Expansion Port PinOuts

toga94m · Post by **toga94m** » Sun Jul 26, 2015 9:10 pm

Ohhhhhhhhhhhhhhhh... interesting. I wouldn't have expected it would know the difference between "no bus" and "inactive bus". Let me try a few more things...

toga94m · Post by **toga94m** » Mon Jul 27, 2015 1:13 am

Still no go. I've got a broadcasting CANbus sensor hooked up to a USB diagnostic CAN interface on another computer, and have jumpered RCP CANx wires (CANH and CANL) onto the existing/running/communicating bus, then powered up the RCP, and the scripting log window still reports CAN controller reset fail. mode=0

I also noticed that there's no difference in error message if I have the CAN bus enabled or disabled on the CAN screen of the app... I'd think that disabling the CAN system would give different error messages.

The USB diagnostic interface is receiving messages at 500kBaud, CANID is 1592 although it's broadcasting on two IDs all the time, at a 10Hz rate. RCP and the sensor are both running from the same 12.6VDC power supply, so commons are common. If I unplug everything I can see 119.7 ohms between my two wires coming from the CANx module RJ45 so I know I've got the right two pins there. Tried swapping CANH and CANL with no effect.

I'll add some more test wires tomorrow and sniff out what the RCP is telling the CANx module via SPI...

toga94m · Post by **toga94m** » Tue Jul 28, 2015 1:07 am

Long story somewhat shorter... I scoped the SPI interface and found the CS* line (chip select) wasn't being driven. Brent suspected a broken solder joint between connector and main board. That looked okay, but then I stared into the RJ45 and saw this... one dental tool later, the pin is in line with the other 7, and I have a MK1 that can read CAN broadcast data!

Tomorrow I modify the MegaSquirt to enable CAN broadcast, and I'll hook them together and have a single tablet dashboard/logger with all the data I want. Then I'll want to add more sensors....

toga94m · Post by **toga94m** » Tue Jul 28, 2015 1:17 am

Another quick photo showing the CAN viewer that came with the sensor I lifted from work (dead project, good tool) and matching data on a dial on RCP dashboard.