I finally got to install the PDM in a vehicle, but has anyone had any issues @ 125kbps on BCAN, specifically on a 10th gen civic. intermittantly, every couple maybe 20-30 seconds, you hear a relay click in the dash, and some lights on the dash flick once, while the engine is idling or in motion. When i disconnected the PDM the issue is gone. Is there a termination in the PDM causing an issue? the bus is 125kbps and all extended frames. the PDM has no broadcasting setup so it only listens on 0x7005 (not used on the bus) for CAN inputs. There is no inputs/outputs connected on the PDM as of yet.
Is it also possible the 125kbps is not properly adjusted to the clock of the PDM giving an offset which is affecting the bus?
What do the can Tec and rec need to be at? 0?
hi George, possible bug, it turned out not to be an issue with the PDM, per say. But the PDM did affect the bus in this scenario. My CAN activity detection board which gives signal to the IGN line was glitching off/on once every 20-30 seconds due to an ISR issue in the code. While this was the root cause, it showed an issue of when the PDM boots or shutsdown (i can't tell which since the IGN line goes low and high in a fraction of a second), and interferes with the bus in some way I guess when the CAN controller shuts down (or boots) on the PDM. possible fix to prevent this would be either setting the CAN lines in firmware to high impedance or set listen only mode before boot/shutdown
are you sure it's 150kbps?? where did you see that? i've used arduino on it for last 2 years, i have read and written frames on the bus as well, including writing kwp2000 frames which activates some outputs of the BCM. the arduino has no issues being on the plug end of the pdm25 and the bus doesnt skip intermittantly like the pdm does every 20-30 seconds, thats why i dont think its a wiring issue. usually some bitrates are not **exactly** X depending what the peripheral clock is set to, that's why i asked
Do you have any CAN inspection hardware (CAN-USB connection and monitor software)? My first web search says the Honda BCAN uses 150kbs. So you must find the correct bus specs at first.
A wrong CAN setup will disturb the hole communication on the bus.
Hi Tony, adding a new device to the bus can cause issues to the bus stability even if that device is only receiving. Please ensure that the general rules of the CAN Bus are adhered to still (in this case, stub length). The PDM does not have any termination resistor inside.
Please can you check your CAN tec and rec values in the monitor tab, this will shed some more light on the issue.