Entrée USB-C CAN Interface

May 5, 2026 · View on GitHub

The Entrée is a USB-C CAN/CAN FD (up to 5 Mbit/s) interface, designed to be fully feature-compatible with the CANnectivity firmware firmware and Linux SocketCAN.

Entrée - like a Canapé but tastier...yes the logo is, and name was, Canapé but I didn't want to face a Trademark dispute over an acute e for a hobby project...

Entrée PCBA

Features

  • Compatiable with CANnectivity firmware; Zephyr based gs_usb.
  • USB-C connection for use with modern hardware.
  • Sotware and hardware switched control of 120 Ω termination resistor.
  • Sotware and hardware switched control of VBUS to VDD connection for powering from USB.
  • USB DFU and TagConnect 6-pin ISP for use as a development tool.
  • FDCAN2 test points that with external transceiver can be used for a second CAN channel.
  • USART test points for SLCAN without USB.
  • Alternative JST SM04B (Qwiic/STEMMA) connector footprint for use with commonly available cables.
  • Silkscreen art 🎨!
  • 3d printed case

Purchase

Usage

Note

The README has been updated for Entrée V2 which has a different hardware design to the original V1. The V1 supported candleLightFW and had USB-PD. The original V1 design is still available on the V1 tag

Hardware Connection

The primary CAN connection is a Molex Picoblade 53261-0471.

The connector was selected because they are commonly used on Drones and so Picoblade to 0.1" header cables can also be easily obtained:

Alternatively, one can obtain pre-crimped female cable assemblies 15134-0402 or female 4-pin housing 51021-04 for custom cabling.

A secondary unfitted JST SM04B (otherwise known as Qwiic/STEMMA) footprint is available on the bottom of the board if one wishes to use those commonly available cables instead. JST pre-crimped part is A04SR04SR30K152A.

Wiring Example

Below is a wiring example showing the Entrée Picoblade and JST pinout. A Black Magic 0.1" female header cable is connected to the Picoblade and standard STEMMA QT connected to the secondary JST header. Note both cable colouring is non-standard due to optimal board layout.

Entrée wiring diagram

Software

A Vagrant virtual machine environment is provided in the ./linux-vm folder for those on non-Linux hosts or who want a pre-configured environment. Install Vagrant and VirtualBox and then setup the machine from within the ./linux-vm folder with the vagrant up command.

Linux SocketCAN

Entrée comes with CANnectivity firmware which is intended for use with a Linux host. Most Linux distributions include the gs_usb driver and can kernel modules by default so getting started is very easy.

The below assume a single CAN interface is present with default name can0 - if multiple interfaces are present then the name may be different and can be found with ip link.

Create CAN network interface [ref]

sudo ip link set can0 type can bitrate BIT_RATE # where BIT_RATE is the CAN bus speed in b/s
sudo ip link set up can0

Control Termination Resistor

sudo ip link set dev can0 type can termination 0  # Disable termination resistor on can0
sudo ip link set dev can0 type can termination 120 # Enable 120 ohm termination resistor on can0

ip link set can0 type can help
ip -details -statistics link show can0 # Show detailed information about can0 including termination resistor status

CLI

Install can-utils using one's package manager and then various command line tools are available.

cansend can0 999#DEADBEEF   # Send a frame to 0x999 with payload 0xdeadbeef
candump can0                # Show all traffic received by can0
canbusload can0 500000      # Calculate bus loading percentage on can0
cansniffer can0             # Display top-style view of can traffic
cangen can0 -D 11223344DEADBEEF -L 8    # Generate fixed-data CAN messages

See the can-utils README for more.

Cangaroo GUI

The Cangaroo GUI can be compiled for Linux hosts. See Cangaroo.

Windows

To use the default firmware on Windows, one can use Cangaroo: Pre-compiled Win32 binary.

Alternatively, to use SocketCAN one can use the pre-configured virtual machine explained at the start of the Software section.

Python

The python-can module supports 'socketcan' (Linux host) and 'gs_usb' interfaces so options for all hosts are covered - see the configuration page.

Paired with the cantools module, one has access to powerful CLI tools and scripting for CAN bus operations including use with database definition files.

Both modules are pre-installed in the Vagrant virtual machine.

DIP Switches

Note

The DIP switches override software control.

SwitchDecimalSet Action
11Enable VBUS -> VDD.
22Enable 120 ohm CAN_H/CAN_L termination resistor

JBR Engineering Research Ltd