Rev. 0.1 12/09
Copyright © 2009 by Silicon Laboratories
RF-to-USB-RD
R F - t o - U S B - R D
R F
T O
U S B R
E F E R E N C E
D
E S I G N
U
S E R
’
S
G
U I D E
1. Kit Contents
The RF to USB Reference Design contains the following items:
EZRadioPRO
®
F912/4431 Sensor Node
EZRadioPRO
®
F342/4431 Dongle
AAA Battery
2. Introduction
The purpose of this reference design is to demonstrate a very low-power, wireless USB system. The system
consists of two components: a wireless Sensor Node and a USB Dongle. The Sensor Node uses a Silicon Labs
C8051F912 MCU and a Silicon Labs Si4431 radio. The Dongle uses a Silicon Labs C8051F342 MCU and a Silicon
Labs Si4431 radio.
The reference design includes two demo applications which implement some typical usage scenarios. The RF to
USB Network Demo shows how the Sensor Node can be used as a wireless sensor, periodically transmitting
remote sensor data back to the host PC. The RF to USB UART Demo shows how the Sensor Node can be used as
a wireless link, shuttling data between two systems.
The wireless Sensor Node and the USB Dongle are small, simple designs and easy to implement, enabling them to
be inexpensively and quickly added to any system that requires wireless capability. There are very few components
required other than the MCU and radio, and typically expensive components such as a wired antenna and external
voltage regulator are not required.
The wireless Sensor Node operates at 915 MHz and is powered by a single AAA battery and uses the on-chip dc-
dc converter of the C8051F912 to provide power for the EZRadioPRO
®
radio and the other components. When the
wireless Sensor Node is not transmitting or receiving data, it can remain in a low-power state where it only
consumes 50 nA. The power efficiency of the Sensor Node allows it to operate on a single cell battery for an
extended period of time. The estimated battery life is seven years, limited primarily by the self-discharge of the
battery.
Figure 1. System Diagram
Network
Dongle
App
UART
Dongle
App
HID
Bootloader
UART
Demo
GUI
Network
Demo
GUI
App
Firmware
Image
Network
Node
App
UART
Node
App
EZRadioPRO
EZRadioPRO
Node
Dongle
PC
USB
Downloaded from
