I need to create a sensor network, with a central node receiving data from +10 different nodes, each one +20meters from the central node. So basically I need to create a star configuration, with a central node in the middle (a pcb with an raspberry pi) and than a big stub(around +20m) for each sensor node. I really don't know what protocol use: CAN, I2C or RS485.
My biggest problem is how to implement this kind of solution, cause for big stubs, there is a huge mismatch in the bus, so the signal is bad.
This article is amazing, show a lot of different configurations and the importance of terminator resistors for impedance matching. But I really need to implement a solution like Figure 12 or Figure 13, with stubs w/ +20meters.
This article explore the I2C solutions with P82B96 and PCA9615 transceivers, however, I still have the problem about star configuration and big stubs.
Best regards and sorry for my english.