14m2/mcp23017 interface circuit diagram

[B-Joe]

Hi all. Im looking for a circuit diagram to interface my io expander with my picaxe 14m2. I intend to later use it to connect my lcd and 4x3 keypad. I got the code some time ago and have searching the web for the diagram but no luck. Please help.

 

[westaust55]

Using iPhone currently so not in a position to draw a schematic.

At the basic level, all you need is between your 14M2 and the MCP23017 is:
I2c clock pins connected
I2c data pins connected

If you are going to use interrupts, for example to detect when a keypad press has occurred, then also connect from the MCP23017 interrupt pin to a portC pin on your 14M2.
MCP23017 pin 20 (INTA) if you want to monitor portA
MCP23017 pin 19 (INTB) if you want to monitor portB

 

[lbenson]

There's a lot more on this breadboard (as there no doubt will be on yours), but here a MCP23017 used with a 20M2, displayed using the Pebble program written by westaust55.



Note the address lines and the pull-up on *RESET.

 

[B-Joe]

Thankyou so much, Guys. I will try this and let you know how it prigresses.