Tagged: limesdr

SignalsEverywhere Tutorial: Updating LimeSDR Mini Firmware and Installing Drivers

Over on his YouTube channel SignalsEverywhere, Corrosive has uploaded a tutorial video that shows how to update the LimeSDR firmware and drivers. The LimeSDR Mini is a US$159 12-bit TX/RX capable SDR that can tune between 10 MHz – 3.5 GHz, with a maximum bandwidth of up to 30.72 MHz. The specs and price of the LimeSDR mini are pretty good, but documentation for actually using it can be a bit confusing, so videos like Corrosive's tutorial are great.

LimeSDR Mini Tutorial Drivers and Firmware Update on Windows 7/10

Using a LimeSDR / PlutoSDR to Transmit Digital Amateur Television with DATV Express

Over on YouTube Corrosive from channel SignalsEverywhere has uploaded a new video in his series on Digital Amateur Television (DATV). The new video shows us how to use a transmit capable SDR like a LimeSDR or PlutoSDR to transmit DATV with a free Windows program called DATV Express.

In the video he explains the various transmit and video encoding settings, and then demonstrates the signal being received on SDRAngel with an RTL-SDR (which he explained in his previous video)

Transmitting DVB-S DATV Digital Amateur Television with LimeSDR / Pluto on Windows with DATV Express

A LimeSDR Mini Based Doppler Radar

Thanks to Luigi (aka @luigifcruz and PU2SPY) for writing in and submitting to us his LimeSDR based doppler radar blog post. The LimeSDR Mini is a low cost two port TX and RX capable SDR. Luigi's doppler based radar makes use of one TX port to transmit the radar signal, and the RX port to receive the reflection. The idea is that the if the object being measured is moving, the received reflected signal will be altered in phase due to the doppler effect.

In terms of hardware, Luigi's radar uses the LimeSDR Mini as the TX/RX radio, a Raspberry Pi 3 as the computing hardware, an SPF5189Z based LNA on the RX side, and two cantenna antennas. It transmits a continuous wave signal at 2.4 GHz.

Luigi's LimeSDR Based Doppler Radar
Luigi's LimeSDR Based Doppler Radar

On the software side it uses a GNU Radio program to transmit, receive and process the returned signal. Luigi's post goes over the DSP concepts in greater detail, but the basic idea is to measure the phase shift between the transmitted and reflected signal via a Multiply Conjugate block, and then decimate the output to increase the resolution. The result is then output on a frequency domain waterfall graph. The GNU Radio is all open source and available on Luigi's Github.

In order to test the system Luigi first set up a test to measure an electric fan's blade speed. The result was clearly visible line in the spectrogram which moved depending on the speed setting that the fan was set to.

Software Defined Radar - Continuous Wave Doppler Radar w/ LimeSDR

In his second test Luigi measures the speed of vehicles by placing the radar on the sidewalk, pointed at cars. The result was clear indication of the vehicle passes as shown by the longer vertical lines on the graph below. The smaller lines have been attributed to pedestrians passing by.

LimeSDR Vehicle Doppler Radar Results: Each long line indicates a vehicle, and shorter lines indicate pedestrians.
LimeSDR Vehicle Doppler Radar Results: Each long line indicates a vehicle, and shorter lines indicate pedestrians.

In a third test, Luigi measured vehicle speeds in tougher conditions, with the radar placed 50 meters away from the highway, at 45 degrees, and with weeds in the way. The radar still generated obvious lines indicating vehicles passes. Finally, in his fourth test, Luigi tested the speed accuracy of his radar by measuring a car driving at a known speed. The results showed excellent accuracy.

