CANBED M4

Introduction¶

CAN Bus is a common industrial bus because of its long travel distance, medium communication speed and high reliability. It is commonly found on modern machine tools, such as an automotive diagnostic bus. This CANBed M4 is the latest board of the CANBed family, with the ATSAME51G19A mcu and MCP2542FD CAN transceiver to achieve the CAN-FD capability.

Click to get a DB9 to OBD-II cable.

CANBed Family¶

VRESION	CANBed V1	CANBed FD	CANBed M0	CANBed M4
PICTURES
MCU	Atmega32U4	Atmega32U4	ATSAMD21G18	ATSAME51G19A
CORE	AVR 8 bit	AVR 8 bit	ARM Cortex M0+ 32bit	ARM Cortex M4 32bit
PROTOCOL	CAN2.0	CANFD & CAN2.0	CAN2.0	CANFD & CAN2.0
CLOCK	16MHz	16MHz	48MHz	120MHz
FLASH	32KB	32KB	256KB	512KB
RAM	2.5KB	2.5KB	32KB	192KB
PRICE	$24.9	$19.9	$24.9	$19.9
LINK	GET ONE NOW	GET ONE NOW	GET ONE NOW	GET ONE NOW

CAN BUS PRODUCTS LIST OF LONGAN LABS¶

We have made a lot of can bus products, you can get more information through the following list, so as to choose a product suitable for you.

PRODUCT NAME	LINK	PRICE	MCU	CHIP	PROTOCOL
Serial CAN Bus Module	LINK	$19.9	ATMEGA168PA	MCP2515	CAN2.0
I2C CAN Bus Module	LINK	$19.9	ATMEGA168PA	MCP2515	CAN2.0
OBD-II Serial CAN Bus Dev Kit	LINK	$20.9	ATMEGA168PA	MCP2515	CAN2.0
OBD-II CAN Bus GPS Dev Kit	LINK	$29.9	ATMEGA32U4	MCP2515	CAN2.0
OBD-II CAN Bus Basic Dev Kit	LINK	$24.9	ATMEGA32U4	MCP2515	CAN2.0
CAN-FD Shield	LINK	$12.9	NO MCU	MCP2517FD	CAN-FD
CAN Bus Shield	LINK	$5.9	NO MCU	MCP2515	CAN2.0
CANBed	LINK	$24.9	ATMEGA32U4	MCP2515	CAN2.0
CANBed-FD	LINK	$19.9	ATMEGA32U4	MCP2517FD	CAN-FD
CANBed M0	LINK	$24.9	ATSAMD21	MCP2515	CAN2.0
CANBed M4	LINK	$19.9	ATSAME51	-	CAN-FD
OBD-II RF Dev Kit	LINK	$19.9	ATmega168PA	MCP2515	CAN2.0

Features¶

CAN-FD and CAN2.0
ATSAME51G19A 32bit Cortex M4 core
512 KB flash, 192KB RAM
Industrial standard 9 pin sub-D connector or 4PIN Terminal Connector
OBD-II and CAN standard pinout selectable at sub-D connector
2x4Pin Connector compatable with Grove system
Size: 56x41mm

Specifications¶

MCU: ATSAME51 32bit Cortex M4 core
Clock speed: 120MHz
Flash memory: 512KB
RAM: 192KB
EEPROM: No EEPROM
Input voltage: 7~28V
Output Current @ 5V: 1A
Input interface: Sub-D as well as Terminal

Hardware Overview¶

Part List¶

Note

In consideration of convenient transportation and cost reduction, there are some materials that you need to solder by hand. If you don't have soldering iron tools, you can also ask our engineers to do it for you. After you place an order, email info@longan-labs.

CANBed M4 PCBA
sub-D connector
4PIN Terminal
4PIN 2.0 Connector x 2
9x2 2.54 Header x 1
3x3 2.54 Header x 1

Pin out¶

1.9x2 IO Pin OUT:

The IO of Atsame51 is list out here.

2.ATSAME51G19A:

Cortex M4 core controller

2.Reset Button:

Reset the on-board Atmega chip.

3.Micro USB connector for programming

4. SPI Interface

5.CAN RX/TX Indicator

6.sub-D connector or Terminal for CAN Bus

D-Sub CANbus PinOut

pin#	Signal names	Signal Description
1	Reserved	Upgrade Path
2	CAN_L	Dominant Low
3	CAN_GND	Ground
4	Reserved	Upgrade Path
5	CAN_SHLD	Shiled, Optional
6	GND	Ground，Optional
7	CAN_H	Dominant High
8	Reserved	Upgrade Path
9	CAN_V+	Power, Optional

7.Switch for the 120Ω terminal resistor for CAN Bus

If you use this board on the end of the CAN bus, please put this switch to 120Ω. For more detail about the CAN bus protocol, please refer to the NI CAN Physical Layer and Termination Guide

8.Grove connector for UART

9.Grove connector for I2C

DB9 connector¶

The DB9 interface of CAN Bus has two different protocols, OBD and CAN Open. Their definition is as follows,

pin#	OBD(default)	CAN OPEN
1	GND	N.C
2	GND	CAN_L
3	CANH	GND
4	N.C	N.C
5	CANL	GND
6	N.C	N.C
7	N.C	CAN_H
8	N.C	N.C
9	CAN_V+	CAN_V+

If you want to use the OBD protocol, you don't need to make any changes to the hardware.

If you need to use the CAN Open protocol, first we look at the back side of the PCB board, you can see the Pads below,

These pads are connected to the OBD side by default. We have to prepare a knife to disconnect the OBD side, and then use an electric soldering iron to solder the CAN Open side of the pads.

Arduino IDE Setup¶

First download the Arduino IDE from https://www.arduino.cc/en/Main/Software. Arduino IDE can be installed and run on Windows, Linux, and Mac OS X operating systems. Download the installer or zip file (Windows only) and install (if you have the zip file, extract it to your Windows computer’s hard drive) it on your operating system.

Once finished, start the Arduino IDE.

Copy and paste the link below into the Additional Boards Manager URLs option in the Arduino IDE preferences (File > Preferences).

https://raw.githubusercontent.com/Longan-Labs/LONGAN-SAME-TOOLS/master/package_longan_samd_index.json

Enter longan to install the latest Longan SAME board

Usage¶

Arduino Code¶

We provide an Arduino library for CANBed M4.

There're many examples for the library, which is consist of,

CAN_20_Send - How to send a frame to CAN Bus 2.0
CAN_20_Recv - How to recv a frame from CAN Bus 2.0
CAN_FD_Send - How to send a frame to CAN FD
CAN_FD_Send - How to recv a frame from CAN FD

Rescue the bricked board¶

Sometimes due to some strange reasons, your board can no longer burn any program, and the USB cannot be recognized. At this time, you can save your board by the following methods

First of all you need a J-Link tool, if you don't have it, you can get one from Longan Labs.

Please folow below steps.

Get a J-Link tool
Download the J-Flash software
Install the J-Link Software, then you will get a J-Flash tool.
Download the bootloader file.
Open J-Flash software, Click to select the MCU.

6.Find SAME51G19A

7.Point to the bootloader file

8.Connect SWD interface to the board.

9.Click on Program Device, if everything is ok, you saved the board now.

FAQ¶

The RX/TX led light up and never turn off

Check if the baudrate of CAN Bus is setting correct
Try turning on/off the switch for the terminal resistor
Cehck if CANH and CANL is connected correct

How to find the tech support

Please feel free to contact joney.sui@longan-labs.cc if you need more help.