The RF_CH register is used to set the channel on which the radio will broadcast.
This table is copied from the nRF24L01 product specification (page 54).
|Reserved||7||0||R/W||Only ‘0’ allowed|
|RF_CH||6:0||0000010||R/W||Sets the frequency channel nRF24L01 operates
Barclay, Craig, and Hoole give a table of channel ranges in the 2.4 GHz band:
|0 to 82||2400 to 2482||Legal, but noisy (conflicts with wireless LAN, Bluetooth, etc.)|
|83 to 99||2483 to 2499||Not legal for mobile|
|100||2500||Licensed in BC to Inukshuk Wireless|
|101 to 119||2501 to 2519||Legal|
|120 to 125||2520 to 2525||National and regional systems (Department of Defence, Telus)|
Channels from 101 to 119 are preferred, as they are legal to use and have relatively low traffic. The software driver sets the radio channel to channel 112 by default.
When the data rate is set to 2 Mbps, the radio uses two adjacent channels, so if students are using different channels to avoid interference they should be different by more than 2 MHz (e.g. 108, 110, 112, etc.).