I think I CAN, I think I CAN... Topic is solved

[Gregski]

and we got ourselves a dime a dozen regular US 120 volt (pronounced: "one ten") 15 amp power cord, perfect for some troubleshootin'

[Gregski]

Ok so send the command with microchip at 500ms and heartbeat at 30ms from canalyst. If you can connect microchip the last one since it is probably terminated. You can disconnect termination resistor for canalyst so this is your best bet in the middle.

When connecting can modules you need to keep the length of the y line as short as possible, 10cm at most. Better to just put incomming and outgoing lines into the canalyst terminals altogether...

so here is my setup for dual CAN Bus analyzers (I realize the CAN bus wires are better off twisted together, these are just laid out for demonstration purposes)

[Gregski]

alright so I got both CAN analyzers hooked up and running and sending commands (one each)

and I figured out how to filter on CAN ID on the CANalyst-II (the pink one) so I confirmed that the black Microchip one is indeed sending it's message every 500ms as it should

yet it's still NOT WORKING

does what I am sending look alright in the window below to you all?

[Gregski]

so at this point it is one of these things:

1. I suck and have no idea what i am doing or I am simply making some bonehead mistake (highly likely)
2. the retail CAN analyzers suck
3. the charger is simply broken

[Gregski]

the-beatings-will-continue-until-morale-improves.jpg (76.25 KiB) Viewed 8851 times

[Gregski]

it's time for...




[ wait for it ]

[Gregski]

and here is how you bake a SavvyCAN cake, first the dry ingredients (aka the hardware)

you start off with a Chevy Volt first gen onboard charger

then you add a scoop of Arduino Due

a pinch of a CAN BUS transceiver (this is because the Arduino Due board is CAN enabled or CAN ready but it does not have all the extra hardware on it, so it needs what is called a shield, an add on or an adapter if you will)

yes this thing is tiny

a laptop as before

and of course a regular car battery

[Gregski]

Arduino does not make a Due board with a built in CAN bus transceiver EVTV.me does and calls it a EVTVDUE MICROCONTROLLER so we sent them $100 large and now we could wait for it to arrive, or we can roll our own today

the little CAN Bus transceiver is connected to the Arduino Due board (aka the brain ie microcontroller) via four wires, it get's it's 3.3 volt power from the Due board in daisy chain fashion

black - negative / ground
red - positive 3.3 volts
yellow - transmit
green - receive

[Gregski]

alright, congratulations we are half way there to setting up our DIY SavvyCAN thingie

now comes the wet ingredients aka the Software

yes Mr. Collin Kidder gives us a program to run, but that program needs something called Generalized Electric Vehicle Reverse Engineering Tool (GV-RET) which needs to be somehow installed on the Arduino Due board in order to run/execute, and for that we need something called Arduino IDE (Integrated Development Environment) think Notepad on steroids

arduino.png (4.24 KiB) Viewed 8832 times

[Gregski]

after you install Arduino IDE and tether your Due board to your computer for the first time you might get prompted to install a board driver, just go on and do it

[Gregski]

Arduino calls programs "sketches" and when ever you launch the IDE it opens to a fresh new sketch, it wants you to start writing some code, just ignore that for now

we need to tell Arduino what little brain board we are connecting to it via a USB cable, in our case it is a native Arduino Due so we go to:

Tools\Board\Arduino ARM (32-bits) Boards\ and select Arduino Due (Native USB Port) don't even connect to the other Programming port even if programming

now that we told it what board we have now we have to tell it what COM port it is on, the number does not matter, it's what ever COM port your computer finds the board connected to (you may have to close Arduino IDE and relaunch it to get it to see the board on a certain Port)

[Gregski]

[Gregski]

a great write up on CAN bus with Arduino Due is on our very own Wiki, no need for me to reinvent the wheel, but here is a summary

to get pretty much any program to run in Arduino you need something called "Libraries" or as I like to call them ".h files"

