iotSDR Crowdfunding: An SDR Devboard for Designing Custom IoT Protocols and Gateways

A new SDR has recently launched on the CrowdSupply crowdfunding platform. This one is called "iotSDR" and is designed to be a software defined radio to help developers and enthusiasts design custom Internet of Things (IoT) algorithms and protocols.

It has a 2-channel AT86RF215 transceiver chip which is capable of tuning to all major IoT frequencies as well as a 13-bit ADC with sample rate of up to 4 MSPS. In addition is a MAX2769B chip which is used for the GNSS reception of GPS, GLONASS, Galileo and Beidou positioning satellites. An onboard ZYNQ XC7Z010 / XC7Z020 FPGA can be used for any hardware computing required.

iotSDR currently costs US$399 for the Zync XC7Z010 FPGA version, and US$599 for the Zynq XC7Z020 FPGA version. At the time of this post there are 37 days left in the campaign.

Embedding SDR in IoT

iotSDR provides a platform that allows SDR developers and enthusiasts to design innovative algorithms and cutting-edge products. While wide-band SDRs are more versatile, narrow-band transceivers perform better for many IoT-related applications. Accordingly, iotSDR hosts two narrow-band Microchip AT86RF215 transceivers that provide their own base-band cores and have the ability to handle their own I/Q signal streaming. The result is an extremely powerful tool for anyone who is looking to simplify the task of developing, testing, and deploying high-complexity frameworks.

A Powerful FPGA and a GNSS Chip to Round It Out

iotSDR’s Microchip transceivers are backed by a Zynq SoC—which provides an FPGA and a processing system in a single package—as well as a MAX2769 GNSS chip capable of streaming live signal records. That GNSS chip can be used for custom GPS, Galileo, BieDou, and GLONASS receiver development, and is perfect for projects in the location-based services (LBS) domain such as those related to navigation and surveying.

Use Existing Software, Design a Protocol, or Build a Gateway

You can drive the hardware described above using a wide variety of popular open source software, including the Xilinx PYNQ Python framework, Jupyter Notebooks, and GNU Radio.

And if your work is further down the stack, don’t worry. iotSDR still has you covered. If you want to design and implement a physical layer IoT protocol, for example—a protocol like LoRa, SigFox, WightLess, Bluetooth, BLE, 802.15.4, ZigBee, or something of your own design—this board is for you. It’s also a great place to start if you want to build a custom IoT gateway along the lines of The Things NetworkLPWAN, or Google’s Thread.

Radio has long been a pillar of modernization and technology, and this remains true in the era of software-defined radio. The Internet of Things, in particular, stands to benefit from the latest advancements in SDR technology. With iotSDR, you can be part of the community that makes that happen.

Features & Specifications

  • RF Transceiver: 2x Microchip/Atmel AT86RF215
    • European band: 863-870 MHz / 870-876 MHz / 915-921 MHz
    • Chinese band: 470-510 MHz / 779-787 MHz
    • North American band: 902-928 MHz
    • Korean band: 917-923.5 MHz
    • Japanese band: 920-928 MHz
    • World-wide ISM band: 2400-2483.5 MHz
  • GNSS Receiver: Maxim MAX2769B supporting GPS, GLONASS, Galileo, and BieDou
  • SoC: Two options available
    • Xilinx ZYNQ XC7Z010-1CLG400C
      • Dual-core ARM Cortex-A9 MPCore
      • 256 kb on-chip memory
      • DDR3 support
      • 28,000 logic cells
      • 17,600 LUTs
      • 2.1 Mb block RAM
      • 80 DSP slices
      • 2x UART, 2x CAN 2.0 B, 2x I²C, 2x SPI, 4x 32-bit GPIO
      • FPGA configuration via JTAG
    • Xilinx ZYNQ XC7Z020-1CLG400C
      • Dual-core ARM Cortex-A9 MPCore
      • 256 kb on-chip memory
      • DDR3 support
      • 85,000 logic cells
      • 53,200 LUTs
      • 4.9 Mb block RAM
      • 220 DSP slices
      • 2x UART, 2x CAN 2.0 B, 2x I²C, 2x SPI, 4x 32-bit GPIO
      • FPGA configuration via JTAG
  • EEPROM Memory: 1x Microchip AT24MAC602 for RF transceiver MCU firmware and data
  • Flash Memory: 1x QSPI 128 Mb flash memory for firmware
  • RAM: 512 MB DDR3
  • SD Card: Micro SD card slot
  • General User Inputs/Outputs:
    • 2x 8-bit PL (Programmable Logic) interfaces
    • 1x 8-bit PS (Programmable Subsystems) interface
  • Connectivity:
    • 1x Gigabit Ethernet
    • USB 2.0 High Speed (Microchip USB3310)
    • USB 2.0 Full Speed (Silicon Labs CP2104)
    • 2x SMA RF connector for Low Frequency IoT band
    • 2x SMA RF connector for 2.4 GHz band
    • 1x SMA connector for GNSS receiver
    • FPGA JTAG connector for external JTAG programmer/debugger
  • Clock System:
    • Single clock source for both RF frontends
    • Separate clock for GNSS receiver
  • Board Dimensions: 76.2 mm x 101.6 mm
The iotSDR

