Other Parts Discussed in Thread: ADS8691
We are testing out an ADS8699 ADC and I have two questions:
My understanding is that if one uses the default values for range, etc., one should be able to read out the ADC values at +/- 3*Vref by sending CS low, providing a clock signal, and transferring out the bytes via SPI:
byte firstByte = SPI.transfer (B00000000);
byte secondByte = SPI.transfer(B00000000);
byte thirdByte = SPI.transfer(B00000000);
byte fourthByte = SPI.transfer(B00000000);
and that no further setup is necessary (again, for the ADC default setup, range = -12.288 to 12.288).
In testing, I get an output from this ADC (for example, if I am reading a 5v source on the analog in):
02:10:11.146 -> first byte: 10101111
02:10:11.146 -> second byte: 110010
02:10:11.146 -> third byte: 11000000
02:10:11.146 -> fourth byte: 0
bits 14 to 31 should contain the output, is that at least the right idea?
2) I read the spec sheet, but I'm still uncertain about how to interpret the result using a bipolar range. I wish there were examples or more information. I did see this document:
http://www.ti.com/lit/an/sbaa042a/sbaa042a.pdf?ts=1590477524201 and I'm wondering if the ADS8699 uses the bipolar offset binary scheme or ???