RN-131G
rn-131-um.pdf 5/14/2009
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Upon the start of transmission of the first UDP data packet this timer will count down.
set sys autosleep <value>
UDP mode: sets the auto-sleep timer. 0 disables
the timer is decremented every 10 milliseconds. Because the timer is asynchronous, the
actual value can vary by 10ms. Using a minimum value of 2 is recommended to ensure
that the UDP packet gets transmitted. For larger packets the value should be increased.
In TCP-Client mode, the auto-conn timer is used as a connect out timer. If set, the device will
automatically attempt a connection when the timer expires.
set sys autoconn <secs>
In TCP-Client AND TCP-Server mode, there is also a disconnect timer.
set comm idle <secs>
sets the idle disconnect timer. This causes a disconnect if no transmit
or
receive data is seen.
8.3
Wake on Sensor INPUTs
There are 4 inputs available to wake the module from sleep, SENS0-3..
To enable 1 of these inputs, use: s
et sys trigger <value>.
0 disables. This is a bit-
mapped setting. To wake on sensor pin 2, you would use
set sys trig 4
, for example.
Unlike the RN-111b, The
SENSE
inputs do NOT have a resistor divider to allows pins to
tolerate 3V logic. So a minimum of 24K in series with 10K to ground as a divider network
from the UART RX or CTS pin should be used.
WARNING: Under no conditions should the voltage on any SENS0-7 input exceed
1.2VDC. Permanent damage to the module will result.
The SENS0-3 inputs have a small current source that is activated in sleep mode. This source
is approximately 100nA, and will cause the input to float up to about 1.2VDC. IF SENSE1 for
example, is enabled, pulling the SENS1 pin to GROUND will wake the device. An open drain
FET is a good device to tie to the pin. The threshold is about 500mV. Additional pullup to
1.2VDC may need be used if the circuit has an impedance (due to leakage current) of less
than 5Mohms ( 500mv / 100nA ). SENS1-4 pins that are not used should be left
unconnected.
8.4
Wake on UART
When the module is in Sleep mode, the UART itself is disabled. However, wake on UART can
be accomplished by connecting the SENS1 pin to the RX data pin. (using appropriate divider
resistors mentioned above) The SuRFboard for example, has built in resistor dividers to
allow wake from RXD or CTS pins.
To enable wake on RXD , use s
et sys trig 1.
It should be noted that the first (or possibly multiple) byte sent into the module will likely be
lost, so the designer should take care to send a preamble byte to wake up the module before
sending valid data bytes. A better way to do this is to use the CTS input to wake the
module, and wait until it is ready to accept data. To enable this, use
set sys trig 2.
