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I/O support
Example
An ADC value received is 0x01AE; to convert this into a voltage the hexadecimal value is first converted
to decimal (0x01AE = 430). Using the default AV reference of 1.25 V, apply the formula as follows:
430 / 1023 (1.25 V) = 525 mV
Monitor I/O lines
You can monitor pins you configure as digital input, digital output, or analog input and generate I/O
sample data. If you do not define inputs or outputs, no sample data is generated.
Typically, I/O samples are generated by configuring the device to sample I/O pins periodically (based
on a timer) or when a change is detected on one or more digital pins. These samples are always sent
over the air to the destination address specified with
You can also gather sample data using on-demand sampling, which allows you to interrogate the state
of the device's I/O pins by issuing an AT command. You can do this on either a local or remote
device via an AT command request.
The three methods to generate sample data are:
Periodic sample
n
Periodic sampling based on a timer
l
Samples are taken immediately upon wake (excluding pin sleep)
l
Sample data is sent to DH+DL destination address
l
Can be used with line passing
l
Requires API mode on receiver
l
Change detect
n
Samples are generated when the state of specified digital input pin(s) change
l
Sample data is sent to DH+DL destination address
l
Can be used with line passing
l
Requires API mode on receiver
l
On-demand sample
n
Immediately query the device's I/O lines
l
Can be issued locally in Command Mode
l
Can be issued locally or remotely in API mode
l
These methods are not mutually exclusive and you can use them in combination with each other.
I/O sample data format
AO determines the format of the incoming and outgoing sample data.
By default, AO is configured to be compatible with legacy devices and outputs a legacy data format
regardless of where the sample packet came from.
Legacy data format
Regardless of how I/O data is generated, the format of the sample data is always represented as a
series of bytes in the following format which is compatible with the S1 802.15.4 and S2C 802.15.4
devices:
Digi XBee3® 802.15.4 RF Module User Guide
(IR
command)
(IC
command)
(IS
command)
DH command and DL
command.
Monitor I/O lines
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