Libelium library

It is mandatory to include the 4-20 mA library when using this board. The following line must be introduced at the beginning of the code:

#include <currentLoop.h>

Waspmote's API 4-20 mA files:

  • currentLoop.cpp

  • currentLoop.h

API's functions

Public functions:

Action realized:

uint8_t ON(uint8_t powerSupply)

Powers on the 4-20 mA supply (5 V or 12 V)

uint8_t OFF(uint8_t powerSupply)

Powers off the 4-20 mA supply (5 V or 12 V)

int readChannel(uint8_t channel)

Gets the sensor value in integer format

float readVoltage(uint8_t channel)

Gets the sensor value as a voltage

readCurrent(uint8_t channel, float offSet)

Gets the sensor value as a current in mA and introduce an offSet correction factor

float readCurrent(uint8_t channel)

Gets the sensor value as a current in mA

uint8_t isConnected(uint8_t channel)

Checks if the current loop is well connected

When using the Plug & Sense! 4-20 mA model, the correspondence between the board channels and the external sockets is defined like this:

  • channel 1 → socket A

  • channel 2 → socket B

  • channel 3 → socket C

  • channel 4 → socket D

This way, a Plug & Sense! user with a sensor on socket A (channel 1 of the 4-20 mA sensor board) will use the next line to read it:

int value = currentLoopBoard.readChannel(SOCKET_A);