Undefined function 'writePosition' for input arguments of type 'double'

Hi, I have followed the guide from this page (https://www.mathworks.com/help/supportpkg/arduinoio/ug/control-servo-motors.html) on how to set up the servo motor via Arduino on Matlab.

However, I keep getting the following the error message: Undefined function 'writePosition' for input arguments of type 'double'

This page (https://www.mathworks.com/help//supportpkg/arduinoio/ref/writeposition.html) states that the writePosition function can take in any numeric value from 0 to 1, but yet the error shows up.

Why is this happening?

My code is as shown below:

Thank you.

[madhan ravi]

Do you have arduino hardware support package installed?

[Kin Sun Wong]

Hi,

Yes, I have the package installed and set up.

[madhan ravi]

which version are you using 2018a?

[Kin Sun Wong]

It's version 18.1.1

[Kin Sun Wong]

It's version 9.4.0813654. (64 bit)

[madhan ravi]

I mean which release are you using 2018 a ?

[Kin Sun Wong]

Oh yes, I am using the R2018a.

Answer 1

[madhan ravi]

change

function interval(x)

to

function interval

[Kin Sun Wong]

I have done so, but the error still persists.

[madhan ravi]

Type the below in command window:

which writePosition -all % what shows up?

[Kin Sun Wong]

Sorry, but i could not understand that.

What do you mean?

[Kin Sun Wong]

This showed up:

/Users/strider/Documents/MATLAB/SupportPackages/R2018a/toolbox/matlab/hardware/supportpackages/arduinoio/+arduinoio/ServoMotorBase.m % arduinoio.Servo method

[madhan ravi]

what's the value of s?

[Kin Sun Wong]

My value of s is:

Servo with properties:

Pins: D6

MinPulseDuration: 6.15e-04 (s)

MaxPulseDuration: 2.39e-03 (s)

[Kin Sun Wong]

However, if I were to run this code directly in the command window, it works. But it does not run properly as a function.

[madhan ravi]

uncomment the two lines before global a , see that's why global is not recommended making it harder to debug!!!

[Kin Sun Wong]

But doing so will give me the following issues, while the writePosition issue still remains.

[madhan ravi]

remove global a and global s

[Kin Sun Wong]

The error "Undefined function or variable 's'." will occur.

[madhan ravi]

how are you calling it ? by pressing the green triangle button ?can you upload the code?

[Kin Sun Wong]

Hi, thanks for the help so far.

I have reinstalled the package and the code is working again. Seems like some of the files got corrupted.

[madhan ravi]

oh good , glad that you found , anytime :)

Answer 2

[amin ali]

hello

can you help me