Category Archives: RF

RFM22B/23B Availability and RFM69W

There is a degree of uncertainty at the moment regarding the future availability of HopeRF’s RFM22B and RFM23B modules.  Having been in touch with a number of HopeRF’s European distributors the message appears to be that while they are indeed “not recommended for new designs”, there has been no end-of-life notification for either of these products. [...]

Antenna Measurements – Part 1

I finally found the time to make some measurements on the printed antenna used on my sensor board, which I didn’t think was performing very well.  Turns out I was right. For this first part of the test various antenna configurations were tested by mounting them on unpopulated sensor boards connected to an Anritsu Sitemaster [...]

Implementing the ELV FHT Protocol with an RFM23

Over the last few weeks I have been helping out the guys over at OpenTRV with an implementation of the FHT protocol for use with HopeRF RFM22B and RFM23B modules.  My as-yet unreleased sensor modules (as seen in another post) make use of an RFM23B, and I have an interest in evaluating the Conrad/ELV FHT8V [...]

A Simple RF Protocol (or, what is the point of ZigBee?)

I’m going to start by admitting that this isn’t going to be a tirade of abuse against the oddly named 802.15.4-based wireless tech, but rather a request for comments on an open, lightweight alternative, particularly for low-cost sub-GHz applications.  I know what the point of ZigBee is, and the ability to form into self-organising mesh [...]

Wireless Sensor Boards Arrived

As part of my project to bring our central heating into the 21st century I have been working on a custom wireless sensor platform.  My key aim here is to develop a low-cost, open solution with security designed in from the start; something that a lot of sub-GHz protocols seem to totally omit.  I’m avoiding [...]

Hacking Wireless Radiator Valves with Gnuradio

A simple example of a custom Gnuradio block for decoding a proprietary sub-GHz radio protocol.