I currently have 3 XBEE S1. I want to create a star-network with the following properties:

1 of the XBEE S1 is connected to a Raspberry Pi and I want it to be the Coordinator.
2 of the XBEE S1 are connected to Arduinos and I want them to be the End Devices.

The Coordinator is going to receive data from the two End Devices.

I only manage to send information from one of the End Devices to the Coordinator. It works properly.

I don’t know if this type of network is possible for XBEE S1. Should I buy XBEE S2?

If it’s possible, how do the configuration parameters of the XBEE look like?

I don’t know either if I have to use API or AT mode. In any case, do I have to add something special to the script of the Arduinos?

Sorry, my English is not really good.

Thanks a lot!!!