Quote:
Originally Posted by sawickm
Hey Paul,
If you want to add “CANbus” to the Atmega ReVolt Cougar PCB than check this out: CAN-SPI Adapter
You should just be able to interface it into the “Cougar” Rev.C SPI port.
If that would work ??? “CANbus” could be added on-board for next version of the “Cougar” Rev.E ???
-Mark |
There are several CAN controller boards advertised on the web. None are readily available in the U.S., and they are expensive for what they are. They all use the MCP2515 chip I talked about in post 4157
http://ecomodder.com/forum/showthrea...tml#post209940
As I mentioned in that post, the main chip is under $2 in single unit quantities. They *might* be able to justify their US$50 price if they have jumper options for an isolating transceiver and on-board voltage conversion. But they are just the MCP2515 and a basic transceiver.
(The MCP2515 is pretty much the only external CAN controller available. The few others are out of production, so you can pretty much expect that's the chip everyone is using. And it's available in a standard DIP package so it's easy to do a DIY build project.)
All of the boards require more signals than the Cougar brings out to its header. The Cougar doesn't have a SPI chip select there, and this chip works best with an interrupt line.
In my implementation I clock the chip from a timer output run at 8MHz, so that's a third additional connection, although with the Cougar you might prefer to use a 16MHz crystal. Once you are doing that wiring, you might as well do the rest of the assembly on a protoboard.
The challenge, as always, is the software to make it work. I have a pretty good first pass that should be close to working with the Cougar if someone wants to work on the testing with me. Note that you can only test CAN if you already have a working network, as it requires at least one other active node to set the acknowledge bit.