EMUC-B202 SocketCAN Driver and Uspace Tool

Build Driver and Util

Please install kernel development packages on your machine and simply type 'make' command in root folder of this packge.

There should be two output files:

• src/emuccan.ko : kernel driver of emuc socket can
• src/emucd : user-space tool for enable emuc socket can

Usage and Example

Here is a example to use emuccan socket CAN.

root@host# insmod emuccan.ko
root@host# emucd -s6 ttyACM0 can0 can1
root@host# ip link set can0 up
root@host# ip link set can1 up
root@host# cansend can0 5A1#11.22.33.44.55.66.77.88
root@host# candump can1

The detail usage of 'cansend' and 'candump', please refer the open source project 'can-utils' (https://github.com/linux-can/can-utils).

You can specified the CAN speed for two channels when execute 'emucd' daemon, type 'emucd -h' for help.

root@host# emucd -s6 /dev/ttyACM0  (250 KBPS on both channel)
root@host# emucd -s45 /dev/ttyACM0 (100 KBPS on ch1, 125 KBPS on ch2)

Troubleshooting

If the can device did not show up after 'emucd' is executed. Please check your system log to see if there is any error message reported by emuccan or emucd.

root@host# tail -n 100 /var/log/syslog (Ubuntu)
root@host# tail -n 100 /var/log/message (CentOS)

Or, you can try to run 'emucd' in foreground to see if there is any error reported.

root@host# emucd -F -s6 /dev/ttyACM0

There cannot be two EMUCD daemon running with same TTY device. You must kill the previous one before running a new one on same device.

A note on device names

Unfortunately, emucd_64 is hardcoded(!) to only accept certain device names defined in an extern variable called comports (search inside lib_emuc2_64.a object). Yup. Go figure. So we hardcode it to /dev/ttyCAN0 for now. Even worse, we used to use /dev/ttyACM9 but that was causing issues with un-plugging and replugging enough tty devices that our symlink was interferring with the dynamic kernel defined names (on the 10th replug).

Debian and System Install

This version of the library also includes a debianization which will build a package and install it on Ubuntu systems.

To build the library and create the repo use:

• make clean
• Bionic-Melodic:
  • export KERNEL_VER=$(uname -r) # 5.3.7nlb
• Focal-Noetic (Stock Kernel)
  • apt install linux-headers-5.4.0-96-generic # This can change depending on which kernel you want to build
  • export KERNEL_VER=$(uname -r) #stock kernel
  • export VER_SUFFIX=greenzie #OPTIONAL if you want to brand version
• export KERNEL_SRC=/usr/src/linux-headers-${KERNEL_VER}/
• make

This will generate two files, emucd_64 (a userspace binary) and emuc2socketcan.ko (a kernel module). The latter needs be rebuilt for each kernel (even new configurations of the same kernel version), but the former should be reusable.

To build the debian package, run:

• mkdir build
• cd build
• cmake ..
• make
• cpack

You should now have a debian called emuccan-b202_2.7.1-1.deb.

The trailing -1 is a version you can bump inside CMakeLists.txt when rebuilding the same source for a new kernel version.