User's Manual

Roving Networks Wifly RN-111B User Guide Version 1.16
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2. Introduction
Scope
This Integration and Users Guide, along with the RN-111b module have been developed
to assist users in embedding Wifi technology into their serial, SPI, and sensor devices.
The goal is to make the implementation of embedded Wifi wireless networks as seamless
and easy as possible. This document will explain how to setup and establish
communications between the RN-111b and Wifi enabled networks for data applications.
2.1 Hardware Interface
There are 3 options to power the RN-111b.
1. Supply 3.6 to 16VDC power to VIN (pin 13). Tie VREG (pin 14) to VBATT(pin 15).
2. Apply 3.3VDC regulated power to VDD (pin 17).
3. Apply battery = 2.0 to 3.0VDc to VBATT (pin 15).
If VIN is powered, VREG will supply 3.3VDC output and can be used for other circuits,
with a current limitation of 50 ma.
Reset is active LOW, is optional and does not need to be connected. There is a built in
voltage monitor that will pull Reset LOW (open drain FET) if the input voltage drops
below 2.7VDC. If external reset is desired, use an OPEN DRAIN driver and do not drive
the Reset pin to any voltage > 1.0 Vdc.
Warning: Do NOT exceed the voltage ratings on the 3.3V pins, damage to the module
will result.
Important Notes:
#1: RESET input is a low voltage (1.2VDC ) input, with a 10K pullup and built in
power monitor circuits. If external reset is desired, use pull down (open drain
or collector) only.
#2: The Sensor inputs SENS1-7 are extremely sensitive to over voltage. Under
no conditions should these pins be pulled high above 1.2VDC. Placing any
voltage above this will permanently damage the radio module and render it
useless.
#3: Placing 5VDC or any voltage above 3.3Vdc into the VDD pins of the module
will permanently damage the radio module. Be sure to use the VIN = pin 13
power pin for any power supplied that is > 3.3VDC.
#4: Placing 3.3Vdc into the PIO’s while they are set as outputs will permanently
damage the radio modules. The failure mode is a short across GND and VCC.
Use a 10KΩ resistor in series or a 10KΩ pull up resistor for input and output
PIO’s respectively.
• Connect a common ground when using the external TX, RX inputs.
• For a 3 wire DB-9 interface (tx, rx, gnd only) connect/short CTS to RTS, Factory
default is hardware flow control disabled, CTS and RTS not connected.
• When using a 5.0Vdc Input, PIO’s require a 10K ohm series resistor. PIO’s are 0-
3.3Vdc not 5 volt tolerant.