AD5933 - Part4 （Arduino Library Example)

AD5933 - Part4 （Arduino Library Example)

arduino-ad5933/examples/ad5933-test/ad5933-test.ino

2016may04

	/*
	ad5933-test
	Reads impedance values from the AD5933 over I2C and prints them serially.
	*/
	#include <Wire.h>
	#include "AD5933.h"
	#define START_FREQ (80000)
	#define FREQ_INCR (1000)
	#define NUM_INCR (40)
	#define REF_RESIST (10000)
	double gain[NUM_INCR+1];
	int phase[NUM_INCR+1];
	void setup(void)
	{
	// Begin I2C
	Wire.begin();
	// Begin serial at 9600 baud for output
	Serial.begin(9600);
	Serial.println("AD5933 Test Started!");
	// Perform initial configuration. Fail if any one of these fail.
	if (!(AD5933::reset() &&
	AD5933::setInternalClock(true) &&
	AD5933::setStartFrequency(START_FREQ) &&
	AD5933::setIncrementFrequency(FREQ_INCR) &&
	AD5933::setNumberIncrements(NUM_INCR) &&
	AD5933::setPGAGain(PGA_GAIN_X1)))
	{
	Serial.println("FAILED in initialization!");
	while (true) ;
	}
	// Perform calibration sweep
	if (AD5933::calibrate(gain, phase, REF_RESIST, NUM_INCR+1))
	Serial.println("Calibrated!");
	else
	Serial.println("Calibration failed...");
	}
	void loop(void)
	{
	// Easy to use method for frequency sweep
	frequencySweepEasy();
	// Delay
	delay(5000);
	// Complex but more robust method for frequency sweep
	frequencySweepRaw();
	// Delay
	delay(5000);
	}
	// Easy way to do a frequency sweep. Does an entire frequency sweep at once and
	// stores the data into arrays for processing afterwards. This is easy-to-use,
	// but doesn't allow you to process data in real time.
	void frequencySweepEasy() {
	// Create arrays to hold the data
	int real[NUM_INCR+1], imag[NUM_INCR+1];
	// Perform the frequency sweep
	if (AD5933::frequencySweep(real, imag, NUM_INCR+1)) {
	// Print the frequency data
	int cfreq = START_FREQ/1000;
	for (int i = 0; i < NUM_INCR+1; i++, cfreq += FREQ_INCR/1000) {
	// Print raw frequency data
	Serial.print(cfreq);
	Serial.print(": R=");
	Serial.print(real[i]);
	Serial.print("/I=");
	Serial.print(imag[i]);
	// Compute impedance
	double magnitude = sqrt(pow(real[i], 2) + pow(imag[i], 2));
	double impedance = 1/(magnitude*gain[i]);
	Serial.print(" |Z|=");
	Serial.println(impedance);
	}
	Serial.println("Frequency sweep complete!");
	} else {
	Serial.println("Frequency sweep failed...");
	}
	}
	// Removes the frequencySweep abstraction from above. This saves memory and
	// allows for data to be processed in real time. However, it's more complex.
	void frequencySweepRaw() {
	// Create variables to hold the impedance data and track frequency
	int real, imag, i = 0, cfreq = START_FREQ/1000;
	// Initialize the frequency sweep
	if (!(AD5933::setPowerMode(POWER_STANDBY) && // place in standby
	AD5933::setControlMode(CTRL_INIT_START_FREQ) && // init start freq
	AD5933::setControlMode(CTRL_START_FREQ_SWEEP))) // begin frequency sweep
	{
	Serial.println("Could not initialize frequency sweep...");
	}
	// Perform the actual sweep
	while ((AD5933::readStatusRegister() & STATUS_SWEEP_DONE) != STATUS_SWEEP_DONE) {
	// Get the frequency data for this frequency point
	if (!AD5933::getComplexData(&real, &imag)) {
	Serial.println("Could not get raw frequency data...");
	}
	// Print out the frequency data
	Serial.print(cfreq);
	Serial.print(": R=");
	Serial.print(real);
	Serial.print("/I=");
	Serial.print(imag);
	// Compute impedance
	double magnitude = sqrt(pow(real, 2) + pow(imag, 2));
	double impedance = 1/(magnitude*gain[i]);
	Serial.print(" |Z|=");
	Serial.println(impedance);
	// Increment the frequency
	i++;
	cfreq += FREQ_INCR/1000;
	AD5933::setControlMode(CTRL_INCREMENT_FREQ);
	}
	Serial.println("Frequency sweep complete!");
	// Set AD5933 power mode to standby when finished
	if (!AD5933::setPowerMode(POWER_STANDBY))
	Serial.println("Could not set to standby...");
	}