View source for Getting started with CAN bus and an Arduino Uno

You can talk to CAN bus devices relatively cheaply using an Arduino Uno.

You will need the following:
* An Arduino Uno R3 board

*An MCP2515-based Arduino CAN shield[[File:Arduino Uno CAN bus shield.jpg|alt=EF02037 style MCP2515 Arduino Uno CAN bus shield|thumb|EF02037 style MCP2515 Arduino Uno CAN bus shield]]
* Two 120 ohm resistors

Here are the steps:
== Configure your Arduino IDE ==
Download and install the [https://www.arduino.cc/en/Main/Software Arduino IDE] on your computer<br>
Connect your Arduino board with a USB cable<br>
''Tools -> Port'' make sure your Arduino board is selected<br>
''File -> Examples -> 01.Basics -> Blink''<br>
''Sketch -> Upload''<br>
Hopefully you have a blinking light on your Arduino board. This means your IDE is working.
== Configure your CAN bus shield ==
[[File:CAN bus shield fitted to Arduino Uno.jpg|alt=CAN bus shield fitted to Arduino Uno|thumb|CAN bus shield fitted to Arduino Uno]]
Disconnect the Arduino board, assemble your CAN shield and fit it to the Arduino<br>
Connect your Arduino board with a USB cable<br>
Download the CAN library ZIP file from here https://github.com/Seeed-Studio/CAN_BUS_Shield<br>
''Sketch -> Include Library -> Add .ZIP Library...'' & choose the ZIP file you just downloaded<br>
''File -> Examples -> CAN-BUS Shield ->'' receive_check<br>
''Tools -> Serial Monitor'' change the baud rate to 115200<br>
''Sketch -> Upload''<br>
Hopefully you will see the following on the Serial Monitor:<br>
<code>Enter setting mode success<br> 
set rate success!!<br>
Enter Normal Mode Success!!<br>
CAN BUS Shield init ok!</code>'''<br>'''
If you see:<br>
<code>Enter setting mode fail<br>
CAN BUS Shield init fail<br>
Init CAN BUS Shield again</code>'''<br>'''
try changing <code>SPI_CS_PIN</code> from 9 to 10<br>
== Talk to your device over CAN ==
[[File:Arduino CAN bus shield connected to Isabellenhütte IVT-S.jpg|alt=Arduino CAN bus shield connected to Isabellenhütte IVT-S|thumb|Arduino CAN bus shield connected to Isabellenhütte IVT-S]]
[[File:CAN bus messages on serial console.jpg|alt=CAN bus messages on serial console|thumb|CAN bus messages on serial console]]
Now connect and power up your CAN bus device. You'll need a 120 ohm resistor at each end of the bus (making 60 ohms total impedance). Sometimes the termination resistor is built in, sometimes it isn't. Check it with a multimeter across the CAN bus terminals.<br>
When there is CAN bus traffic, you should see it appear on the serial monitor and the INT light should flash on your CAN bus shield.<br>
If nothing happens, check your CAN bus speed matches the device you are connected to. For my Isabellenhütte IVT-S, I had to change <code>CAN_500KBPS</code> to <code>CAN_1000KBPS</code> to get it to work - even though the IVT-S is communicating at 500Kbps.<br>

[[Category:CAN]] [[Category:Introduction]] [[Category:Tutorials]]