Throughput on nRF51822 USB dongle

Question

Does anyone have any solid numbers on the maximum throughput achievable on
the nRF51822 USB dongle that comes with the nRF51822 Eval Kit? 
 Application - OTA protocol Gazell, three remotes transmitting 108 (data) bytes at each 600us timeslot.
Resultant data rate - 180KBytes/sec (+ protocol overhead). 
 Can the USB dongle (and driver) handle this rate? 
 ~GeoD

Håkon Alseth · Accepted Answer

Hi, 
 Gazell for nRF51 can only handle 1 packet every 2 x timeslot.
Given the lowest timeslot for 2Mbit on-air data rate, you will see a maximum throughput of:
1000/1.2 * 32 byte * 8 = 213.3 kBit/s 
 Getting through 180 kByte/s (1.44 Mbit) will be very hard in general, as overhead and startup time will have a great impact. You may reach speeds of around 1 Mbit/s if no ACKing is used, and no RF protocol is used (ie: example based upon radio_example in the SDK) 
 Regarding the UART-USB bridge on the SEGGER, we've tested 460k baud w/flow control and did not see any corruption. 
 Best regards
Håkon

Throughput on nRF51822 USB dongle

Top Replies