Pin Descriptions:

Pin nr.	Name	Direction	Default	description
pin 1	vcc
pin 2	Dout	Output	Output	UART Data Out
pin 3	DIN / CONFIG	Input	Input	UART Data In
pin 4	DIO12	Either	Disabled	Digital I/O 12
pin 5	RESET	Input
pin 6	PWM0 / RSSI / DIO10	Either	Output	PWM Output 0 / RX Signal Strength Indicator / Digital I/O 10
pin 7	PWM1 / DIO11	Either	Disabled	PWM Output 1 / Digital I/O 11
pin 8	[reserved]			Do not connect
pin 9	/DTR / SLEEP_RQ/ DIO8	Either	Disabled	Pin Sleep Control Line or Digital I/O 8
pin 10	GND			Ground
pin 11	DIO4	Either	Disabled	Digital I/O 4
pin 12	/CTS / DIO7	Either	Output	Output Clear-to-Send Flow Control or Digital I/O 7
pin 13	ON /SLEEP / DIO9	Output	Output	Module Status Indicator or Digital I/O 9
pin 14	VREF			Feature not supported on this device. Used on other XBee devices for analog voltage reference.
pin 15	Associate / DIO5	Either	Output	Associated Indicator, Digital I/O 5
pin 16	/RTS / DIO6	Either	Disabled	Input Request-to-Send Flow Control, Digital I/O 6
pin 17	AD3 / DIO3	Either	Disabled	Analog Input 3 or Digital I/O 3 Each reading is a 10-bit ADC value for a 2.5 V voltage reference.
pin 18	AD2 / DIO2	Either	Disabled	Analog Input 2 or Digital I/O 2 Each reading is a 10-bit ADC value for a 2.5 V voltage reference.
pin 19	AD1 / DIO1	Either	Disabled	Analog Input 1 or Digital I/O 1 Each reading is a 10-bit ADC value for a 2.5 V voltage reference.
pin 20	AD0 / DIO0	Either	Input	Analog Input 0, Digital I/O 0 Each reading is a 10-bit ADC value for a 2.5 V voltage reference.

The XBee Cellular Modem has 4 ADC inputs available to the user. These channels allow measurement of a voltage on the pin. The voltage measurement is represented and returned as a 12-bit value, which is a number between 0 and 4095, where 0 represents 0 V and 4095 represents 2.5 V.