CANchecked CFE18 Gen1 - Universal CAN ECU Add-on

CFE18 - CAN Bus Switching Board

CFE18 stands for "CAN Bus Function Extension" or, colloquially, "CAN Switching Board". Why do you need this module?

CAN Bus connections in your vehicle sometimes present significant challenges. Especially in motorsport applications, where electronics need to be housed in the steering wheel and information from rotary or push buttons needs to be transmitted via the CAN Bus.

CANchecked now offers a small add-on module that provides 17 inputs: 8 for switches (low-side) and 9 for analog inputs (0-5 V signal). It also includes a voltage converter for connection to a 12 V automotive electrical system.

The board also features 3 low-side switching outputs with a maximum capacity of 0.5 A.

CFE18 Hardware

At just 29 x 27 mm, the board is very compact and fits into any space. The pin spacing is 2.54 mm; for power, it is 3.81 mm.
We have added a mounting hole that can be used for screw fastening.

CFE18 - CAN Bus Termination

The board includes a solder jumper.

By closing this jumper, the 120 Ohm CAN Bus termination is activated. By default, the solder jumper is open.

Motorsport Steering Wheel

One possible application would be a motorsport steering wheel. The image shows the approximate size, with a diameter of 50 mm at the center of the steering wheel. With only 4 connections via a coiled cable, various signals can be transmitted via the CAN Bus.

Connection Options

With the CFE18, you can connect switches and potentiometers (adjustment knobs).

It is also possible to connect sensors such as oil pressure, fuel pressure, boost pressure, exhaust back pressure, and integrate them into a custom housing.

Digital Outputs

The CFE18 has three digital outputs. These can support a maximum of 500 mA and switch to ground (LOW-SIDE).
For this purpose, a CAN Bus frame is sent every 100ms (the CAN ID is configurable here; a timer is activated after a 500ms pause between frames and the outputs are deactivated): (0=inactive, 1=active)

AIN Smoothing

If the analog inputs fluctuate too much, they can be smoothed by software. This is configured individually for each analog input.

With each transmission, the analog inputs are evaluated (by default, 20 Hz). For example, if a smoothing factor of 4 is set, the average of the last 16 measurements is taken. This smooths the value but also reduces the response to fluctuations. It is crucial to find a good balance.

Configuration is done via CAN Bus.