The python crazyradio lib can be found in the Crazyradio git repos https://github.com/bitcraze/crazyradio-firmware/blob/master/lib/crazyradio.py. It is a single file that implements the low level Crazyradio dongle functionalities.

The Crazyradio is configured in PTX mode which means that it will start all comunication. If a device in PRX mode is on the same address, channel and datarate, the device will send back an ack packet that may contains data.

   Crazyradio    Device
      _             _
      |             |
      |  Packet     |
      |------------>|
      |        Ack  |
      |<------------|
      |             |

Ths is an example on how to use the lib:

import crazyradio
 
cr = crazyradio.Crazyradio()
cr.set_channel(90)
cr.set_data_rate(cr.DR_2MPS)
 
res = cr.send_packet([0xff, ])
print res.ack                   # At true if an ack has been received
print res.data                  # The ack payload data

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