Looking for a little collective knowledge from the crowd here.
I have a project which requires me to convert a CAN bus message to a 0-5v analog output to interface with a data logging system with no CAN interface.
Initially the application is for just 2 0-5v outputs, but 8 would probably be a longer term goal.
-The outputs would be 0-5v with a very low <20 ma current draw.
-CAN Bus is 1Mb, standard 11 bit ID’s
Thoughts? Available somewhere I haven’t found yet?
Let me know…
Thanks,
Find a suitable MCU with CAN and attach a dual DAC chip to it. There are lots of them, including some NXP ARM chips. Just attach more DACs when you need 8 outputs.
Leon
If you’re using an extra chip for the DAC I would recommend a PIC MCU since some 18FXXXX’s have CAN and they are cheap and easy to program (you could probably build a programmer yourself)
hope this helps a little!
Thanks for the replies so far, I spent some time researching an off the shelf solution and that’s not really going to work, so I’m going to have to look at building one myself.
Roicker, thanks for that tip! BTW your signature line is so true!
Keep those tips coming!
CAN originates in the vehicle world and a lot of information can be found on sites dealing with on-board diagnostics (search for OBD + CAN on e.g. google). Just as a suggestion if you are looking for ways to attach to a CAN.
There are a few popular CAN controllers (if your microcontroller doesn’t have one built in). The most popular is SJA1000, but it has a cumbersome parallel interface D0…D7, WR, RD, CS, … There’s MCP2515 which has SPI/Microwire, you’d be able to easily hook the latter up to e.g. a Arduino (if you fancy that).
The pca82c250 is the canonical physical interface chip, it connects your CAN controller (or microcontroller with built in CAN controller) to the physical CAN bus.
The datasheets will have schematics for the usual way to hook the chips up.
The MBED board has both CAN and a dual DAC (as well as Ethernet and many other peripherals).
You’d have to add an external op amp circuit to boost the 0-3.3V DAC output to 0-5V, as well as an external CAN transceiver chip.
It can be powered from 5V.
Many of the ARM Cortex-M3 development boards have CAN connectors with transceivers, though their DACs would probably still need external amplification.
I currently have these boards that we made for a hybrid vehicle project. PM for information. We act on a can message and can output 0-5 on two analog output channels.
Brayden