RASDR Startup Guide - myriadrf/RASDR GitHub Wiki

RASDR2 Quick Start Guide

Instructions for installing and using RASDR2 Devices. Please read all the way through once before beginning.

Drivers

The device driver for Windows machines is available on the CD shipped with the unit in the driver/ folder. You can also download the driver files from the distribution website. The procedure to install the driver is as follows:

  1. From the CD, double click the RASDR-authority.cer file, and press 'Install Certificate'.
  2. Make sure that you install the certificate into the 'Trusted Root Certification Store'.
  3. Close the window and re-open the RASDR-authority.cer file after you have installed it to make sure that the certificate is trusted for 'all issuance policies' and 'all application policies' before you connect the RASDR device to your computer.
  4. Ensure the switch on the RASDR device is set to RUN (down).
  5. Connect the RASDR device via the supplied USB3 cable to a USB2 or USB3 port on the computer.
  6. In the new device dialog, choose your CD drive (or the location of where you downloaded the driver files) and tick search all subfolders.
  7. The device should be accepted by the OS and be listed as a RASDR Radio Astronomy SDR Rx Interface

If something goes wrong (such as Windows saying that the driver does not match your operating system), please try again, only this time browsing to the specific folder for your operating system, and 32-bit (x86/) or 64-bit (x64/) under the drivers/os/type/.

If Windows does not bring up a new hardware dialog at all, then please start the Device Manager with an Administrator privledge, browse to the DigiRED_RX device and press the 'Update Driver' button. In the dialog box, use the 'Choose location to install driver...' and select the CD or the location where you downloaded the driver files.

Software

The primary software for using RASDR is RASDRproc.exe which is found on the CD in the RASDRproc/ folder. You can also download software from the distribution website. Please copy the software from the CD to your local hard disk or USB disk before using it. The software writes log, data and configuration files into the folder that it is started from, so it is important to execute the software from a writable location on your computer.

  • RASDRproc
    • This is the program that can configure and calibrate the RASDR receiver. Please run this program first after you connect a RASDR device to your computer.
    • Once you have defined the receiver parameters, there are more options available to you to gain access to the streaming data coming from the device.
    • The program displays time-series data, spectrum data and time-averaged total power data as graphs on the main page.
    • There are options for configuring the receiver, and for writing time-averaged power and spectral data to files on disk for post-processing or analysis.
    • The source code for the program is available on the github repository [1].
  • plotcsv
    • This is a python script that can post-process spectrum files that are produced by RASDproc (and versions of RASDRviewer v1.2.2 and earlier).
    • It is distributed as a portable program with all of its dependencies packaged together (which is why it is 27MB large).
    • It is a command-line driven program
    • There is a file go.bat in the program folder that you can use to make using the program more convenient
    • If you do not have python, please edit the 'go.bat' script to say @set PLOTCSV=plotcsv.exe
    • An example spectrum file is provided along with the program and its support files.
    • The source code to the program is the python script plotcsv.py itself.
  • RASDRstreamer
    • This program can stream data from the RASDR device once it has been configured by RASDRproc at least once.
    • The program can co-exist with RASDRproc
    • RASDRstreamer can stream all data it receives to a disk file
    • The file will always be created in the same folder as the program; so if you want to stream to a special disk (such as an SSD or a RAID array you have), just copy the RASDRstreamer program folder (and the 3 .dll files that it needs) to the disk you want to write to.
    • The source code for the program is available on the github repository [2].
  • raw2iq
    • This program can interpret/convert raw data files that were generated by RASDRstreamer
    • The program can write out 16-bit signed I and Q samples to binary or ASCII files
    • raw data files contain control bits that must be stripped out and this program shows how to do it
    • The source code for the program is available on the github repository [3].

You may also be interested in a program called fftw-calc that can help to determine if your computer is capable of handing the data processing required for the combination of { sample rate, FFT frame size } that you would like to use for your observations.