Software Defined Radar - Continuous Wave Doppler Radar w/ LimeSDR

LimeNET Micro Now Crowdfunding

Lime Microsystems, creators of the LimeSDR, LimeSDR Mini and LimeNET SDR devices have recently begun crowdfunding for a new product they are calling LimeNET Micro. LimeNET Micro is described as a software defined radio platform with an integrated processor for creating self contained wireless networks. In other words it is a LimeSDR LMS7002M SDR transceiver chip with an included Raspberry Pi Compute Module 3, FPGA, GNSS module, EEPROM and Flash memory attached to it.

The LimeNET Micro is capable of full duplex TX and RX (1 port each) with the typical LimeSDR frequency range of 10 MHz - 3.5 GHz. However a major difference is that the LimeNET Micro is only capable of a 0.27 MHz bandwidth, whereas other LimeSDR products are capable of bandwidths up to 30.72 MHz. One interesting additional feature is that the LimeSDR Micro comes with a GNSS module that can be used to receive GPS/GLONASS etc for high accuracy timing if required.

Some use cases that they envision LimeNET micro being useful for include:

  • Inexpensive enterprise and personal networks
  • Rural, autonomous, and resilient networks
  • Universal IoT communications hubs
  • Rapid deployment infrastructure for emergency response
  • Remote radio solutions for amateur radio and radio astronomy
  • Integration into application-specific RF appliances
  • Radio spectrum survey
  • Passive wireless geolocation
  • PHY and security research
  • RF-aware robotics

The price is $269 USD and this includes a Raspberry Pi Compute Module 3. Higher end kits can be purchased which include Acrylic ($399) or Aluminum enclosures ($459).

LimeNET Micro with Raspberry Pi Compute 3 Module attached.
LimeNET Micro with Raspberry Pi Compute 3 Module attached.

Using a LimeSDR To Detect Aircraft Reflections from a 2.3 GHz Beacon

Over on his blog author Daniel Estevez has described how he's been listening to aircraft reflections from a 2.3 GHz 2W beacon. The beacon is 10km away from Daniels location and transmits a tone and CW identification at 2320.865 MHz. As aircraft fly nearby to his location Daniel was able to observe aircraft reflections of the beacon, and was able to match them with ADS-B position and velocity reports.

The hardware that he used was a LimeSDR and a 9dBi 2.4GHz planar WiFi antenna patch. By aiming the antenna away from the transmitter, and using his car as a shield to block the transmitter he was able to receive some reflections. Daniel recorded several reflections including one produced by a nearby car.

By combining his results with ADS-B data he was able to superimpose the results, and color aircraft tracks by either a negative or positive doppler shift which was observed from the reflection. By combining the ADS-B data with the time stamps, he was also able to mark the reflections from each aircraft.

Marking Aircraft Reflections at 2.3 GHz against ADS-B Data
Marking Aircraft Reflections at 2.3 GHz against ADS-B Data

Transmitting and Receiving DATV with a LimeSDR and a Modified $20 DVB-S Receiver

Over on YouTube user Corrosive has uploaded a video showing how he can use the recently updated DATV Express software to transmit Digital Amateur TV (DATV) with a LimeSDR Mini, and receive it with a cheap US$20 DVB-S satellite set top box that he's modified with a custom firmware update. Corrosives work is excellent as it allows anyone to get started in DATV amateur radio cheaply. He writes:

Last week I noticed the windows DATV express software for windows had been updated to include several SDR platforms [appears to now support the LimeSDR and LimeSDR Mini, as well as the PlutoSDR] https://www.datv-express.com/CustomPage/Downloads

Using my new LimeSDR Mini I wanted to try this out. I went online and purchased a cheap DVB-S Satellite set top box on eBay branded as a KOQIT K1Mini.

In order to allow the KOQIT K1Mini DVB-S set top box to receive DATV frequencies, Corrosive has released a firmware update on GitHub that removes all satellites listed in the receiver, and replaces it with six DATV channels for amateur television use. He writes:

I decided to split the 3 23cm ATV frequencies into 6 at half the bandwidth for digital.

