GNU Radio Error Message “unable to scan ip19”
That error message — “unable to scan ip19” — isn’t a standard GNU Radio error on its own. It usually comes from an underlying hardware driver or device source block that GNU Radio is trying to access. Let me break it down:
• ip19 looks like a shorthand for a device index (IP address, unit number, or driver identifier).
• In SDRplay’s API (e.g., SoapySDR, gr-osmosdr, or sdrplay_source block), devices are enumerated with identifiers. If the library can’t find the device or access it, GNU Radio might throw “unable to scan ipXX”.
• Sometimes this happens if:
• The SDR device isn’t plugged in or powered.
• The wrong driver is being called (e.g., osmosdr vs. SoapySDR vs. native API).
• Permissions aren’t set (Linux often needs a udev rule for SDRs).
• The device index is off — maybe GNU Radio is trying to open ip19 when only ip0 exists.
✅ Steps to troubleshoot:
IF YOU ARE ON LINUX:
• Run
SoapySDRUtil –find
or
sdrplay_apiService
to check which devices are visible.
• If using osmosdr source in GRC, try leaving the “Device Arguments” field blank first — it will auto-detect.
• If you see multiple SDRplay tuners, make sure you specify the correct one (e.g., soapy=0, soapy=1, or rspduo_mode=dual).
• Check that the SDRplay API service is running:
systemctl status sdrplay
• If permissions are the issue, run GNU Radio once as sudo. If it works, you’ll need to fix the udev rules so you don’t need root.
WINDOWS 11:
If you are on Windows 11, using GNU Radio + RTL-SDR v4 (not the RSPduo right now).
The error “unable to scan ip19” isn’t coming from GNU Radio itself, but rather from the RTL-SDR driver layer (librtlsdr). On Windows, this usually points to a driver mismatch or wrong device index.
Here’s what’s likely going on and how to fix it:
🔎 Why this happens
• RTL-SDR v4 requires a patched driver. The older librtlsdr bundled with many GNU Radio builds doesn’t know about the v4, so it fails with odd errors (like ip19).
• Device index mismatch: GNU Radio’s osmocom Source block tries to scan for rtl=0,1,2…, but if the driver can’t see the v4 correctly, it throws scanning errors.
✅ Step-by-step fix
• Check if Windows sees your dongle
• Open Device Manager → Universal Serial Bus devices.
• You should see something like “RTL2832U” or “RTL-SDR Blog V4”.
• Install Zadig driver for v4
• Download Zadig.
• Plug in your RTL-SDR v4.
• In Zadig, select the device (Bulk-In, Interface 0).
• Install WinUSB driver.
(If you already did this for an older dongle, repeat — the v4 enumerates differently.)
• Update to librtlsdr with v4 support
• The stock GNU Radio build for Windows may not support RTL-SDR v4.
• Download the community-patched Windows binaries from the RTL-SDR Blog.
• Replace the old rtlsdr.dll in your GNU Radio installation (gnuradio\bin or gnuradio\lib) with the updated one.
• Test outside GNU Radio
• Open a terminal in the folder with your updated DLLs.
• Run:
rtl_test -t
• If it works, you’ll see the tuner type detected (should say RTL-SDR Blog V4).
• Re-run GNU Radio
• In your flowgraph, use the Osmocom Source block.
• Set Device Arguments to:
rtl=0
• Leave other fields (IP, serial) empty.
💡 If you still get the ip19 error after this, it means GNU Radio is still pointing to the old librtlsdr DLL instead of the patched one — I can walk you through checking the search paths and replacing the right file.
Here’s the latest Windows build of the patched librtlsdr / “RTL-SDR Blog” driver / DLL for RTL-SDR V4, and how you can install it so GNU Radio can see it.
🔍 What to download
From the RTL-SDR Blog GitHub:
• Release name: RTL-SDR-BLOG Windows Release V1.3.6 — includes support for RTL-SDR Blog V4 (R828D tuner) (GitHub)
• Files included: Windows DLLs / executables (in “Assets”) that work with V4. (GitHub)
🛠 How to install
• Download the release
Go to the GitHub RTL-SDR-Blog releases page, and download Release V1.3.6 (or the latest available) Assets. (GitHub)
• Extract needed files
From the release ZIP, you’ll have files like rtlsdr.dll, possibly msvcr100.dll, pthreadVC2.dll, etc. (rtl-sdr.com)
• Locate your GNU Radio install’s DLL folder
This is typically under something like C:\Program Files\GNURadio\bin\ or wherever GNU Radio is installed on your Windows system.
• Backup old dll
• Rename the existing librtlsdr.dll (or rtlsdr.dll, depending on name used) to something like librtlsdr_old.dll so you can restore if needed.
• If there are other rtl-sdr DLLs in your PATH or application folder, take note and back them up too.
• Copy new DLLs into place
• Copy rtlsdr.dll (from the V1.3.6 release) into the folder where GNU Radio expects it.
• If GNU Radio expects the name librtlsdr.dll, you may need to rename rtlsdr.dll → librtlsdr.dll after copying.
• Also copy any dependency DLLs (msvcr100.dll, pthreadVC2.dll) into the same folder (if they’re not already present) so the library loads properly. (rtl-sdr.com)
• Install driver (with Zadig)
• Plug in your RTL-SDR V4 dongle.
• Run Zadig → select the RTL-SDR device (check “List All Devices” if needed) → choose WinUSB as the driver.
• Install / replace driver. (This makes sure Windows will let software talk to device properly) (rtl-sdr.com)
• Restart GNU Radio / reboot PC
• To ensure no old library is being held in memory.
• Then test in GNU Radio with e.g. an Osmocom Source block. Use device arguments like rtl=0. Leave other device arguments blank to let autodetect work.