Tag Archives: RF

Communication Between Two Arduinos Using NRF24L01


While building Arduino or any other microcontroller platform project over time the need will arise to establish communication between two of the Arduino boards or microcontrollers for data exchange and/or control. This communication could be achieved using either wired or wireless process. For wireless communication between devices, quite a number of options exist including WiFi, GSM/GPRS, Bluetooth, RF and more recent technologies like LoRaWAN among others. All of these communication protocols have their pros and cons and the situation is in which they are the best fit. For mid-range communication between two microcontrollers, for example, one of the most suitable communication protocol is RF (radio frequency) as it has a good cost to performance ratio and a very good communication range can be attained using certain modules.

Today, we will look at the radio frequency based communication between microcontrollers using one of the most popular RF communication modules; the NRF24L01 communication module.

The NRF24L01 module is a low-cost (less than$3) ultra-low power, bi-directional transceiver module. It is designed to operate within the 2.4GHz ISM band which means it can be used for projects with industrial, scientific and medical applications.  The module can achieve data rates as high as 2Mbits! and uses a high-speed SPI interface in order to communicate with the Arduino and other kind of microcontroller and development boards.

Communication Between Two Arduinos Using NRF24L01 – [Link]

Epiq Solutions Develops Wideband RF Transceiver SDR Module Running Linux On Zynq SoC

Epiq Solutions, a company from the USA, has included a new member of its Sidekiq line of Software-defined radio (SDR) add-on cards called the Sidekiq Z2. Dimensions of this card are only 51 x 30 x 5mm, the size of a full-size mini-PCIe card, the Sidekiq Z2 computer-on-module is advertised as “the world’s smallest wideband RF transceiver + Linux computer in a product-ready module”. The module is most suitable for handheld RF testing and measurement, remote RF sensing, wireless security applications, and CubeSat/UAS datalinks. A carrier board is also available with this module.

Sidekiq Z2 SDR Module
Sidekiq Z2 SDR Module

Unlike previous Sidekiq cards, the Sidekiq Z2 can act as a standalone computer, running Linux on a Xilinx Zynq-7000 series Arm/FPGA SoC. Like the original Sidekiq, which is available in mini-PCIe or M.2 form factors, the Sidekiq Z2 operates at 70MHz to 6GHz. There’s also a Sidekiq X2, which uses the VITA57.1 FMC form factor, which supports 1MHz to 6GHz frequencies.

Epiq claims, the new Sidekiq Z2 can boot Linux in under two seconds, with a typical system power consumption under 2 Watts. The Zynq comes with 512MB DDR3L RAM and 32MB QSPI flash. The SoC drives USB 2.0 OTG, serial UART, JTAG, and GPIO signals to a carrier board.

The shielded AD9634 1Rx + 1Tx transceiver has a 4-band Rx pre-select filter bank and an up to 61.44 Msamples/sec sample rate. The 40MHz TCVCXO ref clock features +/- 1 PPM stability. The 3.3V, 8-gram module supports -40 to 85°C temperatures. The module also offers many U.FL antenna connectors.

The company offers a Sidekiq Z2 Evaluation Kit (EVK) that includes two Sidekiq Z2 cards pre-loaded and supported by Analog Devices’ open source IIO reference design, along with two simple carrier cards. An optional Platform Development Kit (PDK) offers enhanced support and an optimized FPGA reference design to maximize processing capability of the FPGA. Epiq Solutions also presents applications for embedded RF spectrum analysis as well as 2G/3G/4G cellular network survey.

The Sidekiq Z2 is available now at a price of $649 for 1,000+ unit orders. The Sidekiq Z2 EVK and PDK also appear to be available, with pricing undisclosed. More information may be found in the Epiq Solutions Sidekiq Z2 announcement and product page.

Drones- A Blessing or a Curse?

The increasing popularity of unmanned aerial vehicles (drones) has created a lot of security issues and possible privacy threats. Drone manufacturers have made them easy to fly so that any person without any experience can buy one and fly it without reading the instruction manual first. This has made them attractive for consumers, but also for criminals. Most of them have a camera to allow the user to go to distances beyond their sight. As a result, drones are now being used by many companies to make deliveries such as Amazon, by people to take selfies, by explorers, by authorities etc. This increased amount of usage may pose security threats to privacy and commercial space.

