5 Replies Latest reply on Feb 26, 2015 2:37 PM by KurtE

    Can't program SPI SCK higher than 4MHz Edison mini breakout board



      I am trying to connect a MCP4922 DAC to the Edison mini breakout board. I am using python mraa library and yocto image. There is a function under mraa.Spi class that will set up the SCK frequency as you want, but it seems that is not working since I am looking to set the SPI SCK to 20MHz as is needed by this DAC.


      import mraa as m


      dev = m.Spi(0)




      while True:

        txbuf = bytearray(2)

        txbuf[0] = 0b00000000

        txbuf[1] = 0b01110101



      Using a scope I am seeing that SCK is 6.2MHz. For some reason using this code I am not able to see any voltage at the DAC output so I am thinking it could be the SPI SCK speed.


      I will really appreciate your help. Thanks