Analog Input 0-10V or 4-20mA

Description

This feature is present on OI-Mixed module (x4).

With these inputs, you can measure any voltage within the specified range. These inputs are especially suitable for applications with industrial sensors.

There are two modes available for reading industrial sensors:

Sensors with a 0-10V output
Sensors with a 4-20mA output.

It’s feasible to integrate both types of sensors, accommodating both current and voltage inputs, on the same board.

Analog input specifications
Requirements	Value	Remark
Resolution	12 bits
Sampling frequency	4.8kHz	Only ‘oneshot’ reading is supported

Characteristics

Voltage mode

You have the option to define the voltage range directly in the code.

Below are available voltage range and the precision associated. Precision is ±5 step.

Voltage mode specifications
Requirements	Value
Minimum input voltage	0V
Maximum input voltage	12V
Input impedance	1MΩ

Voltage mode available ranges
Range	Precision	Step
0 to 1.28V	± 1.56mV	0.3125mV
0 à 2.56V	± 3.12 mV	0.625mV
0 à 5.12 V	± 6.25mV	1.25mV
0 à 10.24V	± 12.5mV	2.5mV

For example, if you want an optimal resolution when reading a sensor value within the 0-5V range, it is recommended to set the range from 0 to 5.12V. This adjustment will result in improved precision compared to the default range of 0 to 10.24V.

Current mode

Current mode specifications
Requirements	Value
Minimum input current	0mA
Maximum input current	24mA
Input impedance	100Ω
Precision	±30µA
Step	6.25µA

If the input current is greater than 24mA, the module will automatically switch to voltage mode to preserve hardware.

Code examples

The example code above demonstrates how to read the voltage of an input on an OI-Mixed module.

#include "OpenIndus.h"
#include "Arduino.h"

OIMixed mixed;

float value = 0.0;

void setup(void) 
{
    Serial.begin(115200);

    /* Init AIN */
    mixed.analogInputMode(AIN_1, AIN_MODE_VOLTAGE);
    mixed.analogInputMode(AIN_2, AIN_MODE_VOLTAGE);
    mixed.analogInputMode(AIN_3, AIN_MODE_VOLTAGE);
    mixed.analogInputMode(AIN_4, AIN_MODE_VOLTAGE);
}

void loop(void) 
{
    value = mixed.analogReadMilliVolt(AIN_1);
    Serial.print("AIN_1 :");
    Serial.print(value);
    Serial.println("mV");

    value = mixed.analogReadMilliVolt(AIN_2);
    Serial.print("AIN_2 :");
    Serial.print(value);
    Serial.println("mV");

    value = mixed.analogReadMilliVolt(AIN_3);
    Serial.print("AIN_3 :");
    Serial.print(value);
    Serial.println("mV");

    value = mixed.analogReadMilliVolt(AIN_4);
    Serial.print("AIN_4 :");
    Serial.print(value);
    Serial.println("mV");

    delay(1000);
}

The example code above demonstrates how to read the current of an input on an OI-Mixed module.

#include "OpenIndus.h"
#include "Arduino.h"

OIMixed mixed;

float value = 0.0;

void setup(void) 
{
    Serial.begin(115200);

    /* Init AIN */
    mixed.analogInputMode(AIN_1, AIN_MODE_CURRENT);
    mixed.analogInputMode(AIN_2, AIN_MODE_CURRENT);
    mixed.analogInputMode(AIN_3, AIN_MODE_CURRENT);
    mixed.analogInputMode(AIN_4, AIN_MODE_CURRENT);
}

void loop(void) 
{
    value = mixed.analogReadMilliAmp(AIN_1);
    Serial.print("AIN_1 :");
    Serial.print(value);
    Serial.println("mA");

    value = mixed.analogReadMilliAmp(AIN_2);
    Serial.print("AIN_2 :");
    Serial.print(value);
    Serial.println("mA");

    value = mixed.analogReadMilliAmp(AIN_3);
    Serial.print("AIN_3 :");
    Serial.print(value);
    Serial.println("mA");

    value = mixed.analogReadMilliAmp(AIN_4);
    Serial.print("AIN_4 :");
    Serial.print(value);
    Serial.println("m1");

    delay(1000);
}

Software API

class AnalogInputsLV

Public Static Functions

static int analogRead(AnalogInput_Num_t num)

Read a voltage measure on analog pin and return the raw value.

Parameters:: num – Analog input
Returns:: Adc raw value

static float analogReadVolt(AnalogInput_Num_t num)

Read the value of AIN. The function return a float that correspond to the voltage of the AnalogInput.

Parameters:: num – Analog input
Returns:: Value of the AIN input

static float analogReadMilliVolt(AnalogInput_Num_t num)

Read the value of AIN. The function return a float that correspond to the voltage of the ANA (from 0 to 30000mV).

Parameters:: num – Analog input
Returns:: Measure in mV

static float analogReadAmp(AnalogInput_Num_t num)

Read a current measure on analog pin.

Parameters:: num – : Analog input
Returns:: Measure in A

static float analogReadMilliAmp(AnalogInput_Num_t num)

Read a current measure on analog pin.

Parameters:: num – : Analog input
Returns:: Measure in mA

static void analogInputMode(AnalogInput_Num_t num, AnalogInput_Mode_t mode)

Set Adc Mode of the given input.

Parameters:

num – Analog input
mode – Voltage or current measurement

static uint8_t analogInputGetMode(AnalogInput_Num_t num)

Get Adc Mode of the given input.

Parameters:: num – Analog input
Returns:: Mode (0: voltage, 1: current)

static void analogInputVoltageRange(AnalogInput_Num_t num, AnalogInput_VoltageRange_t range)

Set the voltage range of the given input.

Parameters:

num – Analog input
range – Voltage range (5: 0-10.24V, 6: 0-5.12V, 7: 0-2.56V or 8: 0-1.28V)

static uint8_t analogInputGetVoltageRange(AnalogInput_Num_t num)

Get the Voltage range of the given input.

Parameters:: num – Analog input
Returns:: Voltage range (5: 0-10.24V, 6: 0-5.12V, 7: 0-2.56V or 8: 0-1.28V)