I want to setup a Raspberry Pi zero as a headless data collection and communicator. The way I want to do it is as follows:
Connect the sensors using USB or I2C or SPI. Once the data is communicated to the Pi, it transmits the data over Xbee to a PC.
To add more functionality I want to have a SSH running over the Xbee connections, so that I can start and stop, and possible change some python code over the xbee , using the PC(something that will be convenient during system upgrades).
Currently I have used established a shell through the serial port using a USB to TTL cable, and its worked. I have a pair of Xbee series 2 and I have set them up for communication (one is the Xbee coordinator AT, the other is just a Xbee AT).
I am assuming that the XBee in AT mode will behave just like a wired connection.
When I replace the USB/TTL wire with the modules I do not get access to the shell, its just a blank screen. To test further, Ive done a hot swap i.e starting the system first with USB/TTL wire, logging in and switching to Xbee, but no luck, the Xbee com screen is just blank.
Any idea where the error may be? or what different implementations of the systems can I use to accomplish my objectives?