edgar-bonet

/*
 * homodyne.ino: Homodyne detection of a 1 kHz signal.
 *
 * This program continuously samples analog input 0 and uses an homodyne
 * detection scheme to identify a signal at 1 kHz (+/- 24 Hz @ -3dB).
 *
 * The analog-to-digital converter is set to "free running mode" and
 * takes one sample every 104 us. The samples are multiplied by two
 * generated signals at 1 kHz (the "local oscillator"), in quadrature to
 * one another. The products are then low-pass filtered with a time

ridencww

/*
 * Simple printf for writing to an Arduino serial port.  Allows specifying Serial..Serial3.
 * 
 * const HardwareSerial&, the serial port to use (Serial..Serial3)
 * const char* fmt, the formatting string followed by the data to be formatted
 * 
 * int d = 65;
 * float f = 123.4567;
 * char* str = "Hello";
 * serial_printf(Serial, "<fmt>", d);