I2CIO16-DB25

16-Bit Digital I/O Card with DB25 Connector

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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
  • Fuse protected power output on DB-25 with jumper bypass
• Large prototyping area
  • Connections at edges to DB-25 and GPIO lines
• EEPROM for board ID and application specific information
  • Write Enable jumper protects against accidental writes
• Open Data Acquisition System (ODAS) form factor (width is 95 mm)
• Host connectors
  • Daisy-chain I2C connector
  • Address select jumper
  • Expandable I2C via I2C-RPT - I2C Repeater
  • Interrupt out/Card Present
  • Power connector (not required for minimal loads)
    • Reversible pinout for safety
  • I2C Termination jumpers for end of I2C chain
• Power can be 3.3V or 5V
• 95mm wide Open Data Acquisition System format
• 6-32 Mounting holes

Connectors

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H1 - Address Select

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

1. A0
2. A1
3. A2

H2 - 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

H4 I2C Termination

• Two of two position headers
• Install headers in each position to terminate I2C line
• There should only be one I2C termination and it should be at the end of the I2C line

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

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

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

EEPROM

• 24LC024 EEPROM
  • 2kbit
  • I2C Serial EEPROM
  • Wide Voltage range (1.8V to 5.5V)
  • 400 KHz operating range
• 10 mS write cycle time
• EEPROM has a board ID
  • ODAS EEPROM Code

Factory Acceptance Tests

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Setup

• Runs ODAS Card Test Software on Arduino Nano NANO-BKOUT with I2C-RPT card
• USB running puTTY
  • 9600 baud

Program Personality EEPROM

• Menu driven
• Auto-detects card
• If test has been run before

Checking EEPROM for board type...Detected PROTO16-I2C board
R=Read EEPROM, W=Write EEPROM, T=Test DIGIOs, L=Loop Test, B=Bounce LEDs

• Presents card type list for un-programmed EEPROMs

Checking EEPROM for board type...Company Mismatch
Select the board type
1 - DIGIO16-I2C board
2 - DIGIO-128 board
3 - OptoIn8-I2C board
4 - OptoOut8-I2C board
5 - DIGIO32-I2C board
6 - PROTO16-I2C board
7 - ODAS-PSOC5 board
8 - TBD board
9 - TBD board
Select board > 

• Select board

Select board > 6
Writing EEPROM
Initializing eep buffer
len of buffer=96
reading block
Family=ODAS
Company=land.boards.com
Product=PROTO16-I2C

Run I2C Loopback Tests

• Test 'T'

Loopback Test PASS = 1, FAIL = 0

Run Bouncing LEDs

• Select B

Bouncing LEDs - any key to stop

• Use LED card

PROTO16-I2C Assembly Sheet

• I2CIO16-DB2 Rev 1 Assembly Sheet