Why?
CAN bus is a common communication method that you can commonly used in automotive and robotics field for the simplicity of the connection. However, in order to communicate through CAN, we need a CAN device/module. In this post, we discuss CANable for its offer on easy feature, from USB to CAN.
Story: I have a single board computer running Linux with no CAN feature. And I want it has the ability to read or write CAN messages for other device. The application I want is to read and report information through CAN, it has no mission to control any critical situation. The SBC comes with many USB/Serial port and GPIO however. My options are to get some CAN modules that may cost a few dollars and do my own wiring with the GPIO to give the computer CAN feature; OR, to use a CAN <-> USB adapter to make life easier. Due to the constraint of time and simplicity preference, I chose the later option. CANable is the number 1 result that popped up on my search and I just went for it after seeing many good reviews.
Cost
With some research, one can find a wide range of CAN devices between $10 – $1000. To my experience, the differences come with reliability. One example is for the CANable device itself ($60), some credit and disclaimer to note from the website.
The CANable Pro is a low-cost open-source hardware tool. While I have full confidence that the CANable Pro will meet your needs, please do not use the CANable Pro in any mission-critical or life-threatening situations.
To be honest, $60 is not exactly cheap, but it’s much cheaper than a $200, $400 devices that I had used before and probably cannot afford myself for robotics hobby. But I see many positive reviews about CANable from people using it in the past. So I’m rooting much for this device here.
The pro version is doubled the price of the regular version actually, so you can go with cheaper one as well. In fact, many great reviews are for the regular device. They only launch the Pro version recently.
Shipping
Despite $60 worth, there is no free shipping option from the Profusion Labs. First-class is $5ish and Priority is $9.99. But they shipped fast, I got tracking minutes after order and the device comes exactly 2 days later with Priority shipping.
Built
It is small in compact form, and I feel the quality of the built is nice. It has 4 mounting holes available. 120ohm terminal built in with boot button for firmware updating. Some extra features to help protecting your pc hardware which the regular version do not have.
There are 2 LED lights, the Green one should show up when you first powered it up. When transmitting (TX) message, the green light flashes. When receiving (RX) message, the blue light flashes.
Connector: it has a Micro USB B and no cable. So you would need your own cable to connect to your PC. This is actually something that I wish that they have other different built to offer, such as a regular USB Male port attached directly into the board and it can be plug and unplugged like a USB stick. Because I want to attach this permanently into a single-board computer.
Setting Up
The procedure is pretty much straight forward at the “Getting Started” section on https://canable.io/ website to set up the CAN interface with slcan. I use it on Linux, so the commands work out with no problem for me.
But I ended up updating the module with candlelight firmware that they mentioned, just to make it more convenient to set up. The module did not come with candlelight, so we have to do it ourselves per the instructions on the website. Again, it’s pretty easy on Linux.
To update firmware on the Pro version, you need first to unplug the device if it’s plugged. Then hold the boot” button and plug it back and release. At boot mode, no LED light would flash. You should download the *bin file for Candlelight firmware, then run the command to update. After update firmware, unplug and plug the device back.
(There is also the web updating option at the UPDATER link on the website, but I did not try it out)
Scratch Robotics 