DIGIO-128

Features

• 128 bits of General Purpose Digital I/O (GPIO)
  • Card uses I2C addresses 0x20-0x27 for I/O and 0x50 for Configuration EEPROM
• (8) of MCP23017 - 16 bit GPIO
  • I2C (Two Wire) host interface
  • 100/400 KHZ operation
  • 25mA sink/source capability per I/O
    • Limited by current in/out of the IC
• 24LC024 Configuration/Personality EEPROM
• Jumper selectable I2C terminators
• Single 4-pin host interface connector (Ground, Power, Clock, Data)
• (8) I/O Connectors
  • 20 pin, 0.1" Pitch
  • 16 digital I/O
  • 2 Power
  • 2 Ground
  • Interrupt connectors
• Power Connector
  • 3.3V or 5V operation
• 24LC024 I2C Personality EEPROM
• Compatible with Arduino, Raspberry Pi, BeagleBone Black
• 95x95mm form factor
• (4) 6-32 mounting holes - one on each corner

I2C Addresses

• MCP23017 parts 0x20 - 0x27
• EEPROM 24LC024 = 0x50

Connectors

P1-P4, P6-P9 - Digital I/O Connectors

• 16 bits per connector
• (2) Power
• (2) Ground

P5, P10 - Interrupt Outputs

• Interrupt lines out of the 8 MCP23017 ICs
• Can be used for detecting input changes or levels
• Interrupt outputs INTA from MCP23017
• Can be ignored if not needed
  • If the inputs are polled, the pins can be ignored

P5 pinout

• P5-1 = INT1
• P5-2 = INT2
• P5-3 = INT0
• P5-4 = INT3

P10 pinout

• P10-1 = INT5
• P10-2 = INT6
• P10-3 = INT4
• P10-4 = INT7

J1 - External Power

• Can be ignored if the card is powered through I2C connector

J2, J3 - I2C Connectors

• Daisy chained connections
• 2nd connector can be ignored
• Card can be powered through this connector(s)
• MCP23017 parts use I2C slave addresses 0x20-0x27
• EEPROM 24LC024 parts use I2C slave address 0x50
• Can't use more than one DIGIO-128 per I2C bus without separating busses with an I2C multiplexer
  • I2C-RPT - Land Boards 4-Channel I2C Multiplexer/Repeater
  • I2C-RPT-08 - Land Boards 8-channel I2C Multiplexer/Repeater

J4 - I2C Terminators and EEPROM Write Enable

• SDA, SCL I2C Terminators
  • Install jumper to use terminators
• WE - EEPROM Write Enable
  • Install To enable writing config EEPROM

Schematics

• Rev X3 schematic
• Rev X4 schematic

Configuration/Personality EEPROM

• 24LC024 Configuration/Personality EEPROM
• Read of EEPROM by ODAS Test Station

R=Read EEPROM, W=Write EEPROM, X=Exit Menu
Reading EEPROM
Family  = ODAS
Company = land-boards.com
Product = DIGIO-128
eepromAccessMenu() - Finished reading EEPROM

Testing

• DIGIO-128 Unit Under Test (UUT)
• UUT is tested using Arduino Based Test Station
• (4) 16:16 cables loop adjacent ports
  • Port 1 cabled to Port 2, Port 3 to Port 4, etc
• I2C cable from Arduino Based Test Station to UUT
  • 4 pin Dupont 1:1 cable
  • Plugged into Port 0 on STM32 Black Pill card on BLACK-PILL-HUB in Test Station
  • Plugged into I2C connector on UUT
• puTTY running on PC
  • USB-C cable to USB connector on STM32 Black Pill card on BLACK-PILL-HUB in Test Station
  • 9600 baud

Programming the Configuration EEPROM

• Type ENTER to display top level menu
• Type E to access EEPROM
• Type W to write EEPROM
• Menu will be:

R=Read EEPROM, W=Write EEPROM, X=Exit Menu
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 - ODAS-RELAY16 board
A - DIGIO-128/64 board
9 - TBD board
X - Boards without EEPROMs
Select board > 2

• Select 2
  • DIGIO-128 card

Writing EEPROM
Initializing eep buffer
len of buffer=96
reading block
Family=ODAS
Company=land-boards.com
Product=DIGIO-128

Test Code GitHub Repository

• ODAS Tester Github Repo

Software Examples/Drivers

• DIGIO-128 Arduino example code
• DIGIO-128 Arduino Driver
• DIGIO-128 - 64-bit version Arduino Driver
• DIGIO-128 Micropython Driver (ESP-32)
• Raspberry Pi Example Code - Requires some knowledge of the MCP23017 (datasheet)

Assembly Sheet

• DIGIO-128 Rev X4 Assembly Sheet
• DIGIO-128 Rev X3 Assembly Sheet