The RFD900 is a high performance 900MHz, ISM band radio modem covering the 902 – 928 MHz frequency band. It is designed for long range serial communications applications requiring best in class radio link performance.
- Long range >40km depending on antennas and GCS setup
- 2 x RP-SMA RF connectors, diversity switched.
- 1 Watt (+30dBm) transmit power.
- Transmit low pass filter.
- > 20dB Low noise amplifier.
- RX SAW filter.
- Passive front end band pass filter.
- Open source firmware / tools, field upgradeable, easy to configure.
- Small, light weight.
- Compatible with 3DR / Hope-RF radio modules.
- License free use in Australia, Canada, USA, NZ.
RFDesign RFD900 open source RF modem – [Link]
This project goes through the process of designing and building a simple RF transmitter and RF receiver pair that operate at 27 MHz. Only basic parts like 555 timers and 2N2222 transistors are used to make the modules, so it’s generic but fun.
The wireless modem you’ve been waiting for. Works with Arduino & other micros. Open source mesh networking base. FCC Certified. Cheap. Eric Gnoske writes:
So who’s behind RadioBlocks? A group of engineers who have worked on many aspects of low-power radio devices. A group of engineers who time & time again saw customers coming to us with similar requests, but with no way for us to easily fill them. So we created RadioBlocks to allow people to easily drop a radio link into their project, hence “RadioBlocks” – A simple to use radio building block.
Sure there are lots of radio boards out there. Most have two modes: super-simple serial-port replacement mode, and complex full network mode. Neither of those are useful – most people want to send some data between some devices. They need more than serial-port replacement, but the full network mode is too much hassle. Then many of those radio devices are just too expensive – are you really going to drop $30 or $40 on a single radio node, then buy extra hardware so you can attach sensors? Good luck with that!
RadioBlock: Simple Radio for Arduino or any Embedded System – [Link]
Dorji Applied Technology from China builds different types of RF modules that can be easily incorporated in designing wireless data loggers, sensor network, telemetry and other wireless applications.
Some of their RF modules have an additional preprogrammed microcontroller that allows direct interface of selected analog and digital sensors to the module. This means you don’t need any external MCU or to write codes for these sensors. In this tutorial, Raj from Embedded Lab talks about their DRF5150S and DRF4432S RF modules which are very versatile and easy to use for wireless sensor applications. For illustrative purpose, Raj shows how to put them together to construct a simple wireless sensor application where data from a remote sensor are received and displayed on a PC, without using any external microcontrollers.
Wireless sensor applications using Dorji’f DRF5150S and DRf4432S modules – [Link]
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.