sdrangel/plugins/samplesource/sdrplay

SDRPlay plugin

Introduction

This plugin supports input from SDRPlay devices. SDRPlay is based on the MSi001 and MSi2500 chips from Mirics. The standard API provided by Mirics is closed source moreover it could not be implemented successfully in SDRangel. An open source API libmirisdr-2 has been written by Miroslav Slugen and later amended by Leif Asbrink SM5BSZ. Some enhancements and bug fixes have nade it to libmirisdr-4 in this repository. It is this API that is used to drive the SDRPlay.

SDRPlay has a rather good performance in HF bands due to front end filtering and the MSi001 chip. This sets it apart from the other supported hardware and is an interesting addition to the collection.

Note to Windows users: this plugin uses standard USB interface provided by Zadig (for example). It is not compatible with the drivers from Mirics so you will have to unistall (or you should not install) the Mirics software before you can use this plugin.

Build

As mentioned already the plugin depends on libmirisdr-4. You will have to specify the include and library paths on the cmake command line. Say if you install libmirisdr-4 in /opt/install/libmirisdr you will have to add -DLIBMIRISDR_INCLUDE_DIR=/opt/install/libmirisdr/include -DLIBMIRISDR_LIBRARIES=/opt/install/libmirisdr/lib/libmirisdr.so on the cmake command line.

Interface

1. Common controls

Controls common to all source plugins. See .

2. Local oscillator frequency correction

This is the correction in tenths of ppm steps. This is hardly useful with SDRPlay as it has been found on spot. It appears on many source plugins ans it has been kept as LO accuracy could depend on units.

3. DC and IQ imbalance correction

These are controls common to many source plugins too. IQ imbalance is hardly useful but SDRPlay is affected by DC bias when used at zero IF.

4. Band selection

This selects a frequency range corresponding to the hardware path in the SDRPlay. Bands available are:

• 10 kHz to 12 MHz
• 12 MHz to 30 MHz
• 30 MHz to 50 MHz
• 50 MHz to 120 MHz
• 120 MHz to 250 MHz
• 250 MHz to 380 MHz
• 380 MHz to 1 GHz
• 1 GHz to 2 GHz

5. IF bandwidth

This selects the IF filter. Following bandwidths are available according to MSi001 specs:

• 200 kHz
• 300 kHz
• 600 kHz
• 1536 kHz
• 5000 kHz
• 6000 kHz
• 7000 kHz
• 8000 kHz

6. IF frequency

This select the IF frequency between these values:

• 0 for zero IF
• 450 kHz: you have to set sample rate to 1792 kHz (7) and use decimation (8) with an infradyne position (9)
• 1620 kHz: you have to set sample rate to 6400 kHz (7) and use decimation (8) with an infradyne position (9)
• 2048 kHz: you have to set sample rate to 8192 kHz (7) and use decimation (8) with an infradyne position (9)

7. Sample rate

You have the choice between various sample rates from 1536 to 8192 kHz. Some values have a special destination:

• 1792 kHz: for use with an IF of 450 kHz.
• 6400 kHz: for use with an IF of 1620 kHz.
• 8192 kHz: for use with an IF of 2048 kHz.

8. Decimation

Decimation in powers of two from 1 (no decimation) to 64.

9. Center frequency position

Relative position of center frequency of decimated baseband relative to the original:

• Inf: infradyne i.e. in the lower half of original baseband: to be used with non zero IFs
• Cen: Centered i.e. around the center of the original baseband
• Sup: Supradyne i.e. in the upper half of original baseband

10. Tuner gain mode

Use this radiobuton to select a mode where the gain of LNA (or mixer buffer), mixer and baseband amplifiers is automatically selected depending on the tuner gain index (11). This index is the gain value in dB at nominal gain of all amplifiers. This is not the exact gain at all frequencies because the LNA gain decreases significantly at higher frequencies.

11. Tuner gain setting

The tuner gain index can be set between 0 and 102.

12. Manual gain mode

Use this radiobuton to select a mode where the gain of all amplifiers can be set independently

13. LNA toggle

Toggle button to switch on or off the LNA (bands higher than 50 MHz) or mixer buffer (band lower than 50 MHz). The nominal gain is +24 dB

14. Mixer amplifier toggle

Toggle button to switch on or off the mixer amplifier. The gain of this amplifier is +19 dB

15. Baseband amplifier gain

Baseband amplifier gain from 0 to 59 dB