Collaborate Disseminate
If you have an RTL-SDR compatible radio there’s an excellent chance you’ve heard of the rtl_433 project, which lets you receive and decode signals from an ever-expanding list of supported …read more Continue reading Arduino Library Brings rtl_433 to the ESP32
[Mare] has a visual guide and simple instructions for making DIY mini helical 868 MHz antennas for LoRa applications. 868 MHz is a license-free band in Europe, and this method yields a perfectly serviceable antenna that’s useful where space is constrained.
The process is simple and well-documented, but as usual with antenna design it requires attention to detail. Wire for the antenna is silver-plated copper, salvaged from the core of RG214U coaxial cable. After straightening, the wire is wound tightly around a 5 mm core. 7 turns are each carefully spaced 2 mm apart. After that, it’s just a matter …read more
Continue reading DIY Mini Helical Antennas From Salvaged Co-ax Cable
If you own one of the ubiquitous RTL-SDR software defined radio receivers derived from a USB digital TV receiver, one of the first things you may have done with it was to snoop on wide frequency bands using the waterfall view present in most SDR software. Since the VHF and UHF bands the RTL covers are sometimes a little devoid of signals, chances are you homed in upon one of the ISM bands as used by plenty of inexpensive wireless devices for all sorts of mundane control tasks. Unless you reside in the depths of the wilderness, ISM band sniffing …read more
Continue reading Attack Some Wireless Devices With A Raspberry Pi And An RTL-SDR
If you want to wirelessly communicate between devices, WiFi and Bluetooth are obvious choices. But there’s also the ISM (industrial, scientific, and medical) band that you use. There are inexpensive modules like the SX1278 that can handle this for you using LoRa modulation, but they haven’t been handy to use with an Arduino. [Jan] noticed the same thing and set out to build a shield that allowed an Arduino to communicate using LoRa. You can find the design data on GitHub. [Jan] calls it the LoRenz shield.
According to [Jan], the boards cost about $20 to $30 each to make, …read more
[Johan Kanflo] sent us his latest recipe: a blend of one part RFM69 sub-gigahertz radio transceiver with one part ESP8266 module. The resulting dish looks absolutely delicious!
We’re all charmed with the ease of use that the ESP8266 brings to the table — plug it in and you’re talking to your existing WiFi network — but we hate the power consumption for battery-powered applications. WiFi is a power hog. And although ISM-band radio modules make point-to-point communications cheap and power-saving, getting them to talk with your computer takes an adapter.
So [Johan] combined the two radios and made a sweet …read more
