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Maximum frequency for ADC

23 Views - Created 12 days ago

12 days ago

Posted by:
tfv3

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Hi,

what would be the maximum expected sampling frequency for ADC? Is this tutorial

https://www.abelectronics.co.uk/kb/article/1074/adc-reading-tutorial-on-the-expander-pi

using I2C or SPI?

Thanks,

tfv

11 days ago

Posted by:
andrew

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Location:
United Kingdom

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Hi

The maximum sampling frequency for the ADC on the Expander Pi is dependant on several factors, the main two being the programming language and the model of Raspberry Pi.

On a Raspberry Pi 3 B+ using python you can expect to get a sample rate of approximately 13500 samples per second.  Using C you can get a sample rate of 32000 samples per second.  The C language is more than twice as fast because it uses a compiled program that has less CPU overhead than interpreted languages like Python.

Other factors can have an impact on the sample rate such as CPU load from other processes and the SPI bus speed so your maximum sample rate may be lower.

We have ADC speed test scripts for Python, C, C++ and Node JS which you can use to compare the performance of the ADC on your Raspberry Pi.  All of the tests use our Expander Pi libraries which can be found on our Github repository at https://github.com/abelectronicsuk

AB Electronics UK Tech Support

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