Read rotary encoder from Arduino Uno in Simulink

Hello,

I can easily read the counts in Matlab (like this: https://de.mathworks.com/help/supportpkg/arduinoio/ug/control-rotary-encoder-knob.html), but not in Sumulink! Can someone tell me how it is the correct way to read the counts in real-time in Simulink?

Thanks

Answer 1

[Pranav Murali]

I understand that you are trying to read the counts from a rotary encoder using Simulink. Although Simulink doesn't have a block to interface a rotary encoder at present, it can possibly be achieved in two ways:

1. Write your code on MATLAB and import the function as a Simulink block. See how that is done here.
2. Attach External Interrupt block to pins 2 and 3 to call an Interrupt Service Routine (ISR) function. The ISR will then perform bitwise comparison of the two inputs to increment/decrement the counts.

The idea behind the second approach is to implement the rotaryEncoder function through existing Simulink blocks.

[Apostolos Vrontos]

Hello Pranav,

1. I tried to import my Matlab code in Simulink but it cannot get built, because some arduino commands are not supported in Simulink.
2. The External Interrupt can detect a change from HIGH to LOW, or the opposite, but for some reason it does not support only the LOW or only the HIGH option. I need those for defining clockwise or anticlockwise rotation, otherwise my output keeps just increasing.

Any other idea?

Thanks,

Apostolos

[Pranav Murali]

You can use the External Interrupt to call the ISR when the the signal at PIN 2 goes from LOW to HIGH. The ISR will detect the signal at PIN 3 to determine whether the encoder moved clockwise or counterclockwise based on the value. Please check the reference below which explains the working in detail:

http://www.creative-robotics.com/quadrature-intro

[Pranav Murali]

With respect to approach 1, the code involves adding a library which I failed to notice earlier. Hence the model is not getting built.

The addition of an arduino library to Simulink is done through a S-function. Developing Simulink Device Driver Blocks: Step-By-Step Guide and Examples explains the process. The file also contains the example of Rotary Encoder.

[Yugandhara patil]

Can we use the same approach for the discrete system too?

[Phan Du]

Hi! You can follow the attach file.(Version Matlab 2020a)

[Azlin Afiqah]

@Phan Du Hi, can you give me the block diagram in version R2014a. Thank you. I'm helpless doing this project. I really really appreciate your support. Thank you again <3

[Phan Du]

@Azlin Afiqah

[Azlin Afiqah]

@Phan Du Thank you so much. I really really appreciate that. Thank you so much <3

[Ghani Lawal]

If one doesn't care about the direction of the motor, can one just attach the External Interrupt to call the ISR when the signal at PIN 2 goes from LOW o HIGH?

Note: http://www.creative-robotics.com/quadrature-intro is a broken link

Answer 2

[Hasan Falah]

Hello friends,

I’m using arduino Due to read incremental rotary encoder by simulink, there is no block in sinulink to do that.

I tried with external interrupt example in matlab 2020a but it is reading only in one direction and just increasing, so it should be readings in clockwise and counterclockwise.

Aslo I tried with encoder S-Function in Device Driver examples but also does not work.

Your help please .....

Thanks

[fatima zohra soussi]

hi hasan are you did it that if yes can you help me contact me

[e-mail]

[Yago Menezes]

hi Hasan, did you manage to solve this problem?

if yes can you help ?

I am working with a 2dof helicopter plant, which uses incremental encoders and would like to interface with simulink

[e-mail]

[Harshil Jani]

Hi Yago menezes, If you are able to use it using simulink please send me to [e-mail]

[Anass Dkheila]

Hello Hasan did you solve this problem? if you did can you send it to me at [e-mail]

Answer 3

[Daniel Velazquez]

Hi, thanks for the encoder part.

Attached is a preliminary implementation of a PID Speed Controller for a DC motor with encoder.

The circuit is a low side FET to the pin 5 of the ATMEGA (PWM output) and pins 2 and 3 go to the encoders as input.

The PID parameters and scopes are tuneable.

Saludos

Daniel Velazquez

[Azlin Afiqah]

Hi, can you give me the block diagram in version R2014a. Thank you. I'm helpless doing this project. I really really appreciate your support. Thank you again

Answer 4

[Daniel Velazquez]

Hello Azlin, unfortunately I do not have R2014a but you can easily redraw it in your version from the image attached of the Simulink diagram.

Have fun

Daniel

[Azlin Afiqah]

Thank you so anyways <3

[mechali omar]

Hola, Hello Daniel Velazquez

Thank you for providing these useful files.

May I kindly ask you to provide a small clirification about some blocs in the encoder function.

1- for the gain 60/485. Why we exactly need to choose these values. Are thery related to the encoder type, or they remain valid for any other encoder.

2- for the bloc with gain of 0.1. What is the role of this bloc with exactly 0.1 gain.

3- How to change the sampling time of the S-Function block "Ts".It remains always 0.1 even we have changed it in the workspace.

GRACIAS

[Omer Faruk]

Daniel could you explain how we obtain response curve?