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Is the MCP3202 clock frequency set right?

1625 Views - Created 18/05/2016

18/05/2016

Posted by:
jpsa

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I could easily be confused here (I'm not an expert at reading datasheets, nor at using the spidev package!), but both the Python 2 and 3 libraries include the line

spiADC.max_speed_hz = (4000000)

(4 MHz). However the datasheet for the MCP3202 gives maximum clock speeds of 0.9 MHz at V_DD=2.7V, and 1.8 MHz at V_DD=5.0V.

Certainly I'm getting much better results from the ADC side of the ADC DAC Pi if I reduce this max speed setting.

18/05/2016

Posted by:
andrew

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Location:
United Kingdom

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Thank you for spotting the mistake with the python libraries.  You are correct the ADC clock speed should have been 0.9MHz.

I have updated the python 2 and python 3 libraries with the correct clock rate.

AB Electronics UK Tech Support

19/05/2016

Posted by:
jpsa

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Thank you!

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