Brontekst bekijken van MCP23017

 
{{Project
 |Name=MCP23017 
 |Picture=Mcp23017.jpg
 |Omschrijving= Guide: Connecting MCP23017 to ESP8266
 |Status=Completed
 |Contact=Sttc
}}


== Status ==
Status as of 2020/1/13:
*Completed
  

== Introduction ==
MCP23017 is a GPIO expander that runs on I2C.
This page forms wiring and communication guide for MCP23017 on ESP8266.

Used components:
* MCP23017 
MCP23017 I2C Interface 16bit I/O Extension Module Pin Board IIC to GIPO Converter 
https://www.aliexpress.com/item/32883688022.html?spm=a2g0s.9042311.0.0.5d3e4c4d6bMkco

* ESP8266:  
LoLin NodeMCU V3  4MB flash ESP8266 12E
More info on ESP8266:
https://randomnerdtutorials.com/esp8266-pinout-reference-gpios/

== Wiring ==

Setting up ESP8266 for I2C pins is not necessary in this code. SCL and SDA pins as below:
 
Connecting pins between MCP23017 and ESP8266
{| class="wikitable"
|-
! MCP23017 <-- !! --> ESP8266
|-
| GND || GND
|-
| VCC || 3V
|-
| SCL || D1 (GPIO5)
|-
| SDA || D2 (GPIO4)
|}

== Code ==

Required libraries:
*Wire
*Adafruit_MCP23017

 // MCP23017 Example: Slow key press reaction.
 //
 // Toggle LEDs and detect keypress.
 //
 // Example code showing slow reaction of 'button' 
 // LED to keypress. Leading into why interrupts
 // are useful (See next example).
 //
 // Copyright : John Main
 // Free for non commercial use.
 
 #include <Wire.h>
 #include <Adafruit_MCP23017.h>
 
 #define MCP_LED1 7
 #define MCP_INPUTPIN 8
 #define MCP_LEDTOG1 11 
 
 Adafruit_MCP23017 mcp;
   
 void setup() {  
   mcp.begin();      // Default device address 0
 
   mcp.pinMode(MCP_LEDTOG1, OUTPUT);  // LED for blinking
   
   mcp.pinMode(MCP_LED1, OUTPUT);     // LED output for button
   
   mcp.digitalWrite(MCP_LED1, HIGH);  // default > LED turn on
 
   mcp.pinMode(MCP_INPUTPIN,INPUT);   // Button i/p to GND
   mcp.pullUp(MCP_INPUTPIN,HIGH);     // Puled high to ~100k
 }
  
 void loop() {
 
   // blinking led
   delay(300);
   mcp.digitalWrite(MCP_LEDTOG1, HIGH); 
   delay(300);
   mcp.digitalWrite(MCP_LEDTOG1, LOW); 
   
   
   
   // Transfer input pin state to LED1
   if (mcp.digitalRead(MCP_INPUTPIN)) {
      mcp.digitalWrite(MCP_LED1,HIGH);
   } else {
      mcp.digitalWrite(MCP_LED1,LOW);
   }
   
 }

== MCP21017 GPIO ==
Number in IDE = 
<br>
mcp.pinMode(''Number in IDE'', OUTPUT);
 
 
{| class="wikitable"
|-
! MCP21017 !! Number in IDE
|-
| PA0 || 0
|-
| PA1 || 1
|-
| PA2 || 2
|-
| PA3 || 3
|-
| PA4 || 4
|-
| PA5 || 5
|-
| PA6 || 6
|-
| PA7 || 7
|-
| PB0 || 8
|-
| PB1 || 9
|-
| PB2 || 10
|-
| PB3 || 11
|-
| PB4 || 12
|-
| PB5 || 13
|-
| PB6 || 14
|-
| PB7 || 15
|}
 
== Remarks == 
*Pins of VCC,GND,SCL,SDA,RT,ITA,ITB line do not fit to the board together with GPIO pins (PA7, PA6...) > (Do not solder VCC... line pins)
<br>
*ESP8266 configuration on Arduino IDE:
<br>

[[File:ESP conf.png|100px|left|thumb|esp8266]]
<br>