WiFly GSX
WiFlyGSX-um.pdf 11/11/2009
www.rovingnetworks.com
Phone 408-395-6539
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2
Hardware Interface
See the RN-131 or RN-134 data sheets on the Roving Networks website for technical specifications
and layout information of these modules.
2.1
Power
There are two options for powering the RN-131G module directly.
DC SUPPLY: Apply 3.3 VDC power to VBATT (pin 20), and V3.3IN (pin 21). Tie 3.3VREG-IN (pin 18)
to GROUND. 3.3V-REG-OUT (Pin 17) leave floating.
BATTERY: Apply battery = 2.0 to 3.3VDC to VBATT (pin 20). V3.3IN pin 21 = floating.
Tie pin 17 to pin 18. (This enables the on board battery boost 3.3V switcher).
There is a built in voltage brownout monitor which will shut down the chip when the voltage drops
below 2.0 VDC.
Warning: Do NOT exceed the voltage ratings on the 3.3V pins, damage to the module will result.
Notes:
#1: The Sensor inputs SENS0-7 are extremely sensitive to over voltage. Under no conditions
should these pins be driven above 1.2VDC. Placing any voltage above this will permanently
damage the radio module and render it useless.
#2: Placing 5VDC or any voltage above 3.3Vdc into the VDD pins of the module will
permanently damage the radio module.
#3: Placing 3.3Vdc into the PIO’s while they are set as outputs will permanently damage the
module. The failure mode is a short across GND and VCC.
2.2
Reset
Reset is active LOW and is optional/does not need to be connected. The reset pin is 3.3V tolerant
and has an internal pull up of 100K to the VBATT.
2.3
UART
Connect a common ground when using the external TX, RX inputs.
For a 3 wire DB-9 interface (connect tx, rx, gnd only)
Factory default is hardware flow control disabled, CTS and RTS are not required.
When using a 5.0 VDC Input, PIO’s and UART input pins require a resistor divider. A suggestion is
10K in series with 20k to ground. PIO’s are 0-3.3 VDC not 5.0 VDC tolerant.
