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CyFi™ Low-Power RF | Cypress Semiconductor

CyFi™ Low-Power RF

This product is Not Recommended For New Designs. Visit our Wireless Connectivity home page to check out our new wireless products.

CyFi (CYRF7936) is a 2.4 GHz ISM radio transceiver, capable of supporting data rates upto 1 Mbps. It features a 1-Mbps GFSK radio front-end, packet data buffering, packet framer, DSSS baseband controller, and RSSI.

CyFi allows implementation of mixed-rate systems in which different devices use different data rates. It also allows the implementation of dynamic data rate systems that use high data rates at shorter distances.

The CYRF7936 IC has a power management unit (PMU), which allows direct connection of the device to any battery voltage in the range 1.8 V to 3.6 V.

CyFi features the CyFi Star Network Protocol Stack that maximizes reliability and power-efficiency in a wireless networkby having up to 250 wireless nodes.

Key Features

  • Multi- Channel& Node Capacity: 98 discrete 1-MHz Channels supported, capacity of 250 nodes per hub
  • Data Rates: 125 kbps, 250 kbps and 1Mbps
  • Connectivity: 4 MHz SPI interface
  • Power Consumption: Operating current 21mA, sleep current 1uA, optimized for coin-cell, low impedance batteries and wall-powered devices
  • Package: Available in 40 QFN 6x6 mm


  • Wireless Sensor Networks
  • Wireless Actuator Control
  • Home Automation
  • White Goods
  • Commercial Building Automation
  • Automatic Meter Readers
  • Precision Agriculture
  • Remote Controls
  • Consumer Electronics
  • Personal Health and Fitness
  • Toys

Getting started with CyFi is extremely easy with the CY3271 and its expansion kits. These kits enable low-risk evaluation and advanced software application development for the CyFi solution. Read on to learn more about these kits or visit today and get your own PSoC FirstTouch Starter Kit with CyFi Low-Power RF to see how simple CyFi really is to integrate with your applications.

PSoC FirstTouch Starter Kit with CyFi Low-Power RF (CY3271)

CY3271 - PSoC FirstTouch Starter Kit with CyFi Low-Power RF
This intuitive starter kit allows you to evaluate the PSoC programmable system-on-chip and CyFi Low-Power RF in CapSense touch-sensing, proximity-sensing, temperature-sensing, and light-sensing applications. It includes a PC dongle with RF, an RF expansion card with power amplification for long-range applications, a multifunction expansion card, and two battery packs (2xAAA and CR2032). It also features the PSoC Designer IDE and Cypress's Sense and Control Dashboard Software.
This kit is also designed to support multiple expansion packs which are listed below.
View the Quick Start Guide for the CY3271 which showcases the different kit contents with a detailed description of what each component is and does.
View the User's Guide for the CY3271 for a detailed description of the different evaluations, solutions and demos this kit can do and the steps required to do them.

Expansion Packs for the CY3271

CY3271-EXP1 Environmental Sensing Kit

The CY3271-EXP1 is an expansion kit for the “CY3271 PSoC FirstTouch Starter Kit with CyFi Low-Power RF.” Included in the kit are two boards; the Weather Station Expansion Board (atmospheric pressure, humidity, temperature, and ambient light) and the Pigtail Thermistor Expansion Board. The Sense & Control Dashboard (SCD) from the CY3271 Kit lets users quickly setup and monitor a wired or wireless sensor network through an intuitive visual dashboard. Easily demonstrate features such as data logging, data aggregation, alarms, and sensor calibration for nearly any type of sensor.

CY3271-RFBOARD RF Expansion Kit

Expand your sensing capabilities with this kit. Included in the kit are 2 sets of AAA battery board and long range CyFi Low-Power RF board with sensing capabilities. Once programmed these boards are easy to detect and bind into your star network. Increase the nodes in your network and evaluate the networking capabilities of the product simultaneously improving real time environmental data sensing.

Cypress has training available to support you in a variety of formats including on-demand training over the Internet, hands-on workshops as well as live webinars.
Visit to find out more.

