Ok.
USB hasn't changed much since then, so those bug fixes are probably going to have to go in as well.
Using the CAN interface
(103 posts) (27 voices)-
becker
MemberI thought I would add something for the archives.
On the STM32F10x parts you cannot use the USB and CAN at the same time.
It's not a issue with overlapping pins. Remapping the CAN to different pins would fix that. The problem is that they share the same "SRAM buffer" memory. Or rather they *don't* share.
This seems to be fixed in the new STM32F2xx parts.
If you are going to use CAN, you can hook a transceiver board directly to the USB connector. You don't need to modify the board or the installed components. The series resistors and damping capacitors on the USB data lines (22 ohms and 47pf) will have negligible impact on the Tx and Rx signals. The pull-up bias on the D+ plus line will use a little bit of extra power, but won't stop communication. It is better to disable it in software, but even if you don't it's not a problem.
Posted 4 years ago # -
check out the olimex maple clone. It has CAN and USB.. They are using pins other than USB for TX/RX. Hopefully someone can help with a .zip of the files needed.
http://www.olimex.com/dev/DUINO/OLIMEXINO-STM32/OLIMEXINO-STM32-schematic.pdf
I jumped the gun and have a few of these coming, but I need CAN to work. Finally there is an arduinoish board with a CAN transciever built in!
Posted 4 years ago # -
becker
MemberThe reason they put the CAN transceiver on the CAN controller remapped pins is because there is no common CAN transceiver that can disable its CAN_RX output. And even with a software disable, there would be the risk of a USB device conflicting with the CAN transceiver output.
If you hook up a CAN transceiver board through the USB connector you don't have that problem.
I note that they did hook up the CAN transceiver's RS pin so that it can be put into low-power sleep mode. There are better transceiver choices if you especially concerned about minimum power use, but I doubt anyone using that board is expecting it to be really micro-power.
Posted 4 years ago # -
I see Makefile inside STM32 folder and link to http://code.google.com/p/arm-utilties not availbale.
Posted 4 years ago # -
becker
MemberThe CAN support isn't in the tar file.
http://code.google.com/p/obd2-instruments/source/browse/#svn%2Fobd2-instruments%2FSTM32
Posted 4 years ago # -
Hello again Everybody,
Unfortunately, time became a major project I was working on. So I wound up modifying the PE2116 board I already had by adding a MCP2515 CAN controller and a set of jumper selectable drivers (Had applications using the standard 2-wire '251 driver, but also needed a one wire driver CAN driver for GM and a fault tolerant driver for Tesla Motors) If anybody's interested I'll post it's Eagle files.
As it stands I still have the two Maple boards I ordered with nothing to use them on. I have a project coming up that will require accessing a uSD card. Might wind up using them for that, but I'm yet to see anybody on the Forum here using a Maple with a uSD card. (I'll have to do some digging)
Saw the link above to Olimex's board:
http://www.olimex.com/dev/DUINO/OLIMEXINO-STM32/OLIMEXINO-STM32_Rev.A-schematic.pdf
I might order a couple of those to play with.
Posted 3 years ago # -
mikep
MemberHere's a link to a project:
http://www.mikrocontroller.net/articles/BusAnalyzer
It's using CMSIS and ST Standard peripheral library. Also it's using the CAN pins remapped to PB8/PB9 (just like Olimexino).
Seems they circumvent the USB conflict by using a separate FT232.
It's using a different CAN Transceiver chip, but that should probably not matter.Looks like the code is an Eclipse project (has a make file).
If you're using Eclipse, might be possible to get this to work by using a separate USB/Serial converter to hook up to the USART used...
Note: I have not tried this out.
Hope that helps,
MikePosted 3 years ago #
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