This is my favourite project, its too simple and very interesting because it does not require any voltage source 😀 it converts RF frequency waves from cell phone (whenever you call or send a text) to little current to flash a LED.
Actually this project is also called as LED power meter, it is used to test RF equipments. It can detect output power of our FM transmitters, by simply connecting voltmeter in the place of the load(LED) of this circuit.
Cell phone RF radiation Detector – [Link]
panStamp is an open source project created for the enthusiasts that love measuring and controlling things wirelessly. panStamps are small wireless boards specially designed to fit in low-power applications, simple to program and simple to work with. With panStamps, you can measure almost everything by simply connecting your panStamp to the sensors, placing a battery and sending wireless data from the first moment.
panStamps are suitable for any kind of project needing remote control and low-power wireless transmissions, including home automation, energy metering, weather monitoring and robot control. If you are one of these three things: a hobbyist, a professional or an end-user, you will find that panStamps provide extreme flexibility and power when creating custom wireless networks.
Low-power Arduino based wireless solution – [Link]
IRVINE, CA — June 19, 2012 — Open Source RF, a new venture dedicated to serving Arduino users by making high-quality, creative products for the Maker, DIY and Open Source communities, today announced it is releasing a plug and play wireless Shield for Arduino.
The Wireless Inventors Shield makes any Arduino project wireless instantly even in high-traffic areas. Using a reliable wireless RF module, the Shield allows users to easily send and receive error-free data between two or more Arduino boards.
Arduino is an open source electronics prototyping platform based on flexible, easy-to-use hardware and software. It is intended for artists, designers, hobbyists and anyone interested in creating interactive objects or environments.
The Wireless Inventors Shield has been tested at ranges in excess of 500 feet (150 meters); it is plug and play and error free, featuring built-in forward error correction and data recovery so users receive only cleaned and cyclic redundancy checked (CRC) verified data; and it is simple to use in that inputted data is wirelessly transmitted then cleanly received on the opposite end. Read the rest of this entry »
Getting into microwave but having problems finding an accurate method of measuring the RF power at these frequencies? If you are like me, you can’t afford to buy even a used HP 432, 435 or 436 version power meter via eBay. I have to admit I was tempted recently when I spotted a HP435A listed for here in Australia and then noted that there was no sensor with it. Quite a while later after searching eBay for sensors, I came away for a reality check – I might get the 435A for under $200 but a suitable sensor was going to cost somewhat more than $300. Sorry, but $500 doesn’t figure into my budget for a device which might be up to 40 years old, with calibration status unknown and sensor status questionable – and expensive to repair if damaged.
DIY Microwave RF Power Meter – 100MHz – 12GHz – [Link]
The excellent book on transmitters that offer contains 467 pages of information in English about transmitters. Radio Transmitters was published in 1961 by engineers at the laboratory of ITT radio transmission.
Here’s a whole book dedicated to transmitters! Targeted at professional engineers rather than hams, this covers it all from oscillators through power amps, modulators, power supplies, and antenna matching.
Radio Transmitters – Tube power RF Circuits – [Link]
The identification for the Amidon toroids consists of one or two letters (T=toroid and FT=ferrite toroid), followed by a number (for ex. T50), which represents the outer diameter dimension expressed in 0,1 inches, followed by a separation mark (dash, dot, stroke), followed by another number indicating the frequency mixture and the frequency range at which it would be recommended to use the toroid.
It should be taken in account that a toroid with a X declared frequency will be able to operate with fairly good performances even at 10 times higher frequencies and only the A factor will decrease.
The iron powder toroids are colored according to their mixture; the first color covers three sides and the second color the remaining side.
Simple software to calculate the air core coils, the most widely used in RF circuits and may use the software to determine the data to build a coil, knowing that the inductance of this coil. The software will give the result of how many turns will be required to achieve certain inductance value, and provides the wire diameter … In addition has a table with wires AWG mm thick.
The light weight, compact size and low cost DSA800 family of spectrum analyzers from Rigol Technologies feature digital IF technology to provide the reliability and performance necessary for RF applications. The spectrum analyzers have a frequency range of 9 kHz to 1.5 GHz with a typical displayed average noise level (DANL) of ‑135 dBm. SSB offset phase noise is typically -80 dBc/Hz at 10 kHz, and the resolution bandwidth is adjustable from 100 Hz to 1 MHz. A preamplifier and AM/FM demodulation are standard with this instrument. [via]
Low-Cost Spectrum Analysers Feature 1.5 GHz Top End – [Link]
Sergei Bezrukov writes:
In this project we send and receive digital data by using a 433MHz transmitter and receiver modules TXM-433 and RXM-433 manufactured by LINX. We also use LINX helical whip-style antennas. The following images show the first part of the project – assembling the modules on a PCB and establishing RF connection between them.
Transmitting digital data over RF with LINX modules – [Link]
Here’s an app note about a circuit for detecting and locating radio frequency transmitters. The circuit is based around the MAX2015 RF detector which outputs a voltage proportional to the strength of a received RF signal in the 100 MHz to 3 GHz range – [via]
This design idea showcases a circuit that detects RF “bugs,” such as hidden wireless cameras, eavesdropping microphones, and other spying devices that emit RF frequencies in the 100MHz to 3000MHz range. A modification to this circuit not only detects RF bugs, but also locates their hidden positions.
App note: Detecting and locating RF bugs – [Link]
One of the first companies to focus on Wi-Fi was the AsyncLabs, who proposed a famous WiFi shield, including the appropriate libraries. What we propose is a new solution for Wi-Fi: this is a shield that the hardware was inspired by that of AsyncLabs, but in addition, we have provided a slot for microSD memory.
The basic component of the shield that we have made is a Wi-Fi module MRF24WB0MA manufactured by Microchip. The device is a Wi-Fi IEEE 802.11 RF transceiver, with a data rate between 1 and 2 Mbps, and with an internal antenna.
The WiFi shield supports both types of wireless networks infrastructure (BSS) and ad-hoc (IBSS) and is also allowed to connect to secure networks (cryptographers and are supported 64 and 128-bit WEP, WPA/WPA2 and TKIP, AES and PSK).
The library is constantly evolving, so we have provided a space where they will be published on http://code.google.com/p/wifi-shield-oe/ various versions available. http://www.open-electronics.org/arduino-wifi-shield/
Arduino WiFi Shield – [Link]