CyFi = PSoC CyFi Star Network Protocol CyFi Transceiver

PSoC Programmable System-on-Chip

PSoC devices combine dynamic, configurable analog and digital blocks and an 8-bit MCU on a single chip, enabling designers to build complete wireless embedded systems with fewer components and shorter design cycles. PSoC devices are the heart of a CyFi solution, running the application, the protocol and driving the CyFi transceiver. A CyFi solution utilizes any of the available PSoC devices or PSoC-based solutions (like CapSense, TrueTouch, EZ-Color, nvPSoC and more) as long as there is one available digital block and sufficient flash available to run the application. Flash requirements for CyFi solutions are extremely minimal compared to other embedded wireless solutions so you have a wide array of PSoC devices to choose from (as little as 8KB or 5KB required for a hub or node application, respectively).

The easiest way to get started is to develop your application in PSoC Designer using the largest PSoC device available. Once you have all of the discrete components integrated into your PSoC project that your application requires you can then better select the perfect PSoC device for your application. PSoC Designer makes this very simple to do by enabling you to change your target PSoC device within the software.

To learn more about the available PSoC devices and PSoC technology, please visit today.

CyFi Transceiver

The CyFi Transceiver is the muscle behind the CyFi solution. The PSoC device will run the protocol and the application while controlling the CyFi transceiver and ensure it best utilizes the many features of the transceiver to ensure reliable and power-efficient communications between the devices in your system.

The CyFi Transceiver features:

  • 2.4-GHz ISM Band Transceiver
  • Direct Sequence Spread Spectrum Modulation
  • 1 Mbps, 250 Kbps, and 125 Kbps data rates
  • 80 discrete, 1-MHz channels
  • Up to 4 dBm output power (on-chip)
  • Up to -97 dBm receive sensitivity
  • I/Os and control for off-chip power amplifiers

CyFi Star Network Protocol Stack

The CyFi Star Network Protocol Stack is the brain of a CyFi Solution. The protocol is run on the PSoC device and composes the algorithms and actions that the PSoC follows to drive the CyFi transceiver and maximize reliability and power-efficiency in a wireless system. This protocol stack is available in PSoC Designer as a simple, drag-and-drop user module. The protocol consists of a very simple API that enable you to quickly and easily implement an ultra-reliable and power-efficient solution in just minutes. The protocol has been designed with the following features:

  • Support for up-to 250 wireless nodes
  • Bidirectional communications (Node-to-Hub and Hub-to-Node)
  • Active link and power management
  • Power-optimization for coin-cell, low-impedance batteries and wall-powered devices
  • Simple network commissioning
Topology Network Capacity Stack Size Unique Features Development Kit Download
Star Network 250 nodes per hub Node: 4.5-7.5K
Hub: 8K

Asynchronous, bidirectional communication

Support for high-latency (battery-powered) and low-latency (wall-powered) nodes

Active Link Management for optimum reliability

Active Power Management for lowest system power

CY3271 Available Today in PSoC Designer

Enabling Worry-Free Wireless Networking

The CyFi Low-Power RF solution is a highly reliable, easy-to-use 2.4-GHz answer to a wide range of wireless embedded control challenges. It enables designers to create wireless systems without making compromises to overcome the typical risks of unreliable performance, complex implementation, and high power consumption. By combining Cypress's PSoC programmable system-on-chip, a sophisticated yet lightweight network protocol stack, and a Direct Sequence Spread Spectrum (DSSS) transceiver, the CyFi solution achieves levels of reliability, simplicity, and power-efficiency unmatched by other embedded wireless technologies. Download the CyFi Brochure today to learn more about this solution.

CyFi is a RELIABLE Solution.

CyFi is a SIMPLE Solution.

Design Effortlessly and Get to Market Faster

The CyFi solution offers a revolutionary level of simplicity to RF design. The CyFi Star Network Protocol stack is encapsulated into a PSoC Designer firmware user module with a versatile and complete API library literally enabling a drag-and-drop approach to RF design. Setting up the network, reliably transmitting, and receiving data, is a matter of a few simple API calls.

For all its sophistication in maximizing reliability and power-efficiency, the CyFi Star Network Protocol stack is surprisingly lightweight, occupying less than 6KB of code space for a node and less than 8KB for a hub. This frees up more room for building the complete embedded wireless system in a single PSoC device enabling reduced cost from BOM integration and lower flash-size requirements.

