v1.0.0-rc4

esp32-sdr-trx turns one ESP32-S3 dev board into a software-defined transceiver for 13 cm: an rtl_tcp receiver for SDR++ (1.84 to 2.79 GHz, 250 or 333 ksps, no FPGA) and an
experimental FM/SSB voice transmitter (2320 to 2450 MHz). Built on eSpDR by h0m3us3r.

Install (Linux, Python 3.10+)

Download the wheel and install-linux.sh below, then:

chmod +x install-linux.sh
./install-linux.sh esp32_sdr_trx-*.whl --audio       # --audio: a sound card as a transmit source
espdr-rx                                              # receiver: rtl_tcp server on 127.0.0.1:1234 for SDR++
espdr-tx --accept-licence -f 2350 -m usb -i soundcard # transmitter: read docs/transmitter.md first

The wheel contains the firmware images and the tools load the right one into the board's RAM by themselves. Step by step, including the virtual environment and the
udev rule: docs/install.md. esp32-sdr-trx-rx.bin and esp32-sdr-trx-tx.bin are the bare images,
SHA256SUMS lists everything.

Tested

One board (a generic ESP32-S3-WROOM-1 dev board with two USB-C ports), one Linux host, a PlutoSDR and a HackRF as test equipment. Receiver: 20 to 120 s runs without lost samples at
250 and 333 ksps, SDR++ over the bridge. Transmitter: FM and SSB voice from a WAV file, a pipe and a sound card (20 to 30 s without an underrun), five frequencies over the band,
the carrier stops 0.54 s after the host disappears, crystal correction with --ppm. Measured with the carrier suppressed: unwanted sideband 61 to 63 dB and third-order
intermodulation 33 dB below the wanted tones. All numbers: docs/research/TX-RESEARCH.md.

Read before you transmit

Transmitting takes an amateur radio licence. The firmware only sends in 2320 to 2450 MHz. The power is not calibrated (an estimate: microwatts at the antenna of a plain dev board), harmonics and
spurious emissions were not measured, and the frequency is only as good as the board's crystal (use --ppm). Windows and macOS are untested. Much of the code and the documentation was written
with Claude (Anthropic) as the coding assistant; every number in the documentation was measured.

What's Changed

• espdr-tx: --thermal auto (default), per-board model files, tested on two boards by @jochenhammes in #3

Full Changelog: v1.0.0-rc3...v1.0.0-rc4

v1.0.0-rc3

esp32-sdr-trx turns one ESP32-S3 dev board into a software-defined transceiver for 13 cm: an rtl_tcp receiver for SDR++ (1.84 to 2.79 GHz, 250 or 333 ksps, no FPGA) and an
experimental FM/SSB voice transmitter (2320 to 2450 MHz). Built on eSpDR by h0m3us3r.

Install (Linux, Python 3.10+)

Download the wheel and install-linux.sh below, then:

chmod +x install-linux.sh
./install-linux.sh esp32_sdr_trx-*.whl --audio       # --audio: a sound card as a transmit source
espdr-rx                                              # receiver: rtl_tcp server on 127.0.0.1:1234 for SDR++
espdr-tx --accept-licence -f 2350 -m usb -i soundcard # transmitter: read docs/transmitter.md first

The wheel contains the firmware images and the tools load the right one into the board's RAM by themselves. Step by step, including the virtual environment and the
udev rule: docs/install.md. esp32-sdr-trx-rx.bin and esp32-sdr-trx-tx.bin are the bare images,
SHA256SUMS lists everything.

Tested

One board (a generic ESP32-S3-WROOM-1 dev board with two USB-C ports), one Linux host, a PlutoSDR and a HackRF as test equipment. Receiver: 20 to 120 s runs without lost samples at
250 and 333 ksps, SDR++ over the bridge. Transmitter: FM and SSB voice from a WAV file, a pipe and a sound card (20 to 30 s without an underrun), five frequencies over the band,
the carrier stops 0.54 s after the host disappears, crystal correction with --ppm. Measured with the carrier suppressed: unwanted sideband 61 to 63 dB and third-order
intermodulation 33 dB below the wanted tones. All numbers: docs/research/TX-RESEARCH.md.

Read before you transmit

Transmitting takes an amateur radio licence. The firmware only sends in 2320 to 2450 MHz. The power is not calibrated (an estimate: microwatts at the antenna of a plain dev board), harmonics and
spurious emissions were not measured, and the frequency is only as good as the board's crystal (use --ppm). Windows and macOS are untested. Much of the code and the documentation was written
with Claude (Anthropic) as the coding assistant; every number in the documentation was measured.

