esp-idf-candump

Example code for CAN receive using ESP-IDF.
ESP-IDF contains three example for TWAI, but you need two ESP32s running master and slave, or master and listen_only at the same time.
So, I made a reception-only tool with Raspberry or Arduino as the sender.

Software requirement

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

Hardware requirements

SN65HVD23x CAN-BUS Transceiver

SN65HVD23x		ESP32	ESP32-S2	ESP32-C3
D(CTX)	--	GPIO21	GPIO17	GPIO9	(*1)
GND	--	GND	GND	GND
Vcc	--	3.3V	3.3V	3.3V
R(CRX)	--	GPIO22	GPIO18	GPIO10	(*1)
Vref	--	N/C	N/C	N/C
CANL	--				To CAN Bus
CANH	--				To CAN Bus
RS	--	GND	GND	GND	(*2)

(*1) You can change using menuconfig. But it may not work with other GPIOs.

(*2) N/C for SN65HVD232

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)

NOTE
3V CAN Trasnceviers like VP230 are fully interoperable with 5V CAN trasnceviers like MCP2551.
Check here.

Installation for ESP32

git clone https://github.com/nopnop2002/esp-idf-candump
cd esp-idf-candump
idf.py set-target esp32
idf.py menuconfig
idf.py flash

Installation for ESP32-S2

git clone https://github.com/nopnop2002/esp-idf-candump
cd esp-idf-candump
idf.py set-target esp32s2
idf.py menuconfig
idf.py flash

Installation for ESP32-C3

git clone https://github.com/nopnop2002/esp-idf-candump
cd esp-idf-candump
idf.py set-target esp32c3
idf.py menuconfig
idf.py flash

Configuration

You have to set this config value with menuconfig.

CAN Bitrate
CTX GPIO number
CRX GPIO number

Acceptance Filter

The explanation about the acceptance filter is available here.
There are diagrams of Bit layout of single filter mode and Bit layout of dual filter mode, but they are described in Right side MSBit.
I've never seen a Right side MSBit before, so I thought it was a Left side MSBit.
I was very confused.

Reference

https://github.com/nopnop2002/esp-idf-can2http

https://github.com/nopnop2002/esp-idf-can2mqtt

https://github.com/nopnop2002/esp-idf-can-browser

PyroMix62/esp-idf-candump