Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/leggedrobotics/tcan

A library to communicate to devices connected through CAN, EtherCat, USB or TCP/IP.
https://github.com/leggedrobotics/tcan

can communication ethercat usb

Last synced: about 2 months ago
JSON representation

A library to communicate to devices connected through CAN, EtherCat, USB or TCP/IP.

Awesome Lists containing this project

README 

        
# Threaded Communication and Networking library #



[![Build Status](https://ci.leggedrobotics.com/buildStatus/icon?job=github_leggedrobotics/tcan/master)](https://ci.leggedrobotics.com/job/github_leggedrobotics/job/tcan/job/master/)



## Overview



A library to communicate to devices connected through CAN, EtherCat, USB or TCP/IP.



### License

The source code is released under the [MIT license](LICENSE).



**Authors:** Philipp Leemann, Christian Gehring, Remo Diethelm



## Dependencies



Common



- [message_logger](https://github.com/leggedrobotics/message_logger)



Ethercat



- [soem_rsl](https://github.com/leggedrobotics/soem_interface)



## Usage



See tcan_example for an easy example how to use tcan library. tcan has two modes: synchronous and asynchronous:



- In asynchronous mode, the library creates three threads for each bus: a thread that handles incoming CAN messages, one that sends outgoing CAN messages and one that checks if devices/SDOs have timed out (sanityCheck).

- In synchronous mode, it is up to the user to call the BusManagers readMessagesSynchronous(), writeMessagesSynchronous() and sanityCheckSynchronous() functions in his main loop.



To prevent overflow of the output buffer of the SocketCAN driver (which is used by the SocketBus class) there are two possible approaches:



- Set the output queue length to a value which is large enough to hold the messages of one cycle:

    ```sudo ip link set can0 txqueuelen 100```

- Setting the SocketBusOptions::sndBufLength_ to 1 (or any other small value > 0). This sets the socket buffer size to its minimal value and will make the socket blocking if this buffer is full (which is NOT the same as the buffer of the underlying netdevice)



## Setting up the interface



### Virtual can interface



Use the ```vcan.sh``` script provided in ```tcan_utils/bash```:



```

#!bash



rosrun tcan_utils vcan.sh {start|stop|restart} 

```

e.g.



```

#!bash



rosrun tcan_utils vcan.sh start can0

```



### CAN-USB Adapter



Use the ```canusb.sh``` script provided in ```tcan_utils/bash```:



```

#!bash



rosrun tcan_utils canusb.sh {start|stop|restart} []  []

```

e.g.:

```

#!bash



rosrun tcan_utils canusb.sh start /dev/ttyUSB0 can0 -s8



rosrun tcan_utils canusb.sh stop can0

```

where ```-s8``` sets the can baud rate according to the following table:



| flag | bitrate |

|---|---|

| -s0 | 10kbit |

| -s1 | 20Kbit |

| -s2 | 50Kbit |

| -s3 | 100Kbit |

| -s4 | 125Kbit |

| -s5 | 250Kbit |

| -s6 | 500Kbit |

| -s7 | 800Kbit |

| -s8 | 1Mbit |



### Peak PCIe card



The linux kernel >= 2.6.25 supports Socketcan natively. To setup the interface, you can use



```

#!bash



sudo ip link set can0 type can bitrate 1000000 berr-reporting on

sudo ip link set can0 up

```



However the performance of the standard linux kernel driver may be bad (large gaps between can frames). Peak provides their own Socketcan driver, which can be downloaded from http://www.peak-system.com/fileadmin/media/linux/index.htm. Unpack the archive and install it with



```

#!bash



make clean

make -C driver NET=NETDEV_SUPPORT

sudo make install

```



The driver can be uninstalled with



```

#!bash



sudo make uninstall

```



To set the baudrate, the above ```ip``` command cannot be used, do the following instead:



```

#!bash



echo "i 0x001C" > /dev/pcan0

```



where ```0x001C``` is a hex representation of the baudrate, which can be taken from the following table:



| hex | bitrate |

|---|---|

| 0x7F7F | 5kbit |

| 0x672F | 10kbit |

| 0x532F | 20Kbit |

| 0x472F | 50Kbit |

| 0x432F | 100Kbit |

| 0x031C | 125Kbit |

| 0x011C | 250Kbit |

| 0x001C | 500Kbit |

| 0x0014 | 1Mbit |