USB LIN Converter

Product and its documentation is supplied on an as-is basis and no warranty as to their suitability for any particular purpose is either made or implied. Producer will not accept any claim for damages howsoever arising as a result of use or failure of this product. This product is not intended for use in any medical appliance, device or system in which the failure of the product might reasonably be expected to result in personal injury.

Description

LIN(Local interconnect network) Usb Converter(LUC) can work both with PC without any additional drivers, it creates virtual COM port that handles LIN communication. Multiple features are supported like:

LIN 2.1 support

Monitor mode, for all frame reception, and sending single frames.

Master mode, with up to 15 frame slots

Slave mode, with up to 15 frame slots

19200/9600 option baud rate

Optical isolation for LIN

External 4.5 V to 28 V is needed for LIN network

Device size is 31x18 mm (without USB connector)

Termination resistors controlled by software

USB dfu compatible bootloader for new software

SLCAN compatible, works with LINUX socket-can and some of CAN-utils

Introduction video

Details

Board bottom view

After USB enumeration device creates virtual COM port that is used both for data transfer and converter setup. Device is be powered directly from USB, but external 4.5-28V is needed to supply LIN transceiver. Board layout is shown below.

Drivers

For proper work on Windows you need to install virtual com drivers from ST site or download from here .

COM port Commands

Below is list of all available commands. USART baud rate is virtual so can be any. All commands are ASCI format. Commands are terminated with newline character CR (0xD). On error the device responses with 0x7 value.

Command	Description
O	Opens device in master mode.
C	Close LIN port on device, frame will not be received.
Sx	Baud rate selection: S2 - 9600 S1,S3-S8 - 19200
V	Get hardware version.
v	Get firmware version.
N	Get serial number.
L	Open device in, slave mode, for LIN slave simulation.
l	Open device in, monitor mode, message analyzer mode, with single frame sending possibility .
tiiildd	In Monitor mode, transmits full header and data frame. In Master mode, updates table set with new frame In Slave mode, updates table set with new data 0ii: Identifier in hexadecimal format (000-0FF) l: Data length (0-8) dd: Data byte value in hexadecimal format (00-FF)
r0iil	In Monitor mode, transmits header only with set ID and Length, subscribed slave should answer the header. In Master mode, puts or updates table set with this id for continuous sending. In Slave mode, updates table set with reception slot Proper timing is set according to LIN standard. 0ii: Identifier in hexadecimal format (000-0FF) l: Data length (0-8)
r1ff0	In Master mode, starts sending frames from table.
r2ff0	In Master, Slave mode, clears schedule table.
xm	Swich checksum for classic x2 for enhanced x1

Example workflow for Monitor Mode

000005: C  (send close command) 

000006: v  (ask for firmware version)

000007: v0102 (get version number from device)

000008: V   (ask for hardware version)

000009: V0101

000010: N   

000011: N16000000

000012: W2D00

000013:

000014: S0  (speed setting, 19200)

000015: 

000016: L   (open in monitor mode)

000017: 

000018: r0128 (transmit header with 8 data bytes request, id 0x12)

000019: z

000020: t01280011223344556677 (slave responded for header request with 8 byte data frame)

Example workflow for Master Mode

000015: 

000016: O   (open in master mode)

000017: 

000018: r0018 (add to schedule table frame transmission header with 8 data bytes request, id 0x01)

000019: z

000018: r0022 (add to schedule table frame transmission header with 2 data bytes request, id 0x02)

000019: z

000020: t01280011223344556677 (add to schedule table frame transmission header + data (slave task) with 8 data bytes, id 0x12)

000021: z

000022: r1ff0 (start sending frames)

000023: z

Custom frame timing

You can tweek the timing in master mode just type upper letter T instead of t or R instead of r then format is similar

T 0 id id t1 t1 t2 t2 len d0 d0 d1 d1 d2 d2 

where:
id - frame id same as standard
t1 - frame offset in ms
t2 - response wait time in ms
len - frame length
d0 .... - data
example frame with id 1 5 ms offset and 1 ms wait time after sending 3 bytes of data AA BB CC

T0005013AABBCC

FAQ

What is the cheapest USB LIN bus converter that works on Linux?

The uCanDevices USB LIN Converter (uLC) is an open-source LIN dongle around $27 that enumerates as a USB CDC virtual COM port on Linux, macOS and Windows. It speaks an SLCAN-style ASCII protocol so it bridges into SocketCAN via slcand and works with parts of can-utils. No proprietary driver is required.

Does it support master and slave mode?

Yes — monitor (full reception plus single-frame transmission), master (up to 15 scheduled slots) and slave (up to 15 slots for slave simulation). Modes are selected over the serial port with the O, L and l commands.

Is the LIN side optically isolated from the USB host?

Yes. The LIN transceiver is optically isolated from the PC side, protecting the host from automotive transients. The LIN side needs an external 4.5–28 V supply since USB only powers the MCU.

Which LIN baud rates and LIN version are supported?

LIN 2.1, with selectable 9600 and 19200 baud. Classic and enhanced checksum are switchable with the xm command. Custom frame timing is supported in master mode.

Is the firmware open source?

Yes — firmware and hardware are open source at github.com/uCAN-LIN/LinUSBConverter. The device also has a USB DFU bootloader for in-field updates.

Hardware

We are using ST STM32f04264 microcontroller. Device PCB is designed in ki-cad. All source files are available in github here.

Software

Converter software is pure C code written in free TrueSTUDIO for STM32. All sources and releases with compilation instructions are available in our github here.

Uploading new software

ULC have got embedded DFU USB bootloader for usage see UsbCANConverter(UCCB) project see tutorial.

Tools

Python support

There is dedicated python library for LUC, (uCANLinTools) with: LDF parsing support, LIN frame (PIDs) encoding/decoding, LIN master, slave support. See uCANLinTools for more info, source code and examples see here

Serial port

You can use LUC on any operating system with serial terminal program like for example putty. Description of all available commands can be found in About section. All commands are the same as for USB-CAN converter so all tools can be reused, see UCAN USB-CAN converter project for libs and tools. LUC is also compatible with LINUX CAN-UTILS and SOCKET CAN. Device have its own terminal, uCCBViewer.