What's Changed

• Docs: the transmitter does not use the I/Q playback engine; it exists… by @jochenhammes in #1
• espdr-tx: RTTY mode and --thermal drift correction by @jochenhammes in #2

New Contributors

• @jochenhammes made their first contribution in #1

Full Changelog: v1.0.0-rc2...v1.0.0-rc3

v1.0.0-rc2

esp32-sdr-trx turns one ESP32-S3 dev board into a software-defined transceiver for 13 cm: an rtl_tcp receiver for SDR++ (1.84 to 2.79 GHz, 250 or 333 ksps, no FPGA) and an
experimental FM/SSB voice transmitter (2320 to 2450 MHz). Built on eSpDR by h0m3us3r.

Install (Linux, Python 3.10+)

Download the wheel and install-linux.sh below, then:

chmod +x install-linux.sh
./install-linux.sh esp32_sdr_trx-*.whl --audio       # --audio: a sound card as a transmit source
espdr-rx                                              # receiver: rtl_tcp server on 127.0.0.1:1234 for SDR++
espdr-tx --accept-licence -f 2350 -m usb -i soundcard # transmitter: read docs/transmitter.md first

The wheel contains the firmware images and the tools load the right one into the board's RAM by themselves. Step by step, including the virtual environment and the
udev rule: docs/install.md. esp32-sdr-trx-rx.bin and esp32-sdr-trx-tx.bin are the bare images,
SHA256SUMS lists everything.

Tested

One board (a generic ESP32-S3-WROOM-1 dev board with two USB-C ports), one Linux host, a PlutoSDR and a HackRF as test equipment. Receiver: 20 to 120 s runs without lost samples at
250 and 333 ksps, SDR++ over the bridge. Transmitter: FM and SSB voice from a WAV file, a pipe and a sound card (20 to 30 s without an underrun), five frequencies over the band,
the carrier stops 0.54 s after the host disappears, crystal correction with --ppm. Measured with the carrier suppressed: unwanted sideband 61 to 63 dB and third-order
intermodulation 33 dB below the wanted tones. All numbers: docs/research/TX-RESEARCH.md.

Read before you transmit

Transmitting takes an amateur radio licence. The firmware only sends in 2320 to 2450 MHz. The power is not calibrated (an estimate: microwatts at the antenna of a plain dev board), harmonics and
spurious emissions were not measured, and the frequency is only as good as the board's crystal (use --ppm). Windows and macOS are untested. Much of the code and the documentation was written
with Claude (Anthropic) as the coding assistant; every number in the documentation was measured.

Full Changelog: v1.0.0-rc1...v1.0.0-rc2

v1.0.0-rc1

esp32-sdr-trx turns one ESP32-S3 dev board into a software-defined transceiver for 13 cm: an rtl_tcp receiver for SDR++ (1.84 to 2.79 GHz, 250 or 333 ksps, no FPGA) and an
experimental FM/SSB voice transmitter (2320 to 2450 MHz). Built on eSpDR by h0m3us3r.

Install (Linux, Python 3.10+)

Download the wheel and install-linux.sh below, then:

chmod +x install-linux.sh
./install-linux.sh esp32_sdr_trx-*.whl --audio       # --audio: a sound card as a transmit source
espdr-rx                                              # receiver: rtl_tcp server on 127.0.0.1:1234 for SDR++
espdr-tx --accept-licence -f 2350 -m usb -i soundcard # transmitter: read docs/transmitter.md first

The wheel contains the firmware images and the tools load the right one into the board's RAM by themselves. Step by step, including the virtual environment and the
udev rule: docs/install.md. esp32-sdr-trx-rx.bin and esp32-sdr-trx-tx.bin are the bare images,
SHA256SUMS lists everything.

Tested

One board (a generic ESP32-S3-WROOM-1 dev board with two USB-C ports), one Linux host, a PlutoSDR and a HackRF as test equipment. Receiver: 20 to 120 s runs without lost samples at
250 and 333 ksps, SDR++ over the bridge. Transmitter: FM and SSB voice from a WAV file, a pipe and a sound card (20 to 30 s without an underrun), five frequencies over the band,
the carrier stops 0.54 s after the host disappears, crystal correction with --ppm. Measured with the carrier suppressed: unwanted sideband 61 to 63 dB and third-order
intermodulation 33 dB below the wanted tones. All numbers: docs/research/TX-RESEARCH.md.

Read before you transmit

Transmitting takes an amateur radio licence. The firmware only sends in 2320 to 2450 MHz. The power is not calibrated (an estimate: microwatts at the antenna of a plain dev board), harmonics and
spurious emissions were not measured, and the frequency is only as good as the board's crystal (use --ppm). Windows and macOS are untested. Much of the code and the documentation was written
with Claude (Anthropic) as the coding assistant; every number in the documentation was measured.

Full Changelog: https://github.com/jochenhammes/esp32-sdr-trx/commits/v1.0.0-rc1