For example, there is already reported cases of drones almost crashing into military aircrafts, or invading the helicopters flying area when trying to put out a forest fire, hacked drones, or drones being used to smuggle drugs. Additionally, there are a lot of reports involving drones constantly flying over private properties while recording. Drones are difficult to detect because of their size, so the company Aaronia produced a new drone detection system that tracks the high-frequency signal between these devices and it´s remote control.

The device consists of a IsoLOG 3D antenna, a Spectran V5 spectrum analyzer and a plug in for the RTSA software. It offers the user a long detection range, functionality in poor visibility, high resolution of signal detection, portability, drone identification etc.

This system provides detailed information of signal distribution, and can be combined with different devices to provide a bigger range of detection. It can be programmed to set off an alarm when some selected parameters are exceeded. The IsoLOG 3D has 16 sectors that provide full 360 RF spectrum overview including an image of the monitored area. It has W signal sensitivity and continuous data streaming with up to 4 TB per day.

Militaries could use this device to protect large areas, and even in the future to stop the drones from entering areas where they could interfere with life threatening situations or confidentiality sensitive scenarios. For now, only detection is possible, but it is a huge step toward fixing the security concern posed by drones. Some parts in the United States have already implemented laws to register all drones and to prohibit the users from flying them above certain heights and close to airports. These governmental measures can help the Aaronia device to easily identify the drones, and the device could help the authorities to stop people from breaking the law.


WattUp – RF based Wireless Charging at a Distance

WattUp Far Field Transmitter

Recently, many big companies such as Samsung have developed wireless chargers which work by induction. These chargers usually consist of a station which needs to be in contact with the device in order to charge. The station defeats the purpose of being able to move and walk while still charging the device. Energeous, a global leader in RF- based wireless charging, created the award-winning device WattUp in order to give mobile power to everyone.

The WattUp transmitter converts electricity into radio frequencies, then beams the energy to nearby devices that have the right receiving equipment. This system has proved to be more practical than induction since it can work from up to 3 feet away. Energeous wants to make a wire free charging ecosystem by taking into advantage the fact that the transmitter can charge multiple devices at a time, and as WIFI it would be able to charge your phone even if you are Samsung and the transmitter is Apple. All kind of devices can be charged using WattUp including (but not limited to) cameras, smartphones, tablets, wearables, and toys.

The receiver uses multiples antennas to collect the micro energy beams created by the transmitter (which makes it safe because power is received in small amounts). There is also an application available in which you can control the devices that are receiving power, how much power for each one, and even what times you want it charging. For example, you can prioritize cellphone charging in peak hours of use and leave other electronics to charge at night just with the click of a button.

The WattUp has already been FCC (federal communications commission) approved, and Energeous offers a variety of prices depending on the range of the transmitter, but it is still not available in the market. The company will be in CES 2018 showing their product, this event will take place on January 9th– 12th in Las Vegas.

Wireless charging not only benefits consumers, but also offers real benefits in terms of efficiency, productivity, and safety in industrial applications. Moreover, cables require maintenance and are easily damaged which makes them unreliable and expensive to maintain. In hospitals there is a constant need for big equipment that uses battery packs or cables, but to maintain a sterile environment WattUp could be a good alternative. Furthermore, in the future this technology could be used to power electric cars avoiding the need for charging every 10 to 40 miles.


Wireless power in AA battery format

Ossia has created the world’s first wirelessly-powered alternative to disposable AA batteries. The “Forever Battery” puts a long distance wireless power receiver into an AA battery format. The technology can receive up to 4W from a nearby RF transmitter (Cota transmitter), and includes a data link. [via]

Forever Battery bridges the gap between the battery-wire age and the wireless power era,” said Mario Obeidat, CEO of Ossia. “When people see how Cota Real Wireless Power can be implemented in a AA battery, they will start to see the vision of Cota everywhere. The Forever Battery will create awareness of Cota and provide confidence that devices will be powered when it matters.

