I2CIO16-DB25
Contents
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 female
- Easy/quick to connect/disconnect
- 16 Digital I/O lines
- (3) Power, (3) Ground
- 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 or I2C-RPT-08 - I2C Repeater
- Maximal example
- 8 I2C-RPT-08 Multiplexers
- 8 cards per multiplexer
- 16 I/O connections per card
- 1,024 I/O
- Maximal example
- I2C Termination jumpers for end of I2C chain
- Power can be 3.3V or 5V
- Easy mounting options
- Front panel cut-out
- 6-32 Mounting holes
- Boards can be stacked with 6-32 standoffs
Connectors
J1 - DB-25 I/O Connector
- DB-25 female pinout from the front of the card/connector
- Pins 1, 2, 14 are connected to Power
- Pins 12, 13, 25 are connected to Ground
- Pins 11, 15, 24 are not used
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 daisy-chain
- Side-by-side horizontal orientation (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
- INT
- SCL
- SDA
- VCC
- GND
J4 - Address Select
- Sets the I2C offset address of the card
- Install jumper for Ax = 0, remove jumper for Ax = 1
- Three bit address A1, A2
- A0
- A1
- A2
| I2C Address | J4(A2) | J4(A1) | J4(A0) |
|---|---|---|---|
| 0x0 | In | In | In |
| 0x1 | In | In | Out |
| 0x2 | In | Out | In |
| 0x3 | In | Out | Out |
| 0x4 | Out | In | In |
| 0x5 | Out | In | Out |
| 0x6 | Out | Out | In |
| 0x7 | Out | Out | Out |
- Jumper 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 Pico
MMBASIC
- I2CIO16-DB25.bas code to bounce an LED
- Runs on PiPicoMite01 or PiPicoMite02 card
BeagleBone Black Drivers
ESP32 MicroPython Drivers
PyBoard MicroPython Drivers
Linux Drivers
Mechanicals
Factory Acceptance Tests
Setup
- Unit Under Test (UUT)
- Runs on PiPicoMite02 Based Test Station
- PiPicoMite02
- LED-32 card
- I2C cable from PiPicoMite02 Based Test Station to UUT
- Cables/Adapter
- DB25RIBBON with male connector plugged into UUT
Ribbon Cable
- Cable between LED-32 and DB25RIBBON
| J1 | DB25 | I2CIO16 | LED-32 | J1 | DB25 | I2CIO16 | LED-32 | |
|---|---|---|---|---|---|---|---|---|
| 25 | 1 | GND | 26 | N/C | ||||
| 23 | 2 | GND | 24 | 14 | GND | |||
| 21 | 3 | GP0 | D15 | 22 | 15 | N/C | ||
| 19 | 4 | GP1 | D14 | 20 | 16 | GP15 | D24 | |
| 17 | 5 | GP2 | D13 | 18 | 17 | GP14 | D25 | |
| 15 | 6 | GP3 | D12 | 16 | 18 | GP13 | D26 | |
| 13 | 7 | GP4 | D11 | 14 | 19 | GP12 | D27 | |
| 11 | 8 | GP5 | D10 | 12 | 20 | GP11 | D28 | |
| 9 | 9 | GP6 | D9 | 10 | 21 | GP10 | D29 | |
| 7 | 10 | GP7 | D8 | 8 | 22 | GP9 | D30 | |
| 5 | 11 | N/C | 6 | 23 | GP8 | D31 | ||
| 3 | 12 | +3.3V | D0 | 4 | 24 | N/C | ||
| 1 | 13 | +3.3V | D1 | 2 | 25 | +3.3V | D3 |
Run Test Code
chdir "/lbcards/GPIO16" load "I2CIO16-DB25.bas" run
- Code bounces LED
Issues
Rev 1
- No issues
- Card is fully functional
