New generic module supporting CAN232/CANUSB/LAWICEL protocol

[DePierre]

Hi there,

I've been interested with using CANToolz with my Arduino+Seeed CAN-BUS shield. I've flashed my Arduino with https://github.com/latonita/arduino-canbus-monitor, which implements CANUSB protocol.

I've seen that the hw_USBtin.py module also implements the CANUSB protocol somehow but I couldn't easily remove the things that were specific to USBtin to make it work with my setup.

So I've decided to have a look to implement a more generic module that should be able to support all hardware implementing CAN232/CANUSB/LAWICEL protocol. It works quite okay-ish. You can receive CAN frames and send CAN232 commands at the same time without missing too many frames. I've plugged the new module with mod_stat and it works quite well.

I have to be honest though, there are very likely a lots of bugs. I've tried to have a look to implement some unit tests for it for looking at the other unit tests, I'm not sure to understand how I should proceed.

Also, due to parallel processing I suppose, there are some unexpected corruptions that affect the received frames, which raised quite some unexpected exceptions during the development of the module. I've tried to have it as stable as possible for the initial version but some work remains IMO.

This new module implements the following CANUSB commands:

• V -- Get version number
• v -- Get detailed firmware version number
• N -- Get serial number
• O -- Open channel
• L -- Open channel in read only
• C -- Close channel
• S -- Speed of the channel
• F -- Get status flag
• Z -- Switch timestamp on/off (although when turned on, the timestamps are not handled...)
• t -- Transmit standard (11bit) CAN frame
• T -- Transmit extended (29bit) CAN frame
• r -- Transmit RTR standard (11bit) CAN frame
• R -- Transmit RTR extended (29bit) CAN frame

Hardware I am currently using for the module:

• Seeed CAN-BUS Shield (http://wiki.seeed.cc/CAN-BUS_Shield_V1.2/)
• Arduino flashed with firmware implementing CAN232 protocol (https://github.com/latonita/arduino-canbus-monitor)

Screenshot from the web interface:

All feedback are welcome!