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.
Can I use CAN? Can I use I2C (with P82B96 boost voltage transceiver or PCA9615 differential buffer transceiver) or maybe an RS85 with MAX485 IC?
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.