Over on GitHub, John Stockdale has released ADS-B Scope – T-Display-P4, a portable open source 1090 MHz ADS-B firmware for the LILYGO T-Display-P4, which is a smartphone-shaped handheld microcontroller with a 4" touchscreen, GPS, SD card, SX1262 LoRa, and a USB 2.0 host port, built around the dual-core 360 MHz RISC-V ESP32-P4.

The most interesting bit is that John has written a custom USB host driver that allows an RTL-SDR to plug directly into the T-Display-P4. Neither a Pi nor a laptop is needed in the chain. The driver supports the Blog V4/V3 with software bias-tee control and Mode-S demodulation (adapted from dump1090), which runs in real time alongside an on-device aircraft table and radar scope (range rings, trails, helicopter silhouettes). The firmware also implements adaptive gain control, a 587K-record OpenSky aircraft database cached in PSRAM, SD card CSV logging, USB hot-plug, OTA updates, MQTT telemetry, and a WebSerial companion app at adsb-scope.offx1.com with live map, 3D view, CSV replay, and firmware flashing.

In addition to all that, the firmware also runs a Meshtastic-compatible mesh radio on the SX1262 (with PKI DM decryption and MQTT gateway forwarding) and an MP3 player through the onboard ES8311 DAC. John reports ~30 nm range from Oakland, CA on a 7" telescopic antenna, decoding 15–30 messages per second with 12–30+ aircraft tracked.