PROTO16-I2C

16-Bit Digital I/O Card with Prototyping area

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

Prototyping Area

• Large prototyping area
• Ideal for through-hole ICs
• Extra I/O Rows on both sides
  • One side connects to DB-25 connector
  • Other side connects to MCP23017 pins
• Prototyping area in the center of the card with power/ground bus up the middle two pins
  • Easy connection to IC Power/Grounds
• Silkscreen on both sides of the card

• The above is the top two rows of the prototyping area
• The pins on the far left are the pin number of the DB-25 connector (ex: Pin 24 is the top left, and pin 11 is in the next row).
• The next 3 pins are bussed across to each other (the same row)
• The next column has GND in all column positions
• The next column has VCC in all column positions
• The next 3 pins are bussed across to each other (the same row)
• The far right pin has the DIGIO part connections (blank for the first row and Digital I/O pin 8 in the next point).

Connectors

H1 - Power

• Connector is 1x5 of 0.1" header
• Connector is reversible
• Connector is optional since power can also be brought in via the I2C connector

1. GND
2. PWR
3. GND
4. PWR
5. GND

H2 - Interrupt/Card Present Flag

1. GND
2. INT0*
3. CARD_PRESENT* (Low if card is present, should be pulled up by Host card)

H3 - Address Select

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

1. A0
2. A1
3. A2

H4 - 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. SCL
2. SDA
3. VCC
4. GND

H5 - EEPROM Write Enable

• Install to allow writes to EEPROM
• Remove to prohibit writes to EEPROM

H6 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

Proto16-I2C-P1010614-720px.jpg

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-Card-WithPogos-720px-P569.jpg

Issues with Rev X1 board

Add A0 jumper for EEPROM and MCP23017 Verified works in Rev X2 (Kickstarter)

Assembly Sheet

Proto16-I2C Assembly Sheet

PROTO16-I2C Assembly Sheet

PROTO16-I2C Assembly Sheet Rev X1