/***
? VK4PLN's AGC Code. Adafruit TPA2016
Add call to setupTPA2016(); to main code setup() in ubitx_20 after initOscillators();
/
?
#include <Wire.h>
#include "Adafruit_TPA2016.h"
?
Adafruit_TPA2016 audioamp = Adafruit_TPA2016();
?
void setupTPA2016() {
??
? audioamp.begin();
? // See Datasheet page 22 for value -> dBV conversion table
//? Serial.println("Right off, Left On,");
? audioamp.enableChannel(false, true);
?
? // Noise Gate Threshold: Below this value, the AGC holds the gain to prevent breathing effects.
? //Select the threshold of the noise gate (1,4,10,20mV) (0-3)
//? Serial.println("Noise Gate Threshold,");
? //Disable NoiseGate, we want to hear everything, even weak signals....
? audioamp.enableNoiseGate(false);
? audioamp.setNoiseGateThreshold(0);
??
? // Fixed Gain: The normal gain of the device when the AGC is inactive.
? // The fixed gain is also the initial gain when the device comes out of shutdown mode or when the AGC is disabled.
? // value 6 seems to work ok... based on datasheet. Where gain is from -28 (dB) to 30 (dB)
// Serial.println("Setting Fixed Gain");
? audioamp.setGain(-12); //-27 is ok? -12 is too high local stations arnt clipped...
?
? ? // Compression Ratio: The relation between input and output voltage.
? // AGC can be TPA2016_AGC_OFF (no AGC) or
? //? TPA2016_AGC_2 (1:2 compression)
? //? TPA2016_AGC_4 (1:4 compression) * Datasheet - Voice
? //? TPA2016_AGC_8 (1:8 compression)
//? Serial.println("Setting AGC Compression");
? audioamp.setAGCCompression(TPA2016_AGC_8);
?
? // Limiter Level: The value that sets the maximum allowed output amplitude.
//? Serial.println("Setting Limit Level");
? audioamp.setLimitLevelOn();
? // or turn off with?
? //audioamp.setLimitLevelOff();
? audioamp.setLimitLevel(30);? // range from 0 (-6.5dBv) to 31 (9dBV) (8.5dBv(30) as per datasheet)
?
? //Maximum Gain: The gain at the lower end of the compression region
//? Serial.println("Setting AGC Max Gain (18-30db - (0-12)");
? audioamp.setAGCMaxGain(12);
?
? /*
? ?*? ?For voice systems the attack time should be in the 2-ms region, with a hang time of about 0.3 sec,
? ?*? ?followed by a gradual recovery time of up to 1 sec.?
? ?*? ?http://www.qsl.net/va3iul/Files/Automatic_Gain_Control.pdf
? ?*
? ?*/
??
? // See Datasheet page 23 for value -> ms conversion table
//? Serial.println("Setting AGC Attack (0.1-6.7ms - (0-63))");
? audioamp.setAttackControl(3);
??
? // See Datasheet page 24 for value -> ms conversion table
//? Serial.println("Setting AGC Hold (0.0137-0.8631ms - (1-63))");
? audioamp.setHoldControl(0);
??
? // See Datasheet page 24 for value -> ms conversion table
//? Serial.println("Setting AGC Release (0.0137-0.8631ms - (0-63))");
? audioamp.setReleaseControl(4);
}
Nick VK4PP