mcc hat options for precision measurement of analog sensor

[_jm]

Hello.

I have an MCC128 hat, and it works well to sample data @ 1kHz from an analog sensor connected to the data acquisition board via a differential analog input. A continuous scan over many hours (5+ hours) works flawlessly for my application.

To characterize the sensor noise properties, I typically acquire data over several hours and apply statistical techniques. As I am interested in the noise properties, I also configure the MCC128 to +/-1V to maximize the available resolution.

I suspect the reason why my calculations do not match the sensor's datasheet for certain timescales is due to the 16-bit A/D converter.

Looking for options to test out this hypothesis. There are several other MCC hats for the rpi with 24-bit A/D converters, but those seem tailored to specific sensors and/or do not support the 1kHz sample rates of interest.

Is there a drop-in, pin-compatible 24-bit A/D converter that can be installed in the MCC 128? Are there firmware options to change the voltage range to something tighter than +/-1V or is that a limitation of hardware on the hat?

Any other thoughts?

 

[JRys]

The MCC 128 specifications, including accuracy and noise, are listed in the following document: https://mccdaq.github.io/daqhats/_static/esmcc128.pdf. 

24-bit sigma-delta A/D converters work differently than the MCC 128 successive approximation converter. It would be a complete redesign to make the change.

The input voltage ranges are provided by a set of resistors that, when selected, change the amplification factor. We do not offer support if someone wants to change the resistor values. I recommend providing your amplification stage separate from the MCC 128 so that your sensor signal is larger and compatible with the one voltage range.

 

[_jm]

Thanks for the prompt and thorough response