Digilent 1x1 USB Software-Defined Radio Platform - Review

Table of contents

RoadTest: Digilent 1x1 USB Software-Defined Radio Platform

Author: Attila Tőkés

Creation date:

Evaluation Type: Test Equipment

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: HackRF One, LimeSDR

What were the biggest problems encountered?: some GNU Radio bugs

Detailed Review:

This is the final part of my RoadTest review of the Ettus USRP B205mini-i Software Defined Radio platform: Digilent 1x1 USB Software-Defined Radio Platform


You can find the previous 2 x blog posts here:

Ettus USRP B205mini-i RoadTest | Getting Started

Ettus USRP B205mini-i RoadTest | Experiments



1. Introduction


The USRP B205mini-i is a Software Defined Radio (SDR) device designed by Ettus Research, a subsidiary of National Instruments.


In terms of specification the B205mini-i features:

  • a Frequency range: 70 MHz – 6 GHz
  • up to 56 MHz of instantaneous Bandwidth
  • Full Duplex operation
  • an user programmable Xilinx Spartan-6 XC6SLX150 FPGA
  • USB 3.0 connectivity

(more on the specs later...)


In terms of packaging the B205mini-i comes in a pretty generic NI labeled card box. The product it's clearly not marketed for a huge audience image. The board itself is packaged in a good amount of ESD protection materials:

{gallery} Packaging


Generic National Instruments box


Accessories: USB 3.0 Type-A to Micro-B Cable, Safety and Getting Started Instructions


The USRP: B205mini-i: after the anti-static packaging was removed


As accessories we get an USB 3.0 Type-A to Micro-B Cable cable and some Safety and Getting Started instructions. What I missed here is some kind of low cost antenna, that would allow newcomers to SDR to get started without having to get an antenna separately. I may also 3D print some kind of enclosure for it, as just he bare PCB seems a bit fragile.


On the software side, installing the GNU Radio and the USRP drivers was pretty simple and straight forward.


As a first test I created a simple FM Radio Receiver app, with a hooked up a generic 48 to 860 MHz antenna hooked up to the B205mini-i:


This is how it worked:


2. Experiments


In the second part of my road test consisted in a number of Experiments in which I looked into different wireless technologies working in the unlicensed spectrum. The experiments were carried out on both the USRP B205mini-i and as well on the HackRF One.


In the 1st experiment I tried to create an GNU Radio application that can be used to inspect which are the WiFi channels actively used in our area. The app has two versions, one for the 2.45 GHz and 5 GHz WiFI channels:


{gallery} WiFi Channels


B205mini-i with 2.4 / 5 GHz antenna


WiFi Channels GNU Radio app, 2.4 GHz, B205mini-i


2.4 GHZ WiFi Channels on the USRP B205mini-i


WiFi Channels GNU Radio app, 2.4 GHz, HackRF One



2.4 GHZ WiFi Channels on the HackRF One


WiFi Channels GNU Radio app, 5 GHz, B205mini-i


5 GHZ WiFi Channels on the USRP B205mini-i


WiFi Channels GNU Radio app, 5 GHz, HackRF One


5 GHZ WiFi Channels on the HackRF One


As a 2nd experiment I took a look in a tool that can be used to capture Bluetooth Lowe Energy (BLE) communication. The tool uses GNU Radio along with a Python script to capture, decode and dump BLE packets into a PCAP file. The resulting PCAP file then can be inspected using software like Wireshark:

{gallery} Bluetooth Low Energy (BLE) Scanner


GNU Radio Pipeline, HackRF One Version


GNU Radio Pipeline, USRP B205mini-i version


BLE Packets in WireShark


In the 3rd experiment I attempted reverse engineer a remote control of a retractable sun shade working on 433 MHz. First I used GNU Radio to capture transmissions into a WAV file. Next I used Audiacity to inspect the captured RF data, and created a Python script to decode the message packets.

