RTL-SDR on iPad without jailbreak opens to TestFlight beta testers

An RTL-SDR dongle plugged straight into an iPad, with no jailbreak and no second computer, is now something anyone with the right tablet can try. Developer Arved, DK5AV/M0KDS, has opened a public TestFlight beta of his iPad driver and host app after receiving distribution entitlement from Apple, RTL-SDR.com reports.

Until this work, iOS devices could not drive an RTL-SDR directly. The usual workaround was to run the dongle on another machine and stream it to the phone or tablet over the network with rtl_tcp, a small server that sends raw receiver samples to client software. Arved says he wants feedback from beta testers before submitting the app to the App Store.

The biggest new feature is an rtl_tcp server that runs on the iPad itself. That means existing iOS apps that already speak rtl_tcp, such as CoronaSDR and VibeSDR, can use a locally connected dongle through this driver. The host app also includes a diagnostics view to confirm the driver is talking to the radio correctly, and a built-in broadcast FM receiver with stereo and RDS.

On the driver side, Arved has added support for the V4 dongle, which did not work in the earlier version. Tuners in the FCxxxx family have been dropped for now because of App Store conflicts with the GPL license, and the driver is now built on the open source GNU Radio driver rather than librtlsdr for the same licensing reason. He says he may be able to bring the other tuners back later. The driver remains open source, and its API is published as a header so future apps can talk to it directly.

There is one hardware limit: the beta works only on iPads with an Apple M-series chip. iPhones, which use A-series chips, are not compatible. The TestFlight invitation is at https://testflight.apple.com/join/jUDtSBmb.