June 17, 2016

LimeSDR CrowdFunding Closing in Four Days: 80% Funded

The LimeSDR is a new transmit capable software defined radio with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth which is currently seeking crowdfunding. At the time of this post there is about four days left to reach the $500k goal, and it is only 80% funded. To try and reach their funding goal they have released another batch of discounted units which cost only $249 USD. After the crowd funding campaign the price will rise to $289/$299 USD. If the LimeSDR is not funded in time, they write that the project will unfortunately be put on hold and it’s future may be uncertain. We believe that this product is shaping up to be a very good TX/RX capable SDR, like the HackRF and bladeRF, but much better overall and for the same or even lower price.

Recently they also released some new updates that show off some LimeSDR features. In a post previously featured on our blog beta tester Alexandru showed how he was able to get the LimeSDR to transmit DVB-S2 HDTV. In later updates they showed how the LimeSDR can be used to:

Reverse engineer and then control an off the shelf RF mains switch. They then combined it with a Bluetooth LE wireless temperature sensor and used Pothos to create a program that automatically turns the mains switch on or off depending on temperature.
Control LoRa based IoT devices. In this post they used the LimeSDR to demonstrate how it can be used to transmit to, receive and simulate IoT devices running the popular LoRa wireless protocol
Create a 10 MHz LTE cellular site. In this post they also show a mobile phone connecting to the cell site and using LTE mobile internet at 20MSPS.
Create a spectrum analyzer, oscilloscope and signal generator in GNU Octave. Here they show how the LimeSDR can be used as an “all-in-one” lab tool replacement for several expensive devices.
Create a Vector Network Analyzer. With the help of a directional coupler the LimeSDR can also be turned into a Vector Network Analyzer to measure parameters such as gain, insertion loss, return loss and VSWR.
Build a remote radio head. By mounting the LimeSDR near the antenna and streaming the data back over an IP link, coax feed losses can be eliminated.

February 1, 2016

Decoding the LoRa IoT Protocol with an RTL-SDR

The internet of things is set to become the next big thing in technology. The IoT consists of multiple networked devices such as sensors and computers connected in various ways such as via wireless communication protocols. LoRa is an abbreviation of “Long Range” and is one such wireless protocol that is being used in IoT devices.

[LoRa] is a radio modulation format that gives longer range than straight FSK modulation. This is achieved by a combination of methods: it uses a spread spectrum technique called Chirp Spread Spectrum (CSS) and it uses forward error coding (in combination with whitening and interleaving).

Over at the RevSpace hackerspace, a hardware hacker called bertrik has been working with his RTL-SDR to try and reverse engineer the LoRa protocol. His goal is to make it so that anyone can receive and decode LoRa signals without needing to purchase specific hardware that supports the modulation. The reverse engineering work is not yet finished, but bertrik has already determined many parts of the protocol by looking at the signals in Audacity. He also writes that there is currently a ready made LoRa decoder available for sdrangelove, a Linux based SDR receiver application similar to GQRX and SDR#.

You might also be interested in this previous article we posted about the Z-Wave wireless networking protocol being hacked with a HackRF.

LoRa signals received in the frequency spectrum.