Hardware

To perform observations you will need at least 3 things:

  1. An antenna with some amount of gain at the frequency you want to observe
  2. A RASDR2 unit
  3. A computer with a USB interface that runs Windows

The RASDR2 unit operates on the power from your computer's USB interface and it draws up to 580mA when running over USB3 at 25 Msps. Make sure that your USB port can provide the necessary power. Some laptops have a certain "high-power" USB port labeled with a small lightning-bolt. Your laptop may not be capable of supplying the necessary current and if so, will hopefully tell you when you plug the device in (RASDR firmware reports that it requires 750mA to operate under USB3). The RASDR developers assume no responsibility for any damage the RASDR2 hardware may cause to customer equipment.

Operation

The Society of Amateur Radio Astronomers have produced an excellent beginners reference [4] to radio astronomy. It is well worth reading this material if you have not already done so.

The RASDR2 receiver is suitable for use as an antenna interface in the UHF band. A good strategy to making useful observations is to do the following:

  1. Determine the type of observation you wish to make and what parameters you will use
  • Bandwidth
    1. H1 is inherently a narrowband phenomenon - choose a 2MSPS sample rate and 1.5Mhz or 1.75MHz filter bandwidth
    2. Continuum is inherently a wideband phenomenon - choose the widest possible bandwidth
    3. Your choice of bandwidth typically determines your sample rate (but see below)
  • FFT size
    1. The samples/frame and the sample rate determine what the frequency resolution of the spectrum output will be
    2. Frequency Resolution = Sample Rate / FFT size
    3. for H1, this translates into what doppler shift you are able to resolve with your equipment
    4. rule of thumb is to allow for about 5KHz per frequency point
  • Gain
    1. You will need to determine the best settings for RASDR (receiver) and system gain
    2. If you have a strong low noise pre-amplifier you may need to bypass the LNA gain on the RASDR to reduce intermodulation due to components between the antenna and the RASDR
  • Filtering
    1. If your antenna is wideband, you may need some amount of filtering in front of the RASDR receiver to prevent signals from getting in and creating intermodulation harmonics in the RF system.
    2. If you have a filter then you must have some amount of gain in front of the filter to prevent birdies.
  1. Construct your antenna and front end system.
  2. Calibrate your receiver before starting your observation.
  • Tune the RASDR to the desired frequency, set the gain parameters
  • Disconnect your antenna and connect a load to your front end
  • Use the IQ adjustment in the RASDRproc menu Performance Parameters->Tuning Parameters to balance the I/Q
  • Define your reference level by pressing the SetPwrRef button

Troubleshooting

When the RASDR2 device is operating normally, an LED will blink at approximately 1 Hz. If you look into the ACT window, you will see two LEDs always lit, and behind these there will be LEDs that blink. The right-most LED normally blinks at 1Hz. If you see something else, it means that the RASDR device did not successfully connect to the driver. Try a different USB port or try a different cable.

If you see no LEDs at all, then the connection between your computer and the RASDR device is not being made. This can happen if the USB connector inside the case has failed. In these cases, please return the RASDR unit for repair.

If the RASDRproc program has problems establishing the connection, try staring the CyControl program on the CD at CyControl\bin\CyControl.exe. This program can report what the OS thinks it sees when you connect a RASDR device. If you see 'Cypress USB Bootloader`, double-check the PROG/RUN switch to make sure it is in the RUN (down) position.

If you cannot get it to work, please contact Bogdan Vacaliuc at bvacaliuc at gmail dot com.

Sources of Support

It is recommended that the user become a member of SARA:

www.radio-astronomy.org

and joining the RASDR Users Group:

https://groups.io/g/RASDR

The RASDR User Guide is provided on the CD, but it can also be downloaded [5]. It contains detailed information on updating firmware, details on command and responses used by the firmware to setup and control the receiver as well as a variety of way that a radio telescope may be constructed with the RASDR device.

References

[1] https://github.com/myriadrf/RASDR/tree/master/host/RASDRproc

[2] https://github.com/myriadrf/RASDR/tree/master/host/RASDRstreamer

[3] https://github.com/myriadrf/RASDR/tree/master/host/raw2iq

[4] http://www.radio-astronomy.org/pdf/sara-beginner-booklet.pdf

[5] http://rasdr.org/release/1.2.4/RASDR-Users-manual-v1.7.5.pdf