MCP23017 - i2c

For other supported Arduino products from Adafruit: Shields, accessories, etc.

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
rahatmaini
 
Posts: 176
Joined: Wed Aug 29, 2012 5:15 pm

MCP23017 - i2c

Post by rahatmaini »

I understand that Adafruit has a library for this, however, I do not know how to assemble this and wire it correctly. Is there anyplace that has detailed instructions for utilization of this chip, I do not know much about arduino as I am very new to this.

tldr
 
Posts: 466
Joined: Thu Aug 30, 2012 1:34 am

Re: MCP23017 - i2c

Post by tldr »

start with the datasheet. it's linked from the product page.

pin nine is power and pin ten is ground.

pins 15,16 and 17 are address pins. just them to ground.. if you are going to put multiple mcp23017's on the same bus you can connect some of these pins to 5v to form up to seven additional addresses.

pins 12 and 13 are your i2c bus. 12 is the clock line and 13 is data. you might want pullups on these lines, though the arduino is supposed to take care of that.

pins 21-28 will be referred to as pins 0-7 in your code. pins 1-8 on the chip will be pins 8-15 in your code.

aaaargh. what am i doing? all of this is explained in the example code in the library.

@#?!&

User avatar
rahatmaini
 
Posts: 176
Joined: Wed Aug 29, 2012 5:15 pm

Re: MCP23017 - i2c

Post by rahatmaini »

Thanks so much! Very helpful indeed, so i2c is just a fancy word for A4 and A5 on the arduino, huh? Tricky.

Locked
Please be positive and constructive with your questions and comments.

Return to “Other Arduino products from Adafruit”