The RF_SETUP register is used to configure the radio’s data rate and power output.
This table is copied from the nRF24L01 product specification (page 54).
|Reserved||7:5||000||R/W||Only ‘000’ allowed|
|PLL_LOCK||4||0||R/W||Force PLL lock signal. Only used in test|
|RF_DR||3||1||R/W||Air Data Rate
‘0’ – 1Mbps
‘1’ – 2Mbps
|RF_PWR||2:1||11||R/W||Set RF output power in TX mode
’00’ – -18dBm
’01’ – -12dBm
’10’ – -6dBm
’11’ – 0dBm
|LNA_HCURR||0||1||R/W||Setup LNA gain|
According to Bell (nRF24L01 tutorial 0), changing the values of PLL_LOCK and LNA_HCURR “could cause stuff to go weird.” The LNA gain controls the nRF24L01’s Low Noise Amplifier, which reduces the radio’s current consumption at the cost of some sensitivity (see nRF24L01 Product Specification, page 23).
For the software driver, the data rate and output power can be set by the application.
Using the 1 Mbps data rate improves the radio sensitivity and decreases its power consumption, but obviously transmits data half as fast as the 2 Mbps rate.
See the hardware section of this report for a discussion on power output.