The receiver with my firmware configures the device to see a 9750LO LNB, by placing a simple antenna on the receiver instead of an LNB the 1.2 ghz amateur frequencies are shifted by 9750mhz and can be scanned as if they were a satellite transponder.

If you don't have a TX capable or DATV Express compatible SDR like the LimeSDR or Pluto, then we note that RPiTX (software that allows a Raspberry Pi to transmit RF without any additional hardware) also has DATV transmit capabilities that could in used in their place.

Digital DVB-S Amateur Television Station With LimeSDR Mini and a Satellite Receiver 23CM 1.2GHz

datv_limesdr_koqit_corrosive
datv_limesdr_koqitdvbs
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SignalsEverywhere Tutorial: Updating LimeSDR Mini Firmware and Installing Drivers

Over on his YouTube channel SignalsEverywhere, Corrosive has uploaded a tutorial video that shows how to update the LimeSDR firmware and drivers. The LimeSDR Mini is a US$159 12-bit TX/RX capable SDR that can tune between 10 MHz – 3.5 GHz, with a maximum bandwidth of up to 30.72 MHz. The specs and price of the LimeSDR mini are pretty good, but documentation for actually using it can be a bit confusing, so videos like Corrosive's tutorial are great.

LimeSDR Mini Tutorial Drivers and Firmware Update on Windows 7/10

Using a LimeSDR / PlutoSDR to Transmit Digital Amateur Television with DATV Express

Over on YouTube Corrosive from channel SignalsEverywhere has uploaded a new video in his series on Digital Amateur Television (DATV). The new video shows us how to use a transmit capable SDR like a LimeSDR or PlutoSDR to transmit DATV with a free Windows program called DATV Express.

In the video he explains the various transmit and video encoding settings, and then demonstrates the signal being received on SDRAngel with an RTL-SDR (which he explained in his previous video)

Transmitting DVB-S DATV Digital Amateur Television with LimeSDR / Pluto on Windows with DATV Express

A LimeSDR Mini Based Doppler Radar

Thanks to Luigi (aka @luigifcruz and PU2SPY) for writing in and submitting to us his LimeSDR based doppler radar blog post. The LimeSDR Mini is a low cost two port TX and RX capable SDR. Luigi's doppler based radar makes use of one TX port to transmit the radar signal, and the RX port to receive the reflection. The idea is that the if the object being measured is moving, the received reflected signal will be altered in phase due to the doppler effect.

In terms of hardware, Luigi's radar uses the LimeSDR Mini as the TX/RX radio, a Raspberry Pi 3 as the computing hardware, an SPF5189Z based LNA on the RX side, and two cantenna antennas. It transmits a continuous wave signal at 2.4 GHz.

Luigi's LimeSDR Based Doppler Radar
Luigi's LimeSDR Based Doppler Radar

On the software side it uses a GNU Radio program to transmit, receive and process the returned signal. Luigi's post goes over the DSP concepts in greater detail, but the basic idea is to measure the phase shift between the transmitted and reflected signal via a Multiply Conjugate block, and then decimate the output to increase the resolution. The result is then output on a frequency domain waterfall graph. The GNU Radio is all open source and available on Luigi's Github.

In order to test the system Luigi first set up a test to measure an electric fan's blade speed. The result was clearly visible line in the spectrogram which moved depending on the speed setting that the fan was set to.

Software Defined Radar - Continuous Wave Doppler Radar w/ LimeSDR

In his second test Luigi measures the speed of vehicles by placing the radar on the sidewalk, pointed at cars. The result was clear indication of the vehicle passes as shown by the longer vertical lines on the graph below. The smaller lines have been attributed to pedestrians passing by.

LimeSDR Vehicle Doppler Radar Results: Each long line indicates a vehicle, and shorter lines indicate pedestrians.
LimeSDR Vehicle Doppler Radar Results: Each long line indicates a vehicle, and shorter lines indicate pedestrians.