Researchers Develop Long Range Backscatter Sensors That Consume Almost No Power

Researchers at the University of Washington developed a new backscatter sensors that can operate over long ranges with very little power. The researchers demonstrated for the first time that the device runs on almost zero power and can transmit data across distances of up to 2.8 kilometers.

The long-range backscatter system developed by UW researchers
The long-range backscatter system developed by UW researchers

Backscatter communication works by emitting a radio signal and then monitoring the reflections of that signal from sensors. As the transmitter generates the signal, the sensors themselves require very little power. But this kind of system badly suffers from noise. Noise can be added anywhere – on the transmitter side, on the channel or on the sensor array. The key to solving this problem is a new type of signal modulation called chirp spread spectrum.

By using the chirp spread spectrum modulation technique, the team was able to transmit data up to 2.8 kilometers while the sensors themselves consumed only a few microwatts of power. Such extremely low power consumption lets them run by harvested ambient energy and very small printed batteries. The cost is surprisingly cheap too. The sensors would cost just 10 to 20 cents per unit if bulk purchased.

Today’s flexible electronics and other sensors need to operate with very low power typically can’t communicate with other devices more than a few feet or meters away. By contrast, the University of Washinton’s long-range backscatter system achieved pretty strong coverage throughout a 4800-square-foot house, an office area including 41 rooms, and a one-acre vegetable farm at extremely low power and low cost.

Shyam Gollakota, the lead faculty and associate professor in the Paul G. Allen School of Computer Science & Engineering, said,

Until now, devices that can communicate over long distances have consumed a lot of power. The tradeoff in a low-power device that consumes microwatts of power is that its communication range is short. Now we’ve shown that we can offer both, which will be pretty game-changing for a lot of different industries and applications.

These low-power sensors have endless potential applications. They can be used for everything from wearable health monitors to scientific data collection devices. Though there are no confirmed products yet, the team has created few prototypes in the form of flexible sensors worn on the skin, smart contact lenses, and more.

ERASynth, An Arduino-Compatible RF Signal Generator

A young startup based in Istanbul has launched a crowdfunding campaign to bring its RF Signal Generator “ERASynth” into mass production. ERA Instruments is specializing in creating solutions in the areas of analysis, modelling, design and development of Communcation, RADAR and SIGINT systems.

ERASynth is a portable analog signal generator that generates RF frequencies from 250 kHz to 15 GHz. The output signal is produced using an advanced multiloop PLL architecture to minimize the phase noise and spurious. This clean signal can be used as a stimulus source for RF testing, an LO source for down-conversion or up-conversion, a clock source for data converters, and as a test signal source for software defined radio (SDR).

ERASynth Features & Specifications

  • Architecture: Multiloop Integer-N PLL driven by a tunable reference. No fractional-N or integer boundary spurs
  • Frequency Range:
    • ERASynth: 10 MHz to 6 GHz
    • ERASynth+: 250 kHz to 15 GHz
  • Amplitude Range: -60 to +15 dBm
  • Phase Noise: typical phase noise @ 1 GHz output and 10 kHz offset. -120 dBc/Hz for the standard version and -125 dBc/Hz the plus version.
  • Frequency Switching Time: 100 µs
  • Reference: Ultra-low noise 100 MHz VCXO locked to a ±0.5 ppm TCXO for standard version and ±25 ppb OCXO for the plus one.
  • MCU: Arduino Due board with BGA package Atmel Microcontroller (ATSAM3X8EA-CU)
  • Interfaces:
    • Wi-Fi interface for web-based GUI access
    • Serial-USB (mini USB) for serial access
    • Micro USB for power input
    • Trigger Input (SMA) for triggered sweep
    • REF In (SMA) for external reference input
    • REF Out (SMA) for 10 MHz reference output
    • RF Out
  • Dimensions: 10 cm x 14.5 cm x 2 cm
  • Weight: < 350 g (12.5 oz)
  • Power Input: 5 to 12 V
  • Power Consumption:
    • < 6 W for ERASynth
    • < 7 W for ERASynth+
  • Enclosure: Precision-milled, nickel-plated aluminum case
  • Open Source: Schematics, embedded Arduino code, Web GUI source code, and RS-232 command set

ERASynth is only 10 x 14.5 x 2 cm sized and it is consuming less than 7 Watts. It can be powered by a cell phone power-bank. Inclusion of an on-board Wi-Fi module and an open source web GUI makes ERASynth ideal for portable applications. Also its price make it affordable by everyone including makers, students, universities, research labs, and startups.

