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transmission speed

In tihs video, and others this guy has done, the transmission speed of the nRF24L01 2.4G module only achieves a speed of, at best, about 300 packets per second (where a packet is 7 bytes) and it drops fairly quickly to about 150 packets per second beyond about 200m. That's only about 8,400 bits per second, whereas the module is claimed to be able to operate at 250k bits per second. That's about 30 times faster than the actual measured performance, and that's at the slowest claimed speed. How come the results shown in this video are so poor? There doesn't seem to be anything in his code that would slow things down so dramatically, in fact the programs don't do much other than reads and writes to the RF24 modules. What has to happen for these modules to perform at the claimed speeds? Thanks, Ian

PS apologies but I couldn't figure out how to add a tag.

  • Hi,

    The 250kbps is only the on air bitrate. What transmitting over the air is including the address, preamble, overhead,CRC etc, not just the payload. In addition, I'm not sure if the code the tester used was just transmitting or it's including ACK ? Also the DUT didn't send the packet as fast as possible but has some delay between packet. If you send bigger payload size = 32bytes, you will be able to reduce the proportion of the overhead.

    Please be aware, the nRF24 requires the radio be disabled and re-enabled after every 4ms of transmitting. You may take this into account when you try to maximize transmission rate. By theory we can achieve around 190kbps actual rate with the 250kbps mode.

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