{gallery} Random 433 MHz Remote


Remote Control for Retractable Sun Shade


Remote Control for Retractable Sun Shade, back side



GNU Radio Pipeline, B205mini-i



GNU Radio Pipeline, HackRF One



RF data in Audacity


RF data in Audacity, zoom in


Decoded message packets


Message Structure


Open, Close and Stop messages


For the last experiment I created a simple GNU Radio application to demonstrate the full-duplex transmit / receive capability of the USRP B205mini-i. The application load an audio signal from a WAV file and transmits on the RX / TX antenna using narrow-band FM modulation. The transmitted signal is picked up by and RX2 antenna, the audio signal is decoded and played back on the speakers:


The source code for the experiments can be found in the following GitHub repository:



3. USRP B205mini-i vs. HackRF One


The Ettus Research USRP B205mini-i and the Great Scott Gadget HackRF One are both SDR devices with somewhat similar capabilities, but also some differences. In this section I will try to compare the two devices, based on the experience gained with carrying out experiments with the two devices.


In terms of specifications the USRP B205mini-i and the HackRF One compares as follows:


USRP B205mini-i

HackRF One

Frequency Range70 MHz - 6 GHz30 MHz - 6 GHz
Bandwidth56 MHz20 MHz

Sample size / rate


12 bits / 61.44 Msps

8 bits @ 20 Msps

DuplexFull DuplexHalf Duplex
Programmable Logic Device


Xilinx Spartan-6 XC6SLX150

(147K logic cells, 1,355 KB RAM, 180 DSP slices, etc.)


Xilinx XC2C64A-7VQG100C

(4 logic block, 64 macro-cells, 1500 gates)


USB 3.0

(5 Gbps)

USB 2.0 High Speed

(480 Mbps)

Is it Open Source?firmware (fpga) + driverhardware + firmware (cpld)+ driver
Cost~ 800 USD~150-300 USD


The usable frequency range (30/70 to 6 GHz) with the two products is basically the same. Both of them cover the full spectrum where usual RF devices work.


The instantaneous bandwidth of the is USRP B205mini-i is much higher at 56 MHz, compared to the 20 MHz bandwidth of the HackRF One. The B205mini-i can listen in a wider section of the RF Spectrum. As we have seen in the WiFi Channels experiment, the B205mini-i was able to cover the 100 MHz spectrum in 2 x 50 MHz steps, while the HackRF One needed 5 x 20 MHz steps. More bandwidth also offers more flexibility in on what RF protocols can be implemented.


The ADC and DAC are also better in the USRP B205mini-i higher sample rate, which is somewhat needed because of the wider bandwidth, and higher resolution (12 bit vs 8 bit).


The last major difference between the two devices is that the B205mini-i offers Full-Duplex communication, while the HackRF One can do one Half-Duplex. This means the B205mini-i can transmit and receive effectively at the same time, while the HackRF One needs constantly switch between transmit and receive modes to do bi-directional communication.


In terms of programmability the B205mini-i uses and FPGA, while the HackRF One uses a CPLD. The FPGA used in the B205mini-i offers a lot more potential processing power, which could be useful in case we want to implement RF application with custom hardware processing.


On the software side the B205mini-i seems to have better better drivers on Linux, although I found the firmware loading a bit slow (~1 min). As Ettus Research is major contributor to GNU Radio, the compatibility with the B205mini-i is excellent. On the other hand the HackRF One is widely used in the hobby community, which means there are lot of open-source projects / tools readily usable with the HackRF One.


The USRP B205mini-i is priced at ~ 800 USD, which is significantly higher then the ~ 300 USD price of the original HackRF One. As the HackRF One is fully open source, including the hardware design, other manufacturers can produce their own version of the device. HackRF One clones are available on AliExpress / Ebay for about ~150 USD.


4. Conclusions


The USRP B205mini-i turns out to be a pretty powerful SDR device. In terms of performance is a significant improvement over my HackRF One.


The product generally performed well. The only minor downsides I found was the lack of an enclosure and antenna, an the somewhat slow firmware loading.


Finally, I would like to thank Element14 and Ettus Research for offering me this device! Surely, it will be an useful tool in many of my future projects.


Hope you enjoyed this Road Test! image