How to use different device address for MCP23017 so I can use multiple chips?

Question

I want to use more than 3 MCP23017-E/SP DIP28 chips so I can use many digital pins. I use Adafruit-MCP23017-Arduino-Library. I tried this solution but only device address with 0x00 is working.

The question is what device address should I use for additional chip? enter image description here

#include "Adafruit_MCP23017.h" 
Adafruit_MCP23017 mcp1; 
#define addr1 0 // tested 1,2,3,4,5, 0x01, 0x02, 0x20, 0x21 but only 0 and 0x00 is working.
void setup() 
 {
 mcp1.begin(addr1); 
 mcp1.pinMode(0, INPUT); //pin 21 on chip
 Serial.begin(9600); 
 } 
 void loop()
 { 
 if(mcp1.digitalRead(0)== HIGH )
 Serial.println("HIGH"); 
 }

Answer 1

I share my solution with 7 MCP23017 chip , 7x14 pins=98 pins using adafruit library.

Connections:

addr 0 = A2 low , A1 low , A0 low 000
addr 1 = A2 low , A1 low , A0 high 001
addr 2 = A2 low , A1 high , A0 low 010
addr 3 = A2 low , A1 high , A0 high 011
addr 4 = A2 high , A1 low , A0 low 100
addr 5 = A2 high , A1 low , A0 high 101
addr 6 = A2 high , A1 high , A0 low 110
addr 7 = A2 high, A1 high, A0 high 111
Connect pin #12 of the expander to Analog 5 (i2c clock)
Connect pin #13 of the expander to Analog 4 (i2c data)
Connect pins #15, 16 and 17 of the expander to ground (address selection)
Connect pin #9 of the expander to 5V (power) // operation voltage is 1.8 to 5.5
Connect pin #10 of the expander to ground (common ground)
Connect pin #18 through a ~10kohm resistor to 5V (reset pin, active low)
Input #0 is on pin 21 so connect a button or switch from there to ground

Code:

#include <Adafruit_MCP23017.h>
Adafruit_MCP23017 mcp1; // chip 1
Adafruit_MCP23017 mcp2; // chip 2
#define addr1 7 // 7 = A2 high, A1 high, A0 high
#define addr2 0 // 0 = A2 high, A1 high, A0 high
void setup() 
 {
 Serial.begin(9600); 
 mcp1.begin(addr1);
 mcp2.begin(addr2);
 mcp1.pinMode(0, INPUT); //pin 21 on chip
 mcp2.pinMode(0, INPUT); //pin 21 on chip
 } 
 void loop()
 { 
 if(mcp1.digitalRead(0)== HIGH )
 Serial.println("HIGH"); 
 delay(1000);
 if(mcp2.digitalRead(0)== HIGH )
 Serial.println("HIGH 2"); 
 delay(1000);
 }