MCP23017 控制 MAX9814

/**
* This sketch tests the MAX9814 library.
* It just toggles the gain and release/attack ratio of a single MAX9814
* if you attach two as instructed and breadboard them next to each other,
* you should see a difference in their signals.
*
* The library lets you control the Release/Attack ratio and gain of the MAX9814:
* http://www.maximintegrated.com/en/products/analog/audio/MAX9814.html
*
* Note that the data sheet gives the attack/release ratio; while the library
* writes this as release/attack ratio, this difference is solely for readability;
* it is functionally identical,
*
* This library requires the ICUsingMCP23017 library, MCP23017 library, Wire.h, Arduino.h
*
* In this example, an ESP8266 was connected to the MAX9814 via an MCP23017,
* but you can do it with an Arduino and/or omit the MCP23017 GPIO expander
* connections are as follows:
*
*    ESP8266    ->    MCP23017
*    GPIO 4(SDA)->    Pin 13
*    GPIO 5(SCL)->    Pin 12
*
*    MCP23017
*    Pin 9 -> 3.3V, Pin 10 -> GND,
*    Pin 15, 16, 17 (A0, A1, A2) -> GND, Pin 18 (!RESET) -> Vcc via 10K resistor
*
*    MCP23017        ->    first MAX9814 breakout (ch0)
*    Pin 21(GPA0)    ->    A/R Pin
*    Pin 22(GPA1)    ->    GAIN Pin
*    
*    MCP23017        ->    second MAX9814 breakout (ch1)
*    Pin 23(GPA2)    ->    A/R Pin
*    Pin 24(GPA3)    ->    GAIN Pin
*
*    MAX9814 breakout (both channels)
*    Vcc             ->     Vcc
*    GND             ->     GND
*    OUT             ->     Oscilloscope
*
*
*    Hook up one channel of your oscilloscope
*    to the OUT on the MAX9814
*    to see how it changes
*/

#include <Arduino.h>
#include <Wire.h>
#include
#include
#include

// MAX9814 control pins
// ...you could add more audio channels
// by duplicating the following
// and changing accordingly
#define CH_0_RA_PIN 0 //GPA0
#define CH_0_GAIN_PIN 1 //GPA1
#define CH_1_RA_PIN 2 //GPA2
#define CH_1_GAIN_PIN 3 //GPA3

//how long should we remain in a specific mode before changing?
#define HOLD_TIME 1597

//define MAX9814 audio channels
//constructor sets default gain to 40dB
//and default release/attack to 500:1
Alislahish_MAX9814 ch0(CH_0_GAIN_PIN, CH_0_RA_PIN);
Alislahish_MAX9814 ch1(CH_1_GAIN_PIN, CH_1_RA_PIN);
Adafruit_MCP23017 mcp;
long lastMillis = 0L;
uint8_t ra = 0;
uint8_t gain = 0;
uint8_t mcpAddr = 0;
uint8_t led=LOW;

void setup()
{
   Serial.begin(115200);
   Serial.setDebugOutput(true);
   mcp.begin(mcpAddr);
   //make the MAX9814s use the same MCP23017
   ch0.setMCP23017(true, &amp;mcp, mcpAddr);
   ch1.setMCP23017(true, &amp;mcp, mcpAddr);
   //set led
   pinMode(BUILTIN_LED, OUTPUT);
   digitalWrite(BUILTIN_LED, led);
}

void loop()
{
   //change settings of audio ch0 if we've waited long enough
   if (millis() >= (lastMillis + HOLD_TIME))
   {
       lastMillis=millis();
       ra++;
       ra %= 3;
       if (ra == 0) {
           gain++;
           gain %= 3;
       }
       
       ch0.setGain(static_cast(gain));
       ch0.setRA(static_cast(ra));

       //reveal settings
       Serial.print("Gain: ");
       Serial.println(ch0.printGain());
       Serial.print("Release/Attack: ");
       Serial.println(ch0.printRA());
       
       //indicator led
       if(led==HIGH){
           led=LOW;
       } else {
           led=HIGH;
       }
       digitalWrite(BUILTIN_LED, led);
   }
}