Ultimate Reliability

Reliable transmission is a key challenge in any wireless system. CyFi networks dynamically vary operating channel, data rate, and output power in real-time to maintain reliable communications in the presence of interference. This provides the designer with the benefits of using the 2.4-GHz ISM band (such as worldwide acceptance) without the reliability pitfalls commonly associated with other RF technologies in this congested band.

The combination of DSSS modulation, frequency agility, and a sophisticated link management algorithm gives CyFi Low-Power RF reliability that is simply unmatched by any other 2.4-GHz wireless technology.

Interference Immunity with DSSS Technology

Direct Sequence Spread Spectrum is a radio transmission technology that essentially applies a robust forward error correction scheme to the data-in-transit in order to minimize the effect of data loss due to signal interference. Specifically, DSSS encodes a set of data into a larger bit stream, or chips.

As seen to the left, CyFi solutions encode 8-bits of data into 32 chips. These chips are then modulated onto the RF signal and transmitted. The receiver demodulates the chips off of the received signal and then reverses the DSSS encoding scheme. Even with demodulation errors due to signal noise or interference, the original data can still be recovered. This technique ensures reliable communications without the need of retransmissions due to interference--a two-fold benefit of reliable communications and a boost in power-efficiency.

Reliability Through Frequency Agility

Channel hopping is an often complex technique of moving around the available RF spectrum to avoid interference. Some technologies are designed to constantly hop following an established and shared hopping algorithm while others hop only as needed or when facing overwhelming signal noise or interference. CyFi solutions employ the latter technique and minimize their movement around the spectrum except when absolutely necessary. This method prevents unnecessary hops and hub-searches further boosting performance and power-efficiency.

In addition, with only 1-MHz wide channels, CyFi solutions can easily avoid typical broadband technologies like 802.11b/g/n networks with 80 different channels to choose from--5-times as many than other technologies like 802.15.4.

CyFi is a


Measure Battery Life in Years, Not Weeks or Months

Besides very low active and sleep currents, CyFi solutions take a systems approach to power-efficiency. CyFi networks minimize periods of peak current consumption and maximize sleep. In some cases that means transmitting data as fast as possible. In others, it means enabling DSSS modulation, and possibly increasing RF output power, to eliminate the need for re-transmissions. CyFi networks automatically make these decisions in real-time and are the only low-power RF technology to do so.

As a battery-powered CyFi node moves closer to the network hub, it reduces its RF output power to minimize current consumption. This ensures that it will always use exactly as much current as needed to successfully transmit the data, and no more. CyFi solutions leverage their ultimate reliability to minimize costly on-air time and sleep more thus systematically reducing their overall power consumption.

CyFi is a PSoC Solution.

A Complete RF Sensor Solution in as few as Two Chips

Cypress's PSoC programmable system-on-chip combine dynamic, configurable analog and digital blocks and an 8-bit MCU on a single chip, replacing many discrete components while delivering the advanced flexibility and functionality designers need to meet aggressive schedules. Together with PSoC development software and kits, they form the industry most complete solution for embedded systems.

Further, a PSoC is uniquely advantageous in CyFi solutions due to their flexibility, integration and programmable analog capabilities which directly enable wireless embedded control solutions--as shown to the right.

Get Started with CyFi Low-Power RF

Everything you need to get started: Training, Kits, Software and Support


Cypress has training available to support you in a variety of formats including on-demand training over the Internet, hands-on workshops as well as live webinars.


Visit to find out more.

Visit the Get Started tab to learn about the kits designed to make evaluating, designing and developing with CyFi extremely easy.

If you are familiar with the PSoC programmable system-on-chip then you should already be familiar with its easy-to-use design environment, PSoC Designer. If not, we have additional training resources specifically for you as well to introduce you to the design environment and get you fast on your way to developing your embedded applications. Download PSoC Designer today and see how simple we have made embedded RF with CyFi.

Finally, Cypress is committed to supporting its most valued clients, you. The support resources we provide include a team of certified professional consultants and designers--our CYPros, phone-based support, electronic-based support via our online knowledge base as well as a variety of forums and environments for you to seek out frequently asked questions or interact with other Cypress developers--both internal and external. Visit for details on how to contact us or visit to find a local certified resource.