How to increase processing speed of disital input using Arduino

Question

Yuta Hanazawa 2020-2-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/503676-how-to-increase-processing-speed-of-disital-input-using-arduino

评论： Walter Roberson 2020-2-4

采纳的回答： Walter Roberson

在 MATLAB Online 中打开

I want to disital input using Arduino Uno on MATLAB Support Package for Arduino Hardware

So, I made following code.

a= arduino('COM4','Uno');
tic;
for i = 1:100
    inA = readDigitalPin(a, 'D5');
end
toc

However, the processing time was very slowly at "readDigitalPin"

This code spend about 4 s.

Can I speed up the reading disital input?

Best regards.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2020-2-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/503676-how-to-increase-processing-speed-of-disital-input-using-arduino#answer_413808

You are getting about 25 Hz. Most people report that they cannot do better than about 40 Hz when using this style of interaction with arduino.

If you want something faster you will need to create code for the arduino that continually does the reading of the digital pin and sending the results back. Even if you only do that when prompted MATLAB sending something to the arduino serial port, you would get better performance; best performance would be if the arduino just continually sent data.

Note that the arduino limits the rate at which it sends serial packets over USB, and that rate is pretty far down and difficult to overcome. There is an arduino-like device that uses a different USB interface that can do better, but the device is not as flexible as arduino in other ways. USB itself limits the number of transactions per second.

USB is the wrong interface to use for real-time serial work; it is a bit better for streaming audio or streaming video, which use different parts of the USB protocol that can guarantee time allocations and bandwidth.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Yuta Hanazawa 2020-2-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/503676-how-to-increase-processing-speed-of-disital-input-using-arduino#answer_413817

Thank you, Walter.

I understood that this problem is not easy.

In this case, I select another method without connection between arduino and matlab.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Walter Roberson 2020-2-4

A digital I/O card for your system, such as from National Instruments, https://www.ni.com/en-ca/shop/select/digital-io-device can potentially get much higher rates... if you use the Data Acquisition Toolbox.

If I understand correctly, Measurement Computing makes some fairly affordable cards that could be used (again, with Data Acquisition Toolbox)

In some cases you can also do hacks such as overlaying the signal onto an audio stream and using the microphone input.

请先登录，再进行评论。