ijmeca/esp-idf-canbus-monitor

Monitor Canbus traffic

esp-idf-CANBus-Monitor

Monitor Canbus traffic.

Background

Windows application for monitoring CANBus is published here.
This tool is designed to be used with this hardware.

So, I made the hardware side with ESP32.

Application structure

+-------------+           +-------------+           +-------------+            +-------------+
| Windows     |           |   USB-TTL   |           |             |            | SN65HVD23x  |
| Application |<--(USB)-->|  Converter  |<--(TTL)-->|    ESP32    |<--(TWAI)-->|   CAN-BUS   |<--(CAN BUS)-->CAN Network
|             |           |             |           |             |            | Transceiver |
+-------------+           +-------------+           +-------------+            +-------------|

Software requirement

esp-idf v4.2-dev-2243 or later.
Use twai(Two-Wire Automotive Interface) driver instead of can driver.

Hardware requirements

1. Windows PC
   Windows applications can be downloaded here.

   • V7.10
   • V7.20
   • V8.00

2. USB-TTL Converter
   ESP32 development board has USB.
   This USB connects to Linux and is used for writing the firmware and displaying the LOG.
   Need converter to connect with Windows PC.

Converter		ESP32
RXD	--	GPIO4
TXD	--	GPIO5
GND	--	GND

3. SN65HVD23x CAN-BUS Transceiver

SN65HVD23x		ESP32
D(CTX)	--	GPIO21
GND	--	GND
Vcc	--	3.3V
R(CRX)	--	GPIO22
Vref	--	N/C
CANL	--		To CAN Bus
CANH	--		To CAN Bus
RS	--	GND(*1)

(*1) N/C for SN65HVD232

4. Termination resistance
   I used 150 ohms.

Test Circuit

   +-----------+ +-----------+ +-----------+ 
   | Atmega328 | | Atmega328 | |   ESP32   | 
   |           | |           | |           | 
   | Transmit  | | Receive   | | 21    22  | 
   +-----------+ +-----------+ +-----------+ 
     |       |    |        |     |       |   
   +-----------+ +-----------+   |       |   
   |           | |           |   |       |   
   |  MCP2515  | |  MCP2515  |   |       |   
   |           | |           |   |       |   
   +-----------+ +-----------+   |       |   
     |      |      |      |      |       |   
   +-----------+ +-----------+ +-----------+ 
   |           | |           | | D       R | 
   |  MCP2551  | |  MCP2551  | |   VP230   | 
   | H      L  | | H      L  | | H       L | 
   +-----------+ +-----------+ +-----------+ 
     |       |     |       |     |       |   
     +--^^^--+     |       |     +--^^^--+
     |   R1  |     |       |     |   R2  |   
 |---+-------|-----+-------|-----+-------|---| BackBorn H
             |             |             |
             |             |             |
             |             |             |
 |-----------+-------------+-------------+---| BackBorn L

      +--^^^--+:Terminaror register
      R1:120 ohms
      R2:150 ohms(Not working at 120 ohms)

Install

git clone https://github.com/nopnop2002/esp-idf-CANBus-Monitor
cd esp-idf-CANBus-Monitor
make menuconfig
make flash

Configure

How to use

• Write firmware to ESP32.
• Connect ESP32 and Windows PC using USB-TTL Converter.
• Start a Windows application.

User manual

See here.

CAN receive message transfer

CAN receive messages are broadcast using UDP.
You can use recv.py.