In a third test, Luigi measured vehicle speeds in tougher conditions, with the radar placed 50 meters away from the highway, at 45 degrees, and with weeds in the way. The radar still generated obvious lines indicating vehicles passes. Finally, in his fourth test, Luigi tested the speed accuracy of his radar by measuring a car driving at a known speed. The results showed excellent accuracy.

Software Defined Radar - Continuous Wave Doppler Radar w/ LimeSDR

LimeNET Micro Now Crowdfunding

Lime Microsystems, creators of the LimeSDR, LimeSDR Mini and LimeNET SDR devices have recently begun crowdfunding for a new product they are calling LimeNET Micro. LimeNET Micro is described as a software defined radio platform with an integrated processor for creating self contained wireless networks. In other words it is a LimeSDR LMS7002M SDR transceiver chip with an included Raspberry Pi Compute Module 3, FPGA, GNSS module, EEPROM and Flash memory attached to it.

The LimeNET Micro is capable of full duplex TX and RX (1 port each) with the typical LimeSDR frequency range of 10 MHz - 3.5 GHz. However a major difference is that the LimeNET Micro is only capable of a 0.27 MHz bandwidth, whereas other LimeSDR products are capable of bandwidths up to 30.72 MHz. One interesting additional feature is that the LimeSDR Micro comes with a GNSS module that can be used to receive GPS/GLONASS etc for high accuracy timing if required.

Some use cases that they envision LimeNET micro being useful for include:

  • Inexpensive enterprise and personal networks
  • Rural, autonomous, and resilient networks
  • Universal IoT communications hubs
  • Rapid deployment infrastructure for emergency response
  • Remote radio solutions for amateur radio and radio astronomy
  • Integration into application-specific RF appliances
  • Radio spectrum survey
  • Passive wireless geolocation
  • PHY and security research
  • RF-aware robotics

The price is $269 USD and this includes a Raspberry Pi Compute Module 3. Higher end kits can be purchased which include Acrylic ($399) or Aluminum enclosures ($459).

LimeNET Micro with Raspberry Pi Compute 3 Module attached.
LimeNET Micro with Raspberry Pi Compute 3 Module attached.

Using a LimeSDR To Detect Aircraft Reflections from a 2.3 GHz Beacon

Over on his blog author Daniel Estevez has described how he's been listening to aircraft reflections from a 2.3 GHz 2W beacon. The beacon is 10km away from Daniels location and transmits a tone and CW identification at 2320.865 MHz. As aircraft fly nearby to his location Daniel was able to observe aircraft reflections of the beacon, and was able to match them with ADS-B position and velocity reports.

The hardware that he used was a LimeSDR and a 9dBi 2.4GHz planar WiFi antenna patch. By aiming the antenna away from the transmitter, and using his car as a shield to block the transmitter he was able to receive some reflections. Daniel recorded several reflections including one produced by a nearby car.

By combining his results with ADS-B data he was able to superimpose the results, and color aircraft tracks by either a negative or positive doppler shift which was observed from the reflection. By combining the ADS-B data with the time stamps, he was also able to mark the reflections from each aircraft.

Marking Aircraft Reflections at 2.3 GHz against ADS-B Data
Marking Aircraft Reflections at 2.3 GHz against ADS-B Data

Transmitting and Receiving DATV with a LimeSDR and a Modified $20 DVB-S Receiver

Over on YouTube user Corrosive has uploaded a video showing how he can use the recently updated DATV Express software to transmit Digital Amateur TV (DATV) with a LimeSDR Mini, and receive it with a cheap US$20 DVB-S satellite set top box that he's modified with a custom firmware update. Corrosives work is excellent as it allows anyone to get started in DATV amateur radio cheaply. He writes:

Last week I noticed the windows DATV express software for windows had been updated to include several SDR platforms [appears to now support the LimeSDR and LimeSDR Mini, as well as the PlutoSDR] https://www.datv-express.com/CustomPage/Downloads

Using my new LimeSDR Mini I wanted to try this out. I went online and purchased a cheap DVB-S Satellite set top box on eBay branded as a KOQIT K1Mini.

