readVoltage

R2026b

Read voltage from analog pin on Arduino hardware

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Syntax

voltage = readVoltage(a,pin)
voltage = readVoltage(___,Name=Value)

Description

Add-On Required: This feature requires the MATLAB Support Package for Arduino Hardware add-on.

voltage = readVoltage(a,pin) reads the voltage on the specified analog input pin on Arduino® hardware.

example

voltage = readVoltage(___,Name=Value) specifies additional options using one or more name-value arguments. You can use this syntax only when you connect the Arduino hardware to your computer over USB. (since R2025a)

example

Examples

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This example uses:

Open Live Script

Create an Arduino object and read voltage from analog input pin.

a = arduino;
readVoltage(a,'A4')
ans = 
1.0606

Since R2025a

This example uses:

Open Live Script

Create an arduino object and read the voltage from an analog pin for a given number of samples at a specified sample rate.

a = arduino("COM24");
readVoltage(a,"A3",NumSamples=5,SampleRate=200)
ans = 5×1

    3.2551
    3.2551
    3.2551
    3.2600
    3.2551

Since R2025a

This example uses:

Open Live Script

Create an arduino object and read the voltage from an analog pin for a given duration and at a specified sample rate.

a = arduino("COM24");
readVoltage(a,"A3",Duration=0.2,SampleRate=50)
ans = 10×1

    3.2502
    3.2551
    3.2551
    3.2551
    3.2551
    3.2551
    3.2551
    3.2551
    3.2551
    3.2551

Since R2025a

This example uses:

Open Live Script

Create an arduino object and read the voltage from an analog pin for a given number of samples. Return the read voltage as a matrix.

a = arduino("COM24");
readVoltage(a,"A3",NumSamples=5,OutputFormat="matrix")
ans = 5×1

    3.2551
    3.2551
    3.2551
    3.2551
    3.2551

Since R2025a

This example uses:

Open Live Script

Create an arduino object and read the voltage from an analog pin for a given duration and sample rate. Return the read voltage as a timetable.

a = arduino("COM24");
readVoltage(a,"A3",Duration=0.1,SampleRate=200,OutputFormat="timetable")
ans = 20×1 timetable
        0 sec    3.2551
    0.005 sec    3.2502
     0.01 sec    3.2551
    0.015 sec    3.2551
     0.02 sec    3.2502
    0.025 sec    3.2551
     0.03 sec    3.2551
    0.035 sec    3.2551
     0.04 sec    3.2551
    0.045 sec    3.2551
     0.05 sec    3.2551
    0.055 sec    3.2551
     0.06 sec    3.2551
    0.065 sec    3.2551
      ⋮

Input Arguments

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Arduino hardware connection, specified as an object. Use the arduino object to create the connection.

Analog pin number on the physical hardware, specified as a character vector.

Note

If you connect to the ESP32 board, the pin number must always correspond to a digital pin. For details, see Pin-mapping for ESP32 Boards.

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: readVoltage(a,pin,Duration=0.1,SampleRate = 200,OutputFormat=“timetable”)

Since R2025a

Number of output sample voltages, specified as a positive integer.

NumSamples cannot be greater than 1 if:

  • You set the TraceOn property of the arduino object to True.

  • Arduino hardware communicates with the host computer over Wi-Fi® or Bluetooth®.

Example: readVoltage(a,pin,NumSamples=5)

Data Types: double

Since R2025a

Duration for acquisition of voltage in seconds, specified as positive number.

Example: readVoltage(a,pin,Duration=5)

Data Types: double

Since R2025a

Sample rate at which to read data from the analog pin in samples/second, specified as positive integer in the range [1, 500].

Example: readVoltage(a,pin,NumSamples=5,SampleRate=200)

Data Types: double

Since R2025a

Output format, specified as matrix or timetable.

Example: readVoltage(a,pin,NumSamples=5,OutputFormat=“timetable”)

Data Types: string | character vector

Note

You can specify the Duration or NumSamples argument, with or without the SampleRate and OutputFormat arguments.

Output Arguments

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Voltage read from an analog pin on an Arduino hardware, returned as positive number, matrix, or timetable.

Note

The readVoltage function continuously acquires data when you specify the NumSamples, Duration, and SampleRate arguments. As it is a blocking function call, MATLAB® waits until the voltage acquisition is complete and all the specified samples are collected before proceeding to the next operation.

More About

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Alternative Functionality

App

Use the Pin Explorer pane and Pin Configuration panel in the Arduino Explorer to read the voltage on the specified analog input pin of Arduino or any other supported hardware in MATLAB and MATLAB Online™. In the Pin Configuration panel, set the Mode as Analog Input (Read), and if required specify a Label to uniquely identify the pin. You can also use the plot pane of the app to interactively view data read from the board.

Version History

Introduced in R2014b

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See Also

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