Digi XBEE2 User Manual

Analog and digital IO lines IO sampling
XBee/XBee-PRO ZigBee RF Modules User Guide 104
 Periodic sampling
 Change detection sampling.
IO sample data is formatted as shown in the table below
The sampled data set will include 2 bytes of digital IO data only if one or more IO lines on the device are
configured as digital IO. If no pins are configured as digital IO, these 2 bytes will be omitted.
The digital IO data is only relevant if the same bit is enabled in the digital IO mask.
Analog samples are returned as 10-bit values. The analog reading is scaled such that 0x0000 represents 0V, and
0x3FF = 1.2V. (The analog inputs on the module cannot read more than 1.2V). Analog samples are returned in
order starting with AIN0 and finishing with AIN3, and the supply voltage. Only enabled analog input channels
return data.
Bytes Name Description
1
Sample Sets Number of sample sets in the packet. Always set to 1.
2
Digital Channel Mask Indicates which digital IO lines have sampling enabled. Each bit corresponds to one
digital IO line on the module.
bit 0 = AD0/DIO0
bit 1 = AD1/DIO1
bit 2 = AD2/DIO2
bit 3 = AD3/DIO3
bit 4 = DIO4
bit 5 = ASSOC/DIO5
bit 6 = RTS/DIO6
bit 7 = CTS/GPIO7
bit 8 = N/A
bit 9 = N/A
bit 10 = RSSI/DIO10
bit 11 = PWM/DIO11
bit 12 = CD/DIO12
For example, a digital channel mask of 0x002F means DIO0,1,2,3, and 5 are enabled as
digital IO.
1
Analog Channel Mask Indicates which lines have analog inputs enabled for sampling. Each bit in the analog
channel mask corresponds to one analog input channel.
bit 0 = AD0/DIO0
bit 1 = AD1/DIO1
bit 2 = AD2/DIO2
bit 3 = AD3/DIO3
bit 7 = Supply Voltage
Variable
Sampled Data Set A sample set consisting of 1 sample for each enabled ADC and/or DIO channel, which
has voltage inputs of 1143.75 and 342.1875mV.
If any digital IO lines are enabled, the first two bytes of the data set indicate the state of
all enabled digital IO. Only digital channels that are enabled in the Digital Channel Mask
bytes have any meaning in the sample set. If no digital IO are enabled on the device,
these 2 bytes will be omitted.
Following the digital IO data (if any), each enabled analog channel will return 2 bytes.
The data starts with AIN0 and continues sequentially for each enabled analog input
channel up to AIN3, and the supply voltage (if enabled) at the end.

Digi XBEE2 Specifications

General

Brand	Digi
Model	XBEE2
Category	Control Unit
Language	English