LimeSDR

Software

Driver

The driver must be installed before you can use SDR Console. See: driver installation for latest information.

 

  • Download the Windows drivers as a ZIP file
  • Select Clone or download
  • Select Download ZIP
  • The ZIP file contains the drivers for various versions of Windows.

 

Now follow the instructions on driver installation.

Firmware

Make sure you are using the latest firmware, information is on the wiki: [Link]. Use the LimeSuitGUI program to load new firmware; a very simple process. The LimeSuiteGUI is downloaded here. Firmware info is here.

Source Code (Developer Only)

The Lime support library source code is on GitHub here , the main header file is here. For LimeRFE support the library source code is on GitHub here, the main header file is here. The only project needed is LimeSuite, other projects can be (and should be) ignored.


⚠️ The Cypress EZ-USB FX3 SDK must be installed before the LimeSuite library is built.

Checklist

For the best Lime experience:


✓ Use an external power supply, required voltage is between 6V and 12v.

✓ Always use the latest firmware [ link ]!

✓ Use a powered USB hub - many motherboards cannot supply enough current, especially for the LimeSDR Mini which does not support an external power supply. 

✓ Set the drive level to avoid IMD - See Options .

✓ Keep your hardware cool:

 

  • Add heatsinks to the FPGA and Lime LMS7002M
  • If in a case make sure there's airflow - add a small fan
  • Use low bandwidths, lower bandwidths process less data, the FPGA (big chip) will have less work to do and be cooler

 

Lime Quick Test

An excellent utility from Lime which reports the health of your device: https://wiki.myriadrf.org/LimeQuickTest. Just run this program, it creates a logfile in the current folder, example is here .

HF Support

To use the Lime on frequencies below 30MHz the Lime's LO is set to 30MHz and frequencies below that are "faked" by increasing RF rate, down-sampling it to requested sampling rate and moving it with NCO so it looks like it is at requested LO.


Sample Rate

The minimum sample rate for a HF frequency (in Hz):

Rate = (2 * (30000000 - HF(Hz) - 1))/31 .


⚠️ The sample rate 3MHz supports on all bands from 1.8 MHz to 28 MHz, 750kHz only supports some higher HF bands.

⚠️ For HF the Hermes-Lite 2 is strongly recommended as a high-quality and low-cost solution.

Cooling

If your Lime freezes or becomes unreliable then coolling is recommended. The Keynice Mini USB Clip and Desk Personal Fan is highly recommended, available from many online stores.

This reduced the temperature of a v1.3 Lime Mini (as below) from 40°C to 25°C.

Calibration

About

Calibration reduces a spur in the centre of the display and strong signal images, both for receive and transmit. It is only possible to calibrate the Lime system once it has been started and running for about one second. Calibration values are restored whenever possible.

Radio Panel

The Radio panel (below) has options for RX and TX calibration.

 

  • RX Calibrate is always enabled,
  • TX Calibrate is only enabled while you are transmitting.

 

The ✓ indicates the current calibration is valid, ✗ indicates that calibration is required. When you start a LimeSDR or change frequency previous calibration values will be used if available.

Spur Reduction

⚠️ To remove the spur in the centre of the display increase the Gain to ~25dB or more, decrease the Visual Gain (Vis: Gain) to ~-30dB.

RX Calibrate

When you press RX Calibrate the software will adjust gains in the LimeSuite support software to ensure the calibration succeeds. During calibration the waterfall will normally show higher values while calibration is running.


Note: calibration is part of the Lime support library. When you press RX Calib / TX Calib and the receive gain / transmit drive is too low then an error is displayed. When calibration runs automatically any error is suppressed.

Automatic Calibration

In the ... More options select the time after which receive calibration is automatically started. It is only possible to calibrate the Lime system once it has been started and running for about one second. Calibration values are restored whenever possible.

When calibration runs automatically any error is suppressed.

Diagnostics

Lime Mini - Wrong Data

When starting a stream, sometimes the data is almost right - but isn’t. In the first image there are spurs every ~ 12 kHz apart.
By simply setting the LO frequency again the data is then correct (below). Note: the LO frequency is the radio's centre frequency as shown at the bottom of the console display.
This problem is being actively investigated.

USB Interface

When searching for Lime SDRs the interface (USB 2 / USB 3) is returned. For example:

LimeSDR-USB, media=USB 3.0, module=FX3, serial=0009060B00471621, index=0

When starting the Lime more detailed information is shown in the logfile, for example:

Radio LimeSDR> Device: device name ............: LimeSDR-USB
Radio LimeSDR>         expansion name .........: UNSUPPORTED
Radio LimeSDR>         firmware version .......: 4
Radio LimeSDR>         hardware version .......: 4
Radio LimeSDR>         protocol version .......: 1
Radio LimeSDR>         board serial number ....: x00471621
Radio LimeSDR>         gateware version .......: 2.18
Radio LimeSDR>         gateware target board ..: LimeSDR-USB
Radio LimeSDR>         library version ........: 19.04.1-unknown

No Response

If you do not get any response from the LimeSDR make sure the USB cable is pushed firmly into the board - this may sound obvious, but it has happened!
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