# BPI-R1 CAN Bus

In order to port [can4linux](https://sourceforge.net/projects/can4linux/) to the BananaPi, the CAN module description is needed from the A20 hardware manual. can4linux is a character-driver-based Linux driver used already on desktop PCs and embedded platforms like Freescale FlexCAN (the i.MX series of micro controllers) or Xiliny Zynq.

There is a more detailed document about CAN on the A20 at [https://dl.linux-sunxi.org/A20/CAN Bus1.pdf](https://dl.linux-sunxi.org/A20/CAN%20Bus1.pdf)

**This is a tutorial for using CAN BUS on bananapi with bananian 15-01**

Thank selqcir share this example:

* Download and install "bananian-1501.img" into 8 GB SDCard.
* Expand the root file system using "bananian-config"
* Install missing package:

  ```
  apt-get install git
  apt-get update
  apt-get upgrade
  reboot
  ```
* Get last bananian available, and continu to install missing 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
  ```
* Build kernel:

  ```
  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.


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