Hi,
I am working on a project that requires the use of audio signals as inputs, and I had some concerns regarding the sampling rates of the Analog inputs
I'm confused about what the Galileo's actual capabilities are in terms of the sampling rates for the ADC used with the analog input pins (A0 through A5). I understand that the Galileo is capable of handling up to 12 bits per sample, and is set to 10 bits per sample by default, as is mentioned in the FAQ.
However, my concern relates to the question in the FAQ regarding the maximum rate at which the GPIO output pins can be updated, and how this might impact sampling rates.
The answer given says:
The GPIO output pins on Intel® Galileo are provided by an I2C Port Expander that is running at standard mode (100 kHz). Each I2C request to update a GPIO requires approximately 2ms. In addition to software overhead, this restricts the frequency achievable on the GPIO outputs to approximately 230 Hz.
So, what I am having trouble understanding is:
- Does the GPIO only refer to the 14 Digital I/O pins, or is it also a blanket term that incorporates the 6 Analog pins as well?
- Does this 500 Hz, or 2 millisecond, restriction (230 Hz when factoring in the software overhead) only apply specifically to Data OUTPUT (as in, INPUT data is not affected by this limitation)?
- If INPUTS to the 6 Analog pins are not ultimately hindered by this 230 Hz limitation, what is the actual maximum sampling rate that can be achieved for an input signal?
Any clarification would be appreciated.
