SPI mode and bitrate cannot be changed in Arduino DUE

Question

Massoud Tohidian 2019-8-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/475008-spi-mode-and-bitrate-cannot-be-changed-in-arduino-due

评论： Massoud Tohidian 2019-8-13

I'm using MATLAB R2016a with Arduino DUE. When a SPI device object is created using spidev, it cannot correctly change SPI mode and bitrate. Mode is alway 0 and bitrate is always 4Mbps. I have tried this also with R2019a and it is the same.

For example, I try to use this command to change Mode to 3 and bitrate to 1Mbps:

spidev(a,'D10','Mode',3,'Bitrate',1000000);

But it does not change anything there.

Is there a bug there? How can it be fixed?

Thanks in advance.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Andrey Kiselnikov 2019-8-6

Before using the interfaces you should create the system object that will control the board. Can you attach your script here?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Andrey Kiselnikov 2019-8-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/475008-spi-mode-and-bitrate-cannot-be-changed-in-arduino-due#answer_386430

Right now I have no Arduino Due, but I can check your script next week. If it will be actual, let me know please.

3 个评论
显示 1更早的评论隐藏 1更早的评论

Andrey Kiselnikov 2019-8-12

Hi, I remember what i promised!

>> a = arduino()
a = 
  arduino with properties:
                  Port: 'COM6'
                 Board: 'Due'
         AvailablePins: {'D2-D53', 'A0-A11'}
  AvailableDigitalPins: {'D2-D53', 'A0-A11'}
      AvailablePWMPins: {'D2-D13'}
   AvailableAnalogPins: {'A0-A11'}
    AvailableI2CBusIDs: [0, 1]
             Libraries: {'SPI'}
>> dev = spidev(a,'D10','Mode',3,'Bitrate',1000000)
Warning: Function spidev will be removed. Use device instead.Click here to turn off this warning. 
dev = 
  spidev with properties:
    ChipSelectPin: D10
             Pins: SPI-4(MOSI), SPI-1(MISO), SPI-3(SCK)
             Mode: 3               (0, 1, 2 or 3)
         BitOrder: msbfirst        ('msbfirst' or 'lsbfirst')
          BitRate: 1000000         (Hz)

And...... I'll create an "issue" in MW inner support service to research this bug and properly describe all limitations. If it was useful for you, mark the answer as accepted.

Massoud Tohidian 2019-8-12

Thanks so much. Please also note that Mode is not properly set to 3, and it is still in Mode 0. In Mode 3 data should be stable at falling edge, not rising.

I appreciate if you could follow it up with Mathworks and post here again any solution you find.

请先登录，再进行评论。

Answer 2

Massoud Tohidian 2019-8-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/475008-spi-mode-and-bitrate-cannot-be-changed-in-arduino-due#answer_386382

编辑：Massoud Tohidian 2019-8-6

Yes fore sure I have created the system object beforehand. Here is the complete code:

a = arduino()
dev = spidev(a,'D10','Mode',3,'Bitrate',1000000)
writeRead(dev,15);

And it returns this:

a = 
 
arduino with properties:
                    Port: 'COM3'
                   Board: 'Due'
           AvailablePins: {'D2-D53', 'A0-A11'}
               Libraries: {'I2C', 'SPI', 'Servo'}
               
dev = 
  spidev with properties:
    ChipSelectPin: D10
             Pins: SPI-4(MOSI), SPI-1(MISO), SPI-3(SCK)
             Mode: 3               (0, 1, 2 or 3)
         BitOrder: msbfirst        ('msbfirst' or 'lsbfirst')
          BitRate: 1000000     