2021-05-03, 07:39 AM
Most RS485-CAN-HATs have an 120 ohm Restistor between H And L soldered. Remove this with an sharp Knife or your fingernail... you can check this an Multimeter. But without powering the HAT! It should read something in the K-Ohms after removal.
On an correct Bus, like your Bus on the Boat now (also powerless, not active) the Multimeter should read 60 Ohm - with Terminatorresistors at both End from the Busline.
Good Luck
Holger
On an correct Bus, like your Bus on the Boat now (also powerless, not active) the Multimeter should read 60 Ohm - with Terminatorresistors at both End from the Busline.
Good Luck
Holger