In order to allow the KOQIT K1Mini DVB-S set top box to receive DATV frequencies, Corrosive has released a firmware update on GitHub that removes all satellites listed in the receiver, and replaces it with six DATV channels for amateur television use. He writes:

I decided to split the 3 23cm ATV frequencies into 6 at half the bandwidth for digital.

The receiver with my firmware configures the device to see a 9750LO LNB, by placing a simple antenna on the receiver instead of an LNB the 1.2 ghz amateur frequencies are shifted by 9750mhz and can be scanned as if they were a satellite transponder.

If you don't have a TX capable or DATV Express compatible SDR like the LimeSDR or Pluto, then we note that RPiTX (software that allows a Raspberry Pi to transmit RF without any additional hardware) also has DATV transmit capabilities that could in used in their place.

Digital DVB-S Amateur Television Station With LimeSDR Mini and a Satellite Receiver 23CM 1.2GHz

datv_limesdr_koqit_corrosive
datv_limesdr_koqitdvbs
Loading image... Loading image...

Using a LimeSDR to Implement Software Defined Optoelectronic Systems

Back in January of this year we posted about PhD student Lucas Riobó's work that about about using an RTL-SDR to create a low cost optical "high-speed real-time heterodyne interferometer". In that work he used an RTL-SDR as a data acquisition tool for an optoelectronic front end sensor (opto = visual light). This allowed him to translate optical data into an RF signal, which could be received by the RTL-SDR, and then easily processed in a PC.

In his latest work Lucas has published a paper titled "Software Defined Optoelectronics: Space and Frequency Diversity in Heterodyne Interferometry" in the IEEE Sensors Journal. Note that the paper is behind an IEEE paywall, but Lucas notes that if you're interested in discussing his work that you can contact him at [email protected] The research is similar to the work published in January, but uses a LimeSDR which can take advantage of TX capabilities. Lucas writes:

In this work, a general architecture for the implementation of software-defined optoelectronic systems (SDOs) is described. This concept harnesses the flexibility of software-defined hardware (SDH) to implement optoelectronic systems which can be configured to adapt to multiple high speed optical engineering applications. As an application example, a software-defined optical interferometer (SDOI) using the LimeSDR platform is built. The system is tested by performing high speed optical detection of laser-induced photoacoustic signals in a concentrated dye solution. Using software modifications only, conventional single carrier and also multicarrier heterodyne techniques with space and frequency diversity are performed.

A main difference with the other article described in this post, is that we could also use the transmission path of the LimeSDR to perform many modulation waveforms of the electromagnetic fields which will interfere, to provide a noticeable performance improvement in single-shot interferometric measurements.

PC: Programmable controller, SDH: Software-defined hardware platform,  E/O: Electrical-Optical block, O/E: Optical-Electrical block, OS: Optical System.
PC: Programmable
controller, SDH: Software-defined hardware platform, E/O: Electrical-Optical block, O/E:
Optical-Electrical block, OS: Optical System.
A Software Defined Optical Interferometer
A Software Defined Optical Interferometer

Hackaday’s LimeSDR Mini Review

Over on Hackaday author Jenny List has today posted a review of the LimeSDR Mini. The LimeSDR Mini is a US$139 TX/RX capable SDR that was successfully crowd funded and has recently begun shipping to initial backers. In the review Jenny goes over the specs and differences between the Mini and standard LimeSDR. She then goes on to test it in GQRX, receiving a DAB digital radio signal, and creating a simple replay attack and FM transmitter in GNU Radio.

If you're interested in the differences between an RTL-SDR and a slightly higher level yet still budget friendly SDR then this review is a good overview. If you are interested, we also did a brief unboxing and initial thoughts review of the LimeSDR Mini which is available here.

The LimeSDR Mini
The LimeSDR Mini