Revision 1.0
Page 9 of 17
nRFready Microphone User Guide
All the communication in the system is digital and packet-based, which means that data between the units
is exchanged as discrete packets of information. The raw audio throughput of each microphone is
32 kHz x 16bit = 512 kbps, while the on-air data rate of the packet-based communication is 4 Mbps. This
additional bandwidth allows the system to cope with tough interference and yet maintain un-interrupted
audio between microphones and receiver.
The nRF2460 wireless audio streamer used in the system, monitors and handles all real-time tasks, such
as adaptive frequency hopping, retransmission of lost audio packets, acknowledgements, synchronization,
audio buffers and link quality. The receiver board has two nRF2460s that are placed on the same PCB,
and the nRF2460 has a built-in synchronization mechanism that allows the two nRF2460s to operate in
close proximity, yet without interfering with each other. In addition the two microphones use non-
overlapping hopping tables that are spread across the entire 2.4 GHz band to avoid co-channel
interference.
The nRF2460 has configurable latency. Using the high latency setting provides the most robust audio link
due to the increased time to retransmit. The latency is configurable from 20 to 26 ms, and in this system
the highest audio setting is used.
This design supports two microphones to be used at any time. Just insert batteries, turn on the
microphones, connect the receiver to the appropriate input, and start singing or talking.