I2CIO16-DB25

Features

• 16-bit Digital I/O card
  • MCP23017 16-bit I2C I/O Expander
  • Strong library support for all major microprocessors for MCP23017
• I2C Interface - Two Wire Interface
  • Can run at 400 KHz or faster
• I/O Connector is inexpensive/standard DB-25
• Host connectors
  • Daisy-chain I2C connector
  • Address select jumper
  • I2C base address = 0x20
  • Jumpers allow card to be put at any I2C address in range 0x20-0x27
  • Expandable I2C via I2C-RPT - I2C Repeater
  • I2C Termination jumpers for end of I2C chain
• Power can be 3.3V or 5V
• 6-32 Mounting holes

Connectors

J1 - DB-25 I/O Connector

• Pins 1, 2, 14 are connected to Ground
• Pins 12, 13, 25 are connected to Power
• Pins 3-11 and 15-24 are connected to the Prototype area and are labeled on the PCB

J2 - I2C Termination

• Two of two position headers
• Install headers in each position to terminate I2C line
• There should only be one set of I2C termination jumpers and termination should be at the end of the I2C line
• Side by side not vertically (opposite of Address jumpers orientation)

J3 - I2C

• Connector is 2x5 of 0.1" header
• Intended to be used for I2C daisy-chain of 4-pin cabling
• Power can be attached to the connector or power can be provided to the card via the J1 power connector
• May still want to connect ground

1. INT
2. SCL
3. SDA
4. VCC
5. GND

J4 - Address Select

• Sets the I2C offset address of the card
• Three bit address A1, A2

1. A0
2. A1
3. A2

• Juper orientation

Rear Side Marking

MCP23017 Drivers

There are quite a I2C drivers for every major microcontroller (Arduino, Raspberry Pi, BeagleBone, etc).

Arduino Drivers

• Land Boards Arduino Driver Code/Example Software for the PROTO16-I2C Card
• Adafruit MCP23017 Arduino Driver

Raspberry Pi Drivers

• Raspberry Pi WiringPi Driver

Raspberry Pi Pico

MMBASIC

• I2CIO16-DB25.bas code to bounce an LED
  • Runs on PiPicoMite01 or PiPicoMite02 card

BeagleBone Black Drivers

• BeagleBone Black Example

ESP32 MicroPython Drivers

• MicroPython MCP23017 driver
• MicroPython Example code

PyBoard MicroPython Drivers

• MicroPython MCP23017 driver
• MicroPython Example

Linux Drivers

• Linux Driver source code

Mechanicals

Factory Acceptance Tests

• Unit Under Test (UUT)
• Runs on PiPicoMite01 or PiPicoMite02 card
• Run I2CIO8-DB25.bas code
• I2C cable to UUT
• LED-32 card
• DB25RIBBON plugged into UUT
• Cable between LED-32 and DB25RIBBON

• Code bounces LED

PROTO16-I2C Assembly Sheet

• I2CIO16-DB25 Rev 1 Assembly Sheet