Analyzing Lightning Discharges with an RTL-SDR and the Sage Network

Sage is a project working on creating geographically distributed sensor systems including cameras, microphones, weather and air quality stations in order to benefit the work of scientists. Recently on their GitHub they have uploaded a Jupyter Notebook showing how they have used an RTL-SDR V3 on a Linux Laptop to analyze lightning discharges. When lightning strikes, it creates a broadband RF pulse generally across the lower frequencies. This is how live lightning maps like Blitzortung work.

In their example Sage use a dipole antenna and analysis frequency of 30 MHz. The notebook doesn't offer much additional information, but provides Python Numpy and Scipy code which can be used to detect and plot the lightning pulses.

Graphing Lightning Pulses for the Sage Network

RSGB Talk: How To Check and Report VDSL RFI with an SDR in the UK

Back in April we posted a video from Tech Minds where he showed us how to use special software combined with an SDRplay RSPdx to detect and report VDSL interference on the HF bands. VDSL or Very High Speed Digital Subscriber Line is an internet connection technology that runs over old copper phone wires allowing for a fast broadband connection. The frequencies used by VDSL are between 25 kHz to 12 MHz, and for VDSL2 up to 30 MHz. Unfortunately the frequencies used can result in high amounts of radio interference from RFI radiating from the copper phone lines which is a major problem for HF amateurs and short wave listeners.

Recently John Rogers (M0JAV) presented a talk via the UK amateur radio organization RSGB. In the talk he explains how VDSL works, why it causes RFI and how to check for VDSL RFI using an SDR and the Lelantos software. He also shows how he drove around with a magnetic loop antenna looking for VDSL RFI sources in his neighbourhood. He then goes on to call out for more volunteers in the UK to submit RFI reports to Ofcom as they responded that they won't do anything about the interference unless there are more complaints. 

The RSGB EMC Committee (EMCC) has been investigating VDSL interference since 2014. As the number of installations has risen to over 30M the interference level at amateur radio stations has also increased. The majority of radio amateurs are now impacted by this problem.

In the May 2020 RadCom we outlined how to detect and estimate the level of interference. This can be done by inspection of an SDR spectrum display or by taking a recording and then using a SW package—developed by Martin Sach of the EMCC—which identifies the VDSL signature in the recording and shows how many different VDSL lines are causing the problem and what their relative strengths are.

This talk demonstrates what to look for and how to use the tools to find out if you have a problem yourselves. We hope this will help you respond to our call for action and complain to Ofcom about the level of RFI you are subjected to.

John Rogers, M0JAV
Chair EMCC

RSGB Tonight @ 8 - How to check for VDSL RFI with John Rogers, M0JAV

The Silphase R1 SDR Receiver

Thanks to Thomas' SWLing Blog for bringing to attention the Silphase R1 SDR receiver. This is an upcoming high performance HF SDR receiver being manufactured in the EU by a Polish company called Silphase. The R1 appears to be targeting premium SWLer customers with a price of US$1199. However, they note that by the end of 2020 they will have a 25W transceiver option, and later a 100W transceiver option. The SDR is currently available for preorder only and the sign up form can be found at the bottom of their website.

The Silphase R1 comes with a 5" touch screen that shows a spectrum display, has dual VFO's, four speakers and a metal alloy enclosure. It also comes with a built in telescopic antenna, but external antennas can be connected with the F connector. The tuning range is just the HF bands from 0.1 - 30 MHz and the ADC resolution is 16 bits.

Rendering of the upcoming Silphase R1 HF SWLing SDR

SignalID: Shazam Style Automatic Signal Identification for Android

SignalID is a new Android app available on the Google Play store which offers Shazam-like radio signal identification. Just like Shazam does for music, you simply tune to an unknown signal with your SDR, play the raw audio, and let the app listen to it for five seconds. It then computes an audio fingerprint and checks to see if it knows what the signal is. 

