supports the following GroPoint sensors:

• GroPoint Profile GPLP-8, 8-Segment Soil Moisture & Temperature Profiling Probe
  • GroPoint Profile User Manual, including Modbus Instructions.
  • GroPoint Profile Technical Info
  • Class Documentation

These sensors operate a 7.5 to 14.0 VDC power supply (Max 18.0 VDC). The power supply can be stopped between measurements for all. They communicate via Modbus RTU over RS-485. To interface with them, you will need an RS485-to-TTL adapter.

The sensor constructor requires as input: the sensor modbus address, a stream instance for data (ie, Serial), and one or two power pins. The Arduino pin controlling the receive and data enable on your RS485-to-TTL adapter and the number of readings to average are optional. (Use -1 for the second power pin and -1 for the enable pin if these don't apply and you want to average more than one reading.) Please see the section "[Notes on Arduino Streams and Software Serial](@ref page_arduino_streams)" for more information about what streams can be used along with this library. In tests on these sensors, SoftwareSerial_ExtInts did not work to communicate with these sensors, because it isn't stable enough. AltSoftSerial and HardwareSerial work fine. Up to two power pins are provided so that the RS485 adapter, the sensor and/or an external power relay can be controlled separately. If the power to everything is controlled by the same pin, use -1 for the second power pin or omit the argument. If they are controlled by different pins and no other sensors are dependent on power from either pin then the order of the pins doesn't matter. If the RS485 adapter, sensor, or relay are controlled by different pins and any other sensors are controlled by the same pins you should put the shared pin first and the un-shared pin second. Both pins cannot be shared pins.

By default, this library cuts power to the sensors between readings, causing them to lose track of their brushing interval. The library manually activates the brushes as part of the "wake" command. There are currently no other ways to set the brushing interval in this library.

The lower level details of the communication with the sensors is managed by the EnviroDIY GroPointModbus library