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https://github.com/nopnop2002/esp-idf-can2http
CANbus to http bridge using esp32
https://github.com/nopnop2002/esp-idf-can2http
bridge can can-bus esp-idf esp32 http
Last synced: 12 days ago
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CANbus to http bridge using esp32
- Host: GitHub
- URL: https://github.com/nopnop2002/esp-idf-can2http
- Owner: nopnop2002
- License: mit
- Created: 2021-06-29T21:31:12.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2024-09-18T20:34:10.000Z (about 2 months ago)
- Last Synced: 2024-10-11T13:43:55.550Z (28 days ago)
- Topics: bridge, can, can-bus, esp-idf, esp32, http
- Language: C
- Homepage:
- Size: 55.7 KB
- Stars: 36
- Watchers: 4
- Forks: 15
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-canbus - esp-idf-can2http - CANbus to http bridge using ESP32. (Hardware / Espressif Systems (ESP8266, ESP32))
README
# esp-idf-can2http
CANbus to http bridge using esp32.
It's purpose is to be a bridge between a CAN-Bus and a HTTP-Server.
# Software requirement
ESP-IDF V5.0 or later.
ESP-IDF V4.4 release branch reached EOL in July 2024.
ESP-IDF V5.1 is required when using ESP32-C6.
# Hardware requirements
- SN65HVD23x CAN-BUS Transceiver
SN65HVD23x series has 230/231/232.
They differ in standby/sleep mode functionality.
Other features are the same.
- Termination resistance
I used 150 ohms.
# Wireing
|SN65HVD23x||ESP32|ESP32-S2/S3|ESP32-C3/C6||
|:-:|:-:|:-:|:-:|:-:|:-:|
|D(CTX)|--|GPIO21|GPIO17|GPIO0|(*1)|
|GND|--|GND|GND|GND||
|Vcc|--|3.3V|3.3V|3.3V||
|R(CRX)|--|GPIO22|GPIO18|GPIO1|(*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
# 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](http://www.ti.com/lit/an/slla337/slla337.pdf).
# Installation
```
git clone https://github.com/nopnop2002/esp-idf-can2http
cd esp-idf-can2http
idf.py set-target {esp32/esp32s2/esp32s3/esp32c3/esp32c6}
idf.py menuconfig
idf.py flash
```
# Configuration
## CAN Setting
## WiFi Setting
You can use static IP.
You can connect using mDNS.
## External HTTP Server Setting
The External HTTP Server receives CAN Bus received data.
__Note__
The Built-in HTTP Server receives CAN Bus transmittion data.
# Definition from CANbus to HTTP
When CANbus data is received, it is sent by HTTP POST according to csv/can2http.csv.
The file can2http.csv has three columns.
In the first column you need to specify the CAN Frame type.
The CAN frame type is either S(Standard frame) or E(Extended frame).
In the second column you have to specify the CAN-ID as a __hexdecimal number__.
In the last column you have to specify the HTTP-POST-Path of external HTTP server.
Each CAN-ID is allowed to appear only once in the whole file.
```
S,101,/post
E,101,/post
S,103,/post
E,103,/post
```
When a CAN frame with ID 0x101 is received, POST with the 'canid':257.
When a CAN frame with ID 0x103 is received, POST with the 'canid':259.
POST Parameter Example:
CAN-ID is a decimal number, not a hexadecimal number.
```
{"canid":257, "frame": "standard", "data": [16, 17, 18]}
{"canid":257, "frame": "extended", "data": [16, 17, 18]}
{"canid":259, "frame": "standard", "data": [16, 17, 18]}
{"canid":259, "frame": "extended", "data": [16, 17, 18]}
```
__CAN messages not registered in csv/can2http.csv are discarded and not POSTed to HTTP.__
# Definition from HTTP to CANbus
Not exist.
You can send any CAN-ID.
# Send CANBus frame using curl
CAN-ID is specified in __decimal number__.
```
$ curl -X POST -H "Content-Type: application/json" -d '{"canid": 513, "frame": "standard", "data": [16, 17, 18]}' http://esp32-server.local:8000/api/twai/send
twai send successfully
$ curl -X POST -H "Content-Type: application/json" -d '{"canid": 513, "frame": "extended", "data": [16, 17, 18]}' http://esp32-server.local:8000/api/twai/send
twai send successfully
```
CANBus reception using UNO.
---
# HTTP Server Using Tornado
```
cd $HOME
sudo apt install python3-pip python3-setuptools
python3 -m pip install -U pip
python3 -m pip install -U wheel
python3 -m pip install tornado
git clone https://github.com/nopnop2002/esp-idf-can2http
cd esp-idf-can2http
cd tornado
python3 can.py
```
You can specify the number of lines to display and the port number.
The default port number is 8000 and the default number of display lines is 20.
Redisplay every 5 seconds.
# HTTP Server Using Flask
```
cd $HOME
sudo apt install python3-pip python3-setuptools
python3 -m pip install -U pip
python3 -m pip install -U wheel
python3 -m pip install -U Werkzeug
python3 -m pip install flask
git clone https://github.com/nopnop2002/esp-idf-can2http
cd esp-idf-can2http
cd flask
python3 can.py
```
You can specify the number of lines to display and the port number.
The default port number is 8000 and the default number of display lines is 20.
Redisplay every 5 seconds.
# Brows received data Using Tornado/Flask
Open your browser and put the Server's IP in the address bar.
# Visualize CAN-Frame
## Using python
There is a lot of information on the internet about the Python + visualization library.
- [matplotlib](https://matplotlib.org/)
- [seaborn](https://seaborn.pydata.org/index.html)
- [bokeh](https://bokeh.org/)
- [plotly](https://plotly.com/python/)
## Using node.js
There is a lot of information on the internet about the node.js + __real time__ visualization library.
- [epoch](https://epochjs.github.io/epoch/real-time/)
- [plotly](https://plotly.com/javascript/streaming/)
- [chartjs-plugin-streaming](https://nagix.github.io/chartjs-plugin-streaming/1.9.0/)
# Troubleshooting
There is a module of SN65HVD230 like this.
There is a __120 ohms__ terminating resistor on the left side.
I have removed the terminating resistor.
And I used a external resistance of __150 ohms__.
A transmission fail is fixed.
If the transmission fails, these are the possible causes.
- There is no receiving app on CanBus.
- The speed does not match the receiver.
- There is no terminating resistor on the CanBus.
- There are three terminating resistors on the CanBus.
- The resistance value of the terminating resistor is incorrect.
- Stub length in CAN bus is too long. See [here](https://e2e.ti.com/support/interface-group/interface/f/interface-forum/378932/iso1050-can-bus-stub-length).
# Reference
https://github.com/nopnop2002/esp-idf-candump
https://github.com/nopnop2002/esp-idf-can2mqtt
https://github.com/nopnop2002/esp-idf-can2usb
https://github.com/nopnop2002/esp-idf-can2websocket
https://github.com/nopnop2002/esp-idf-can2socket
https://github.com/nopnop2002/esp-idf-CANBus-Monitor