User Tools

Site Tools



CP-IO22 - IO Board Accessory for the ComfilePi

The CP-IO22 is an IO board accessory for the ComfilePi consisting of 22 IO (11 inputs, 11 outputs) screw terminals, and corresponding indicator LEDs. It can be mounted to the rear panel of the ComfilePi.


C#/VB.Net Control Example

The following is an example project illustrating how to program the CP-IO22 in C# or VB.Net using the Mono Framework.

Download Source Code

This example PInvoke's the pigpio library. For more information see the PInvoke documentation and the pigpiod C interface documentation

.NET 5 drivers can be found at the .NET IoT Libraries API Reference.

Pin Map

The CP-IO22 pins are connected to the ComfilePi's GPIO header as shown below.

Inputs: GPIO 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16
Outputs: GPIO 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27

Specifications and IO Circuitry

  • Input Voltage: 5VDC (powered by ComfilePi's 5V pin)
  • Current Rating: 400mA or more
  • Humidity: 35 ~ 85% RH
  • Temperature: -30 ~ 60 ℃
  • Size: 128mm X 78mm


  • Voltage Range: 12 ~ 24V
  • Absolute Min/Max Voltage Range: 3.3 ~ 28V
  • Response Time: 5ms
  • Input OFF Level: <1.8VDC
  • Input ON Level: >2.5VDC
  • Indicator LED OFF Level: <4.5V
  • Indicator LED ON Level: >5.0V


  • DC Output Sink (NPN) x 11
  • Maximum Output Voltage: 30VDC
  • Response Time: 10ms
  • Current: 150mA

Setting the Initial IO State

It may be necessary to modify the ComfilePi's initial GPIO output state to prevent the ComfilePi from turning the outputs ON when the ComfilePi boots.

Modify the ComfilePi's /boot/config.txt file with the following configuration to set the initial IO state. See GPIO control in config.txt for more information.


COMFILE Technology's Documentation Library

cp-io22/index.txt · Last modified: 2021/06/29 10:21 by COMFILE Technology