We tested the app but unfortunately we were unable to get it to detect any signals. Please write in the comments if you have success. As it uses audio fingerprinting, the app is probably highly dependant on choosing the correct demodulator (AM/FM/SSB etc), and also the tuning and signal quality. We note that most of the signal sources seem to come from our sister site the Signal ID Wiki. Searching through the wiki is a good alternative if automated solutions fail.

However the the app is new and we expect improvements and more signals to be added in the future. Currently the following signals can be recognized: 

- RTTY (Commercial 85Hz, 170Hz, 450Hz, 850Hz, Amateur 170Hz)
- PactorI (Standard, FSP, FEC, SELCALL)
- ASCII (170Hz)
- ALIS
- Codan8580 (200Hz, 250Hz)
- CIS36_50
- CIS40_5
- CIS50_50
- STANAG 4285 (GEN, SYS3000 FEC, 8PSK, TFC, IDLE, SYS3000)
- FT4

- FT8
- WEFAX (120, 240)
- 2G ALE
- 3G ALE
- CHIP64
- APRS (Burst)
- ATIS
- Tetrapol
- POCSAG
- FLEX (2FSK)
- PSK (31, 63, 125, 250, 500)

We note that this app reminds us of a Python based signal identification app for the PC called "audio_recognition_system" which we posted about earlier this year.

SignalID: Shazam-like audio based signal identification for Android.
SignalID - Demonstration

Frugal Radio: SDR Guide Ep 4 – Antenna Basics for SDR Beginners

In this episode of Frugal Radio's series of SDR beginners guide videos he discusses some antenna basics. He shows the most common types of antennas, provides several tips to help improve reception, and shows how to properly tune antennas using online calculators.

Near the end of the video he shows our multipurpose dipole antenna kit and shows how to adjust the telescopic elements for best reception. He demonstrates that simply extending the elements to the maximum length does not result in the best tuning, rather you need to tune the element length for the frequency being received to get the best results.

2020 SDR Guide Ep 4 : Antenna Basics for SDR Beginners inc RTL-SDR / Nooelec NESDR SMArt bundle

TechMinds: Building a 3D Printed 2.4 GHz Dual Feed Helix for QO-100

The Bullseye LNB that we have in our store is great for receiving the QO-100 amateur geostationary radio satellite which is available in some parts of the world. However it cannot be used to transmit to the satellite. Over on his YouTube channel Tech Minds shows us how to build a transmit helix antenna that connects to the Bullseye or other suitable LNB, resulting in a dual feed antenna.

The antenna that was built is based on DO8PAT's "Ice Cone Feed" design. The design requires some 3D printed parts for the mount and housing, as well as a copper wire helix, metal reflector and copper matching strip. The Bullseye fits onto the back of the helix mount. Once mounted on a dish Tech Minds shows that he was able to make contact with a friend via the QO-100 satellite with good signal strength.

2.4 GHz Dual Feed Helix Antenna For QO100

Standalone Windows FengYun-3 & MetOp HRPT Weather Satellite Decoder

Back in June we posted about Alan (@aang254)'s work on porting the GNU Radio gr-hrpt decoder over to GNU Radio 3.8. More recently Alan wrote in and wanted to share the news that he has recently released standalone Windows decoders for the MetOp and FengYun-3 weather satellites.

MetOp and FengYun-3 are both polar orbiting satellites that beam back high resolution weather satellite images. Unlike the NOAA polar orbiting satellites which transmit both the easy to receive APT and more advanced HRPT signal, these only transmit a HRPT signal at ~1.70 GHz, so a satellite dish and motorized tracking mount (or hand tracked) is required. You will also need an SDR capable of receiving over 3 MHz bandwidth such as an Airspy Mini or R2. Alan writes:

I recently got FengYun decoding working after the release of my MetOp decoder a while ago. Since gr-hrpt wasn't usable for Windows user without some major hassle, I made some standalone decoders (Windows builds included in the repo) for both MetOp and FengYun.

Decoding is done by first demodulating with the included flowcharts or @petermeteor's, then processed through the decoder which does Viterbi / Differential decoding. The output then needs to be deframed by MetFy3x or any other software that can do so.

https://github.com/altillimity/Satellite-Decoders

A few images!

https://twitter.com/SamuelArmstro18/status/1285647473881513989
https://twitter.com/ZSztanga/status/1285277472284708865
https://www.reddit.com/r/amateursatellites/comments/hwhb7q/my_longest_fy3b_image_yet_i_got_up_at_430_in_the/
https://twitter.com/HA6NAB_Tomi/status/1285300023350222848
https://twitter.com/ub1qbj/status/1286734822820532224/photo/1

You can learn more about these satellites on USA-Satcom's Cyberspectrum talk and slides.