How to set the payload length and the width of address to communicate with 24L01+

RE: How to set the payload length and the width of address to communicate with 24L01+

Jon Gunnar — Wed, 20 Nov 2013 08:50:51 GMT

Hi,

The nRF2402 doesn't know what part is the address and what part is the payload. It is just a transmitter, so it doesn't have to distinguish between address and payload like the receiver does. It only need to know how many bits you have clocked in, and it does so by counting clock pulses.

Best regards, Jon Gunnar

RE: How to set the payload length and the width of address to communicate with 24L01+

Alice — Tue, 12 Nov 2013 07:00:55 GMT

Hi Jon,

Thank you for your answer. Since there therer is no configuration settings for address width and payload length and the address width is 8 to 40 bits.I have known in ShockBurst™ mode payload size is 256 bits minus the following: (Address: 8 to 40 bits. + CRC 8 or 16 bits).So when I set CE high and clock in the packet (address first then payload) before pulling CE low,how does the 2402 know how long is the address width and how long is the payload length?

For example,I set CE high after configuration and I load the 14 bytes data:0x12,0x34,0xaa,0xbb,0x52,0x68,0x89,0x65,0x97,0x36,0x45,0x88,0x95,0x12,0x36 How does the 2402 know what is the address and what is the payload?

BR Alice

RE: How to set the payload length and the width of address to communicate with 24L01+

Jon Gunnar — Mon, 11 Nov 2013 21:22:26 GMT

Hi Alice,

The nRF2402 has no configuration settings for address width and payload length.

You have probably seen that it has a very limited configuration word (page 15 in the product specification) where you must enable ShockBurst mode, select CRC mode and length, enable preamble and configure the right RF channel in order to be shockburst compatible. To load a packet for transmission you'll have to set CS low, wait at least 50ns, set CE high and clock in the packet (address first then payload) before pulling CE low to initiate the transmission. So, basically you clock in the address and payload for every transmission, and nRF2402 just wraps preamble and CRC around whatever you clock into it.

To receive this packet with a nRF24L01+ you must disable the enhanced shockburst features and run only plain shockburst.

Best regards, Jon Gunnar