I have am putting together multiple arduinos on a RS485 network (connected to Rx/Tx on the arduino and using Serial - connection via one of these https://www.ebay.co.uk/itm/272929871278) - RS485 because it is spread over quite a distance - total linear wiring approx 200m.
My question is: If I have Master, Slave1 and Slave2 on the bus, and the link is running at full speed in comms between Master and Slave1 - then what is the expected interrupt handler overhead on Slave2 in putting the incoming traffic into the ring buffer? (since as it is RS485 all devices not sending see all the traffic)
My "finger in the air" estimate is around 5%-15% at 256k baud and would scale fairly linearly with baud rate.
Does anyone have a definitive answer on this or can point to any profiling done on this?