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Version 1.3r 4/9/2012
7
RN -17 4-DS
Figure 3. Jumper Settings for Powering the Evaluation Board
Low-Voltage Mode
High-Voltage Mode (Default)
External Power Mode
•
Low-Voltage Mode (Battery Boost Enabled)
—When the board is configured in low-voltage mode, it MUST be
powered by 2.0 - 3.3 V DC power ONLY on the power connector (J7) or on the RS-232 header (J3). In low-power
mode, the battery boost circuit is enabled, which allows the input voltage to drop down to 2.0 V DC.
NOTE:
Applying a voltage greater than 3.7 V DC when the board is configured in low-voltage mode will
permanently damage the RN-171 module on the board, causing it to malfunction.
•
High-Voltage Mode (Battery Boost Disabled)
—Default. When shipped, the board is set up to use this mode.
When configured in high-voltage mode (4-16V DC), you must apply power on the power connector (J7) or on the
RS-232 header (J3). The battery boost circuit is disabled in this mode.
•
External Power Mode
—This mode is used when powering the module from a regulated 3.3-V power supply to the
UART header (J8) or if you are using the RN-G2ISP to power the module. In this mode, the module cannot be
powered from the RS-232 header (J8) or the power connector (J7).
Configuring the Module for Low-Current Consumption
The RN-171 module draws only 4 uA when it is in a sleep state. To achieve this low current consumption:
•
GPIO pins 4, 5, 6, 7, and 8 must be pulled to ground using the pull up/down jumper (J2).
•
You should remove the RS-232 chip from the board or pull RTS and CTS to GND on the UART header (J8)
(optional).
NOTE:
If the RS-232 chip is installed, the current consumption will be around 88 uA when the 10-pin serial cable is
disconnected and 160 uA when the cable is connected to the RS-232 device.
Sensor Interfaces
The sensor inputs must not exceed 1.2 V. The ADC saturates at 400 mV. Roving Networks recommends that you use the
sensor power output to drive any analog devices that are attached to the sensor pins.
NOTE:
Sensor pins 2 and 3 have a resistor network in front of sensors 4 and 5, respectively, so these pins can be
driven with up to 5 V DC.
Ad Hoc & Restoring Factory Settings
Jumper J6 on the jumper header is connected to GPIO9. When this jumper is in place, the module powers up in ad hoc
mode. If the jumper is then toggled 5 times, the module is restored to the initial factory default configuration. This setting is
useful for cases in which the module is misconfigured and is no longer responding.
