sendCommand

Send message to Arduino device from MATLAB

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

Syntax

[dataOut,payloadSize] = sendCommand(arduinoObj,libName,commandID,dataIn)

[dataOut,payloadSize] = sendCommand(arduinoObj,libName,commandID,dataIn,timeout)

Description

[dataOut,payloadSize] = sendCommand(arduinoObj,libName,commandID,dataIn) sends a command to the Command Handler implemented by your add-on library.

[dataOut,payloadSize] = sendCommand(arduinoObj,libName,commandID,dataIn,timeout) sends a command to the Command Handler implemented by your add-on library with a user-specified acknowledgment timeout.

Examples

Send a Command to HelloWorld Add-On

Create a command, and use sendCommand to send it to the Arduino^® hardware.

Get the parent Arduino object.

arduinoObj = obj.Parent;

Define the library name.

libName = 'ExampleAddon/HelloWorld';

Define the command ID, and create data to send.

commandID = obj.READ_COMMAND;
dataIn = [];

Send the message.

[dataOut, payloadSize] = sendCommand(obj, libName, commandID, dataIn);

Show the result in the MATLAB^® command line.

disp(char(dataOut))

Hello World!

Input Arguments

arduinoObj — Arduino object

object

Arduino object, specified as an object that is an internal variable called from within classes that derive from matlabshared.addon.LibraryBase.

libName — Name of library

character vector

Name of library defined in the custom class, specified as a character vector.

commandID — Unique command identifier

numeric

Unique command identifier, specified as a number. This number must match the ID in the command handler defined in your custom library header file.

dataIn — Array of integers

vector

An array of integers, specified as a vector. The size of dataIn is different for different boards. The below table specifies the size of dataIn for different boards :

Boards	dataIn size
Leonardo, Micro	150 bytes
MKR1000, MKR1010, MKR Zero, Mega2560, MegaADK, Due, Nano 33 IoT, Nano 33 BLE, Nano 33 BLE Sense, ESP32-WROOM-DevKitV1, and ESP32-WROOM-DevKitC	720 bytes
Uno R4 Minima and Uno R4 WiFi	512 bytes
Uno, Nano, Pro Mini, and Digital Sandbox	57 bytes

Each byte is limited to an unsigned integer between 0 and 255. Any values greater than 255 must be converted into two unsigned integers between 0 and 255, and will be sent as two separate bytes.

timeout — timeout duration

5 sec (default) | numeric

Timeout duration, specified as a numeric value that is the number of seconds to wait for an acknowledgment from the server code. Specifying a timeout duration blocks the MATLAB command line until the timeout duration is met. The default is 5 seconds if timeout is not specified.

Output Arguments

dataOut — Data returned

vector

Data returned, as an array of doubles.

Data Types: uint8

payloadSize — Length of output returned

numeric

Length of the output returned by sendCommand, as a number.

Version History

Introduced in R2015b