Compared with other low cost USB signal generators, ERASynth provides better features in many factors. It also delivers similar functionality of the professional RF signal generator with lower price. The tables below demonstrate the comparison.

The crowdfunding campaign on Crowd Supply will be closed by tomorrow, they raised about $35,000 of $25,000 goal. You can order your ERASynth for $500 and ERASynth+ for $750. More technical details are available on the campaign page.

PandwaRF, A Portable Radio Analysis Tool

PandwaRF, is a portable low-power RF device that captures, analyses and re-transmits RF signals via an Android device or a Linux PC. It uses Bluetooth (BLE) or USB connection to transmit data in a simple and fast way, comes in the form of a controllable housing from a smartphone or a computer.

This pocket-size device operates at sub-1 GHz range, and it replaced the ‘standard SDR Grind’ of capturing, demodulating, analyzing, modifying and replaying by hand with a simple powerful interface.

The PandwaRF consists of a capable hardware device, tailored for beginners and advanced users, with an application that runs either on an Android device or on a PC. The Android interface provides full functionality to control and customize the PandwaRF easily using JavaScript.

Technical details of the PandwaRF:

  • Bluetooth Smart Module ISP130301, based on nRF51
  • CC1111 Low-Power SoC with Sub-1 GHz RF Transceiver
  • Multi frequencies (from 300 MHz to 928 MHz)
  • Multi modulation (ASK/OOK/MSK/2-FSK/GFSK)
  • Transmit and receive in half duplex mode
  • Support data rates up to 500 kBaud
  • Open hardware
  • Full speed USB: 12 Mbps (Linux or Android)
  • Bluetooth Smart 4.0 (Android/iOS)
  • USB charging & battery powered
  • 4 buttons to assign codes
  • 4 Status LEDs
  • 16 Mbit Flash Memory to save custom RF protocols
  • Rechargeable battery powered for stand-alone operation
  • Battery fuel gauge
  • RX amplifier for improved sensitivity: +13dB from 300MHz-1GHz
  • TX amplifier for higher output power: +20dB @ 433MHz & +17dB @ 900MHz
  • SMA connector for external antenna
  • Antenna port power control for external LNA
  • 22-pin expansion and programming header
  • Included: Battery and injection molded plastic enclosure

PandwaRF features are not fully complete yet, the developers had finished captured data processing offload, radio scripting (JavaScript & Python), RF packet sniffer, and spectrum analyzer. Other features are still in development process.

The device is available in three options, the Bare version is about $120 and comes without housing and without battery, the standard version is about $142 with battery and black case, in addition the extended version with enhanced features.

You can reach more information and order your PandwaRF on the official website.

6 Channel RF Remote Controller Using CC2500 RF Modules

The 6 Channel RF Remote Controller designed using CC2500 RF Transceiver modules and PIC16F1847 micro-controller from microchip. Transmitter provided with 6 tact switch, 4 Address Jumpers to pair multiple unit so they don’t interfere with each other. Board provided with power LED, valid transmission LED. Project works with 5 V DC, On board LM1117-3.3V regulator for CC2500 Module.  Two in one PCB can be used as Transmitter & Receiver.

Receiver works with 5V DC. 4 Jumper to paring RX& TX units, valid signal LED, power LED, and 9 Pin connector for outputs.  Same PCB is used as transmitter and receiver.  All outputs are Latch Type and TTL 5V Signal for easy interface with other devices like Relay Boards, Solid State Relays.

6 Channel RF Remote Controller Using CC2500 RF Modules – [Link]

Siglent SSA3032X Spectrum Analyzer Review & Experiments

Afroman reviews Siglent’s SSA3000X series spectrum analyzer and all the options. There is some RF information for beginners and usage experiments are also performed.

Siglent SSA3032X Spectrum Analyzer Review & Experiments [Link]