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Old 03-08-2011, 04:30 AM   #4446 (permalink)
DJBecker
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Quote:
Originally Posted by vwdevotee View Post
I was looking at the Rev D drawings, and it looks like all of the pins have been taken up by current features. With absolutely no real basis for it, I was looking at DACs and it looks like this one <http://www.rohm.com/products/databook/general/pdf/bh2220fvm-e.pdf> would be a good fit. It looks like it could run the three gauges I want to use (Tach as a big ammeter, Fuel as SOC, and temp as, umm, temp) with some op-amps. Am I reading the schematic wrong, or has it changed so that some pins would be available? Or would it just be simpler for something like this to switch over to an XMega since those can be had with up to 16 ADCs and 4 DACs onboard? Would most if not all the code port over from the Atmega168 to an Xmega MCU? Thanks in advance.
I believe that the best way to expand is to hook up a MCP2515 CAN bus controller on the SPI port. It only takes one free pin as a chip select, and gives the most flexibility.

Once you have a CAN network, many different options are available without changing the motor controller. It's easy to add features such as custom gauges, and even cruise control. We previously were using a ScanGauge for reporting, and have now upgraded to an Android phone for reporting. The latter is via a OBD2 bluetooth module on the CAN bus and the "Torque" app.

Our long term plan is to put a controller in the dash to drive the instrument cluster gauges based on the values read from the motor controller, but that's a lower priority since it we already have the info on the Android display, complete with data logging.

Last edited by DJBecker; 03-08-2011 at 04:39 AM..
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