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Topic: Building a CAN API for Arduino DUE (Read 138 times) previous topic - next topic

Palliser

Hi zabaat. I am very happy for your interest to contribute on the CAN shield development. At this very moment, even thou I have done successful tests with the TI SN65HVD234 transceivers, we don't know precisely if they are going to be the best and final choice. I hope to get soon a feedback from Atmel about their tests (they are building their own DIY pseudo CAN shield). I also expect to receive next week a couple of DUEs I ordered almost two months ago to do some networking tests. Regarding the sketch, as I mentioned before here, it should be available in github on the next days.  You could start ordering the parts and building your own shield to be prepared to run tests once the API is released to public. Finally your idea of the gateway is very good knowing the need to integrate CAN with other protocols. Just hold it until the time comes. Regards!

that_kid


Hi that_kid. I am sorry to know about your broken foot. Just take it easy. Even thou I have my shield working OK, I still looking for a better out-of-the-shelf board that fits better the design. I am also working on some eagle files to build, at some time, my own design. Remember that for the two transceiver we are going to need 8 pins of the Arduino DUE (CANRX0, CANTX0, CANEN0, CANRS0, CANRX1, CANTX1, CANEN1, CANRS1). For my tests, I didn't use the EN and RS pins. I just connected them to +3.3 and ground respectively.


Thanks Palliser, I was also thinking of building my own board as well.  I have some other parts I want to add for other functions from the DUE.  In the meantime I'll just get a small board that I can mount the transceivers to for testing.  The good thing about not being able to move around much is that I can think more about my designs.

zad80

Hi All,
I'm very excited about this project and I'm constantly watching this thread for news and source.
BTW what we did here http://arduino.cc/forum/index.php/topic,135403.msg1064848.html#msg1064848 may be very helpful for the project  Have a look.
I'm planning to use a debugger too with the arduino , but that is still a working in progress.
Happy new year at everyone
  Zad

Palliser

For those that already have in mind an automotive application for the Arduino Due and the almost ready for release CAN API, while it seems to be too early, I believe is timely for them to start seeking out as much information as possible of the CAN protocol of their vehicles and get familiar with it. For example, the specific type of CAN standard and some specifications like CAN identifiers, Bit rate, message type (default 11-bit identifier?), data format, range definition, etc... I must say, during some tests, often, I had to stop my test and spend a considerable amount of time searching for needed CAN info. Oh, I forgot: try to get an OBD-II male connector (plug) and where is the OBD-II connector located in your car (Most are located under the steering column).

Palliser

I wanted to show, briefly, how I started building my second DIY pseudo CAN shield. I decided to use two SN65HVD235 transceivers in order to compare them with the two SN65HVD234 I used in my first shield. For these 235s I also used a different SchmartBoard: The model 206-0004-01, and instead of keep it intact, I did cut it. Here a picture of the two 235s soldered in the SchmartBoard, with pin headers and a pinout.

***********WARNING: This pinout corresponds to the SN65HVD234 transceivers. Not the 235 ones**********

I wanted to present it here, for those that have not started yet their shield, as an example to be followed using the previous schematic I published in this post. Even thou 234 and 235 transceivers are very similar, differ in the pin 5. For the 234 this pin corresponds to EN (enable) for an ultralow-current (50-nA) sleep mode and for the 235 this pin 5 corresponds to AB that implements a bus listen-only loopback which allows baud rate synchronization.

Notice that this second CAN shield, more than a shield, will work as a side car (alone or inserted in a bread board) unlike the first one which is a true shield. I made it that way to avoid soldering work. I hope to be uploading more pictures of my progress with it.



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