1. there are many different ways to install something called "libraries" in Arduino. Libraries are nothing more than just small snippets of code written by people who already dealt with the stuff you are about to deal with, and they were kind enough to save their work and offer it up to you to use so that you don't have to reinvent the wheel (think of it this way a screwdriver in your toolbox is like a library, you don't go buy a new screwdriver every time you go to work on something, you just reach for an existing screwdriver in your toolbox) for example somebody already wrote the code to make a microphone listen, so when you want to write some program that requires a microphone to listen, you can write it from scratch or just download some library called microphone.h because that what suffix the Italians put on their library files ".h"

One way to install libraries is to use the Manage Libraries menu item under Tools cause Arduino comes with a bunch of libraries but they are NOT installed (this is dumb) so you have to install the library that you want/need

the libraries come in different versions and chasing the latest version may not always yield desirable results and you may want to try an older version and if that still doesn't work go a few more version back (ask me how I know)

In order to get the Arduino Due board to realize it can talk to CAN transceiver you need to install a library called due_can this is one of those libraries you install using the Library Manger described above

[Gregski]

we are back to square one for the fourth time? this time using SaavyCAN here we can see that I managed to successfully connect to the charger and am actually once again reading the CAN bus messages flying by

Fun Fact: CAN Bus is chatty, imagine a bunch of birds sitting on a telephone wire all singing, screaming, chirping at the same time, everyone is talking to everyone, everyone hears all the conversations, yup that's good ol' CAN bus for you

[Gregski]

so with everything hooked up from what I know so far the first thing you have to do in SaavyCAN is make a connection, and you do that via the Open Connection Window and then you simply add a new device the Arduino Due in my case by telling SaavyCAN what Port it is on

New Connection.jpg (29.24 KiB) Viewed 8788 times

and here's a better look at my capture of frames

[Gregski]

alright then it was off to the Frame Sender window and the SaavyCAN documentation

so here is a first super simple message to only enable the 12 volt aka low voltage charger

[Gregski]

and here are both messages being sent

and here both frames or messages what ever you wanna call them are captured, does this look right? cause it's still not working

[Gregski]

[Gregski]

and literally in the 11th hour I got it working but only by enabling both the low voltage and the high voltage chargers using the 0x03 bit and when I do so I can see amps on the high voltage orange wire going into the battery, it reads 3.5 amps which is approximately half of what I have it set to ie 8 amps, but that's because I am on only 120 volts AC

[Gregski]

Fun Fact: I tried sending the first command at 100ms, 200ms, all the way up to 500ms and they all work for me, so not sure why it has to be at 30ms

also 0x02 or enabling just the high voltage charger works as well, this begs the question is my low voltage side of this charger broken? when I connect a simple multimeter to it with the low voltage charger enabled I should see a higher voltage like 14 volts or something right? well mine showed 10.5 and dropping and it's at 8.4 right now, so time to quit, I learned a ton

[arber333]

Sorry for not being there for you, even i have to sleep sometime .
I managed to find out CAN bus is very finnicky when it comes to Y cable length. So really short extensions from out of the main line please.
Also dont twist the wires in different directions...just dont!
And the use of the termination resistor... oh dear! I spent a lot of moments like "what am i doing wrong?" and it worked just fine when i sorted out two 120ohm resiators on both ends of the long twisted wires. If you measure across CAN twisted pair resistance shouldnt be much more/less than 60ohm. If it is more, than you have another resistor active somewhere...

[EV_Builder]

If it is more, than you have another resistor active somewhere...

If it's less you mean , adding resistors lowers the total parallel measurement

[Gregski]

Sorry for not being there for you, even i have to sleep sometime .

Don't lie, heroes never sleep!

[Gregski]

Oh my goodness, it all works, I figured it out, and you will not believe what was the problem!!!

I was trying to charge an AGM deep cycle battery and not a "real" car battery. Who knew that won't work?

[arber333]

If it is more, than you have another resistor active somewhere...

If it's less you mean , adding resistors lowers the total parallel measurement

Right...