DIGIO32-I2C

Features

• 32-bit Digital I/O
  • Two MCP23017 16-bit I2C I/O Expanders
• 24LC024 ODAS Personality EEPROM
  • pid = 6
  • Write Enable jumper protects EEPROM against accidental damage
• I/O Connector is inexpensive/standard DB-37 Female
• I2C Interface
  • Daisy-chain I2C connector
  • I2C Termination jumpers for end of I2C chain
  • I2C Address select jumper (2 addresses - can support up to 4 cards)
• Power Options
  • Supports 3.3V or 5V signal levels
  • Fuse protected power output on DB-37
• Power connector (not required for minimal loads
• ODAS form factor (width is 95 mm)
• 6-32 Mounting holes

Connectors

J1 - Power

• Optional
• Pinout

1. GND
2. Vcc
3. GND
4. Vcc
5. GND

J2 - Daisy-Chained I2C

• 2x4 header, duplicated signals on each pair

1. SCL
2. SDA
3. Vcc
4. GND

J3 - Address Offset Jumpers

• Set the address offset for the MCP23017 and EEPROM
• MCP23017 base addresses are 0x20-0x21
• Card can be set to
  • 0x20-0x21
  • 0x22-0x23
  • 0x24-0x25
  • 0x26-0x27

J4 - Interrupt Out, Card Present

• Pinout

1. GND
2. INT1*
3. INT0*

• Card Present*

J5 - EEPROM Write Enable

• Install to allow writes to EEPROM
• Remove to disallow writes to EEPROM

J6 - I2C Terminators

• Install to terminate I2C lines
• Terminators should only be installed at one point in the chain at the end of the chain
• Orientation of jumpers

P1 - DB-37 Female Pinout

Schematic

• DIGIO32-I2C Schematic

Testing

• There are two card tests
  • Bounce LED test
    • Good for visual verification/debugging
    • Only tests outputs from UUT
  • Card to card test
    • More flexible/faster test
    • Tests both inputs/outputs from/to the card

Cards

• PiPicoMite02 Based Test Station
  • PiPicoMite02 Processor card
  • LED-32
• DB37RIBBON plugged into UUT
• (2) of 2x10 cables to connect between DB37RIBBON and LED-32
  • DB37-1 marked on cable end goes near P1 marked on DB37RIBBON
• LED32-1 marked on cable end goes near HDR1 marked on LED-32
• I2C cable from Arduino Based Test Station to I2C connector on UUT
• Unit Under Test (UUT)
• Check chip pin 1 orientation
• Power test card for shorts

Card Test Procedure

• Power up Test Station/UUT

Program EEPROM

• Some UUTs have Personality EEPROMs
• Run

chdir "/lbcards/ODAS_EEPROM"
load "ODASEEPROM.bas"
run

• If the UUT EEPROM is already programmed, the result is:

Found device at 0x50
Personality EEPROM contents
 Signature = ODAS
 Version = 1
 Rsvd = 0
 NumAtoms = 2
 eeplen = 96
 uuid = 0000000000000000
 Product ID = 6 (DIGIO32-I2C)
 vslen = 32
 pslen = 32
 Vendor String = LAND-BOARDS.COM
 Product String = DIGIO32-I2C
Re-write (Y/N)?

Bounce LED Test

• Cable DB-37 to LED-32 card
• Runs DIGIO32I2C-01.bas code
• Type

chdir "/lbcards/GPIO32"
load "DIGIO32I2C-01.bas"
run

• Should see the LEDs go around the LED-32 card
• Hit any key to stop (after finishing rotation)

Card-to-Card Test

• Alternate to Bounce LED test
• Runs DIGIO32I2C-02.bas code
• (2) DB37RIBBON cards
• Cables to connect two DB37RIBBON cards
• Type

load "DIGIO32I2C-02.bas"
run

• Program will halt if failure
• Prints out a pass count
• Hit any key to stop

Drivers

• GitHub repo for the DigIO32-I2C Card Arduino Driver
  • Importing an Arduino ZIP library
• GitHub repo for the DigIO32-I2C Card Arduino examples

Assembly Sheet

• DIGIO32-I2C Assembly Sheet