# BPI-M1 CAN Bus

为了您能正确的连接 CAN4LINUX 到 Banana Pi （BPI-M1）中，你需要阅读全志A20硬件手册中相关CAN的章节。CAN4LINUX 是基于字符驱动的Linux驱动程序。已经能在x86和嵌入式平台中运行如 Freescale FlexCAN (i.MX) 或者是Xiliny Zynq 平台。

关于在A20上运行CAN总线的详细文档请参考如下：\
<https://dl.linux-sunxi.org/A20/CAN%20Bus1.pdf>

**下面教程就是如何在Bananian 15-01中使用CAN 总线：**

感谢selqcir 分享他的成果：

* 下载并且烧录"bananian-1501.img" 到一张至少8GB的 tf卡上。
* 使用"bananian-config"命令扩展根文件系统。
* 安装缺少的扩展包：

  \`\`\`apt-get install git\
  apt-get update\
  apt-get upgrade\
  reboot'''
* 获取 Bananian 缺少的包，并且安装这个package:\
  '''git clone <https://github.com/Bananian/linux-bananapi>\
  apt-get install build-essential u-boot-tools uboot-mkimage\
  apt-get install libusb-1.0-0 libusb-1.0-0-dev git wget fakeroot kernel-package zlib1g-dev libncurses5-dev\
  apt-get install subversion'''
* 编译内核:\
  '''cd linux-bananapi\
  make menuconfig'''
* Exit without saving when menu appears\
  '''zcat /proc/config.gz > /root/linux-bananapi/.config\
  make uImage modules\
  make INSTALL\_MOD\_PATH=output modules\_install'''
* At this step, kernel should be compiled and "Module.symvers" should be available
* Then rename modules and firmware provide by Bananian, and replace by the new one.\
  '''mv /lib/modules /lib/modules.old\
  mv /lib/firmware /lib/firmware.old\
  mv /root/linux-bananapi/output/lib/modules /lib/modules\
  mv /root/linux-bananapi/output/lib/firmware /lib/firmware'''
* Same for uImage:\
  '''mount /dev/mmcblk0p1 /mnt\
  cd /mnt\
  mv uImage uImage.old\
  mv /root/linux-bananapi/arch/arm/boot/uImage /mnt\
  reboot'''
* Create link for further build:\
  '''cd /lib/modules/3.4.104/\
  ln -s /root/linux-bananapi build\
  cd \~'''
* Get Can4Linux and build it:\
  '''svn checkout <https://svn.code.sf.net/p/can4linux/code/trunk> can4linux-code\
  cd /root/can4linux-code/can4linux/\
  make TARGET=BANANAPI'''
* Install module for each startup of the board:\
  '''insmod can4linux.ko\
  cp can4linux.ko /lib/modules/3.4.104/kernel/net/can/\
  depmod -A -v\
  modprobe -v can4linux\
  echo "" >> /etc/modules ; echo "can4linux" >> /etc/modules\
  reboot'''
* Build CAN example\
  '''apt-get install swig\
  apt-get install python-dev\
  cd can4linux-code/can4linux-examples/'''
* Update CAN speed and device in file "pyCan-example.py"

  ex:\
  \`\`\`

  **setting the device number**

  device = 0\
  defaultBaudrate = '250'\`\`\`
* Connect CAN transceiver and CAN bus, and check with for example:

```
   python pyCan-example.py
```

That's all

With this method, kernel version is "Linux bananapi 3.4.104" instead of "Linux bananapi 3.4.104+", because i was unable to find same sources than Bananian 15-01 , but CAN bus work !

Feel free to comment or update.