Introduction - If you have any usage issues, please Google them yourself
/// The basic specs of the ADS7870 are:
/// - Fast SPI interface (up to 20MHz)
/// - 12-bit results
/// - 8 single-ended or 4 differential input channels
/// - Programmable gain stage (1,2,4,5,8,10,16,20x gains)
/// - Software or hardware triggered conversion
/// - 4-bit auxiliary digital I/O lines (controlled via serial interface)
/// - Up to 50KHz conversion rate
/// - External reference or internal 2.5V, 2.048V, 1.15V reference
/// - NOTE: use pin-compatible ADS7871 for 14-bit results