The 171 module is a small form factor, ultra low power 802.11 b/g module. Measuring less than one square inch (27 x 18 x 3.1 mm), this module provides the flexibility of adjusting the transmit power and thereby the range. The RN-171 joins the Roving Networks family of Wi-Fi embedded modules.

The RN-171 is available in two variants, the RN-171 and the RN-171-UFL. The RN-171 contains a RF pad for integrating your own antenna. This gives customers the flexibility to design their own antenna system for the RN-171. The RN-171-UFL contains a U.FL connector for external antenna.

The RN-171 is a standalone complete TCP/IP wireless networking module. It is perfect for mobile wireless applications such as asset monitoring, sensors and portable battery powered devices. Thanks to the built in power management features, applications such as remote sensors can typically operate for more than a year on a pair of AA batteries.

The RN-171 incorporates 802.11 b/g radio, 32 bit SPARC processor, TCP/IP stack, real-time clock, crypto accelerator, power management unit, analog sensor interface and programmable GPIOs.

The module is pre-loaded with Roving Networks firmware that supports a range of networking protocols such as DHCP, DNS, ARP, ICMP, HTML client, TCP and UDP. In the simplest configuration, the hardware only requires four connections (PWR, TX, RX and GND) to create a wireless data connection.

The analog sensor inputs can be used to interface a variety of sensors such as temperature, motion, acceleration, etc. The ability to go into deep sleep mode and automatically scan and join a pre-set wireless network when awake makes the RN-171 suitable for roaming applications.

Developers will want to use the RN-174 evaluation board for prototyping and designing their WiFly systems. The RN-174 prototyping board is based on the RN-171 module and includes additional hardware such as power regulator, status LEDs, RS-232 interface and SPI slave interface for quick development and debugging.

The RN-171G-EVAL kit includes the RN-171 module mounted on a carrier board with status LEDs, power regulation, and a serial link to a PC.

The RN-171 is rated for industrial operating temperatures -45C to +85C.

Comparison between RN-171 and RN-131

• Ultra low power: 4uA sleep mode, 40mA RX, 180 mA TX ( at 10dBm)
  
• Firmware configurable transmit power: 0dBm to 10dBm
• Wide Operating temperature range: -45C to +85C
• Hardware interfaces: UART and SPI slave
  
• Host data rate up to 2Mbps for SPI slave and up to 921kbps TX, 500 kbps RX over UART
• Supports Adhoc and infrastructure networking modes
  
• 10 general purpose digital I/O
• 8 analog sensor inputs
• Real-time clock for time-stamping, auto-sleep, and auto-wakeup modes
• Accepts 3.3VDC regulated power supply
• Supports Battery boost circuit
  
• Configuration over UART or wireless interface (via Telnet) using simple ASCII commands
• Over the air firmware upgrade (FTP)
• Secure WiFi authentication WEP-128, WPA-PSK , WPA2-AES
• Built-in networking applications DHCP, DNS, ARP, ICMP, TCP, UDP, HTML client