Pin Number	Pin Name	Nano Pin	Abbreviation	Function
1	Ground	GND	Ground	Connected to the Ground of the Nano
2	Vcc	3.3V	Power	Powers the module using 3.3V
3	CE	D9	Chip Enable	Used to enable SPI communication, defined in Radio in code
4	CSN	D10	Ship Select Not	This pin has to be kept high always, else it will disable the SPI, defined in Radio in code
5	SCK	D13	Serial Clock	Provides the clock pulse using which the SPI communication works
6	MOSI	D11	Master Out Slave In	Connected to MOSI pin of MCU, for the module to receive data from the MCU
7	MISO	D12	Master In Slave Out	Connected to MISO pin of MCU, for the module to send data from the MCU
8	IRQ	Empty	Interrupt	It is an active low pin and is used only if interrupt is required, not used

Connection Specs

Vin – Battery +
GND – Battery –
5V – Cable open
D13 – RF24/5
3V3 – RF24/2
A0 – R10K
A1 – R10K
D12 – RF24/7
D11 – RF24/6
D10 – RF24/4
D9 – RF24/3
R10K – GND
R10K – GND
R10K – Cable open
R10K – Cable open
GND – RF24/1

Start attaching the 9V battery into the project, and how it works with the nano and RF24. By tracking the voltage of the 9V battery, finding out the usage of the power.

0:00 – 7.99V

+9h – 7.4V

+19h – 7.09V