Stanford engineer aims to connect the world with ant-sized radios.
A Stanford engineering team has built a radio the size of an ant, a device so energy efficient that it gathers all the power it needs from the same electromagnetic waves that carry signals to its receiving antenna – no batteries required.
Designed to compute, execute and relay commands, this tiny wireless chip costs pennies to fabricate – making it cheap enough to become the missing link between the Internet as we know it and the linked-together smart gadgets envisioned in the “Internet of Things.”
Stanford engineer aims to connect the world with ant-sized radios - [Link]
Raffael @ code-bude.net build a webradio by himself. It’s made from an Arduino, an hacked TP-Link WR703N router and some interface parts.
Today I want to present you one of my larger craft projects. This time it is not just about software, but also about the associated hardware. What is it? A web radio!
I like to listen to internet radio stations, but I didn’t want to run my pc only for listening to webradios. Connecting my phone to my stereo either wasn’t a solution, since I’d rather wear this with me, because I don’t want to run for each SMS / Whatsapp message to the music system. And because I always like to tinker, it was obvious to build a web radio as a standalone device myself.
RadioduinoWRT – a do it yourself webradio - [Link]
Making an FM using TEA5767 module:
I’ve started to build a little FM radio with one of this cheap modules with a Phillip chip, the TEA5767. I will control it with a MSP430, probably I’ll use some kind of encoder to change stations and a potentiometer for the volume.
The TEA5767 is a single-chip electronically tuned FM stereo radio for low-voltage applications with fully integrated Intermediate Frequency (IF) selectivity and demodulation. Most of the information of this devices is from the datasheet and this app note.
Making an FM radio-Part 1; the TEA5767 - [Link]
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]
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]
Radio Arduino – uses Adafruit WaveShield!… [via]
What it is really doing is playing 24 music tracks that I preloaded onto an SD card in WAV format. There are also 10 tuning noises tracks that get played when the tuner is turned.
Because this is the first time I did this I had a lot of help. Firstly the chaps and chapesses at Hackspace have been very supportive in teaching me how to use and Arduino, particularly Adrian McEwan and Oomlout. Also Jingle Joe who supervised my soldering of the Wave Shield, Brox who helped me decipher the ancient mysteries of FAT16 and Esme who helped dismantle the original radio… PS I did do some of it myself!
Radio Arduino – uses Adafruit WaveShield! - [Link]
Free license study guides
Dan KB6NU writes:
Currently, I offer study guides for the first two license classes, the Technician Class and the General Class, and I’ll be publishing a study guide for the Extra Class license next year.
I call them “no nonsense” license study guides because all I cover are the questions that might appear on the test. The philosophy behind this is that the quicker someone gets a license, the sooner they’ll really be able to learn about the hobby, whether that’s electronics or antennas or propagation or whatever.
The study guides are available in three different formats:
- FREE! There’s a free PDF download available from my website.
- E-book. There are Kindle and Nook e-book versions available from the Amazon and Barnes&Noble websites. The cost for the e-book version is $7.99.
- Print. Yes, a dead tree version is available if you really want one. These cost $12, shipped, and are also available from my website.
Amateur Radio No-Nonsense Study Guides - [Link]
Ham radio is nothing new, however if your new to electronics, or interested in becoming a ham, we suggest reading one of Dan’s self-study guides. [via]
The RMS value of an AC signal is the voltage that causes the same power dissipation as
a DC voltage of the same value. (G5B07) For an AC signal with a sine-wave shape, the
RMS value is .707 times the peak value. 12 volts is the RMS voltage of a sine wave with
a value of 17 volts peak. (G5B09)
Conversely, the peak-to-peak value of an AC signal is 2 × 1.414 × the RMS value.
Accordingly, 339.4 volts is the peak-to-peak voltage of a sine wave that has an RMS
voltage of 120 volts. (G5B08)
Power is equal to the RMS voltage times the current, or
P (watts) = VRMS x I
Using Ohm’s Law, we can show that:
P = V2RMS / R
P = I2 x R
Amateur radio study guide has much information about electronics – [Link]
Here’s Jeri Ellsworth’s vlog showing her early progress on a homebrew software defined radio. Anyone who has considered SDR prototyping knows how complex this can be. We can’t wait to see the finished product.
UPDATE: Jeri has posted updates Part 2 and Part 3 to the above vlog.
Homebrew software defined radio, Jeri Ellsworth style – [Link]
NashblackCat writes to inform us of a chip that reads weather radio data: [via]
Silicon Laboratories makes an IC Weather Band (WB) radio called the Si4707. This IC is capable of using the specific area message encoding (SAME) and also supports the detection of the 1050Hz alert tone that is used by the National Weather Service. Currently no Arduino shields exist that could be used in a manner to receive, use, and/or display the broadcast alert data such as severe thunderstorm or tornado warnings. I think a shield like this would be great to implement all kinds of interfaces to this publicly available data resource. Some examples include Twitter alert system, VOIP streaming of audio broadcasts to your cellphone, and even a radio
Si4707 weather band radio receiver ICs – [Link]