MRRC FT-710 — Software SCU-LAN10 Replacement

FT-710 Web Control — FFT spectrum plot + waterfall on iPhone

Features

Complete FT-710 Remote Control

From real FT4222 SPI spectrum waterfall to bidirectional Opus audio, CAT control, and mobile-optimized PTT — every feature built specifically for the FT-710.

Real FT4222 SPI Spectrum

850-point FFT spectrum at ~21 fps from the FT-710 DSP chip via FT4222 SPI. 120-line history waterfall with black→blue→green→yellow→red colormap. Dual-mode: S-meter synthetic fallback when FT4222 is unavailable.

FT4222 SPI direct read (libft4222 + libftd2xx)
4096-byte scope blocks with 0xFF01EE01 sync
~21 fps real spectrum, ~30 fps S-meter fallback

FFT Spectrum Line Plot

Real-time spectrum amplitude vs frequency polyline above the waterfall. Cyan (#06b6d4) line with EMA smoothing (α=0.30), 2× amplitude boost for peak visibility, and horizontal + vertical grid lines aligned with frequency scale.

33px polyline with subtle glow + grid reference
EMA-smoothed (30% new data per frame) — stable peaks
Shared Floor/Ceil controls with waterfall

Bidirectional Opus Audio

RX: FT-710 USB Audio → PyAudio capture (44.1kHz Int16) → frame-aligned resample to 48kHz → Opus 64kbps encode → browser AudioWorklet. TX: browser mic (48kHz) → Opus 64kbps CBR → server resample 48→44.1kHz → PyAudio → radio.

RX 48kHz high-fidelity via AudioWorklet
TX 64kbps CBR with 60ms jitter buffer
Graceful PTT release — word endings preserved
Zero-audio watchdog flags wedged radio USB audio in the status bar

Full CAT Control

Direct serial CAT over the Enhanced COM Port at 38400 baud. 40+ commands: frequency, 15 modes, 23 filter widths, VFO A/B, split, preamp, attenuator, NR/NB/AN, compressor, tuner, AF/RF/Mic gains, S-meter, multi-meter.

No Hamlib / wfview / middleware — direct serial
7-task polling (~296 bytes/sec)
Dirty-field change tracking minimises WebSocket traffic

Mobile-First UI

Optimised for iPhone Safari: safe-area adaptation, PWA manifest with Service Worker offline caching, Wake Lock, Fullscreen toggle. Touch-and-hold PTT with dead-man release.

PWA manifest + Service Worker offline cache
Wake Lock API (screen stays on)
Canvas S-meter S1–S9+60dB + multi-meter (PWR/ALC/SWR/Id/Vd)

7-Task Background Polling

100ms→5s smart intervals at 38400 baud, 0.25s timeout ceiling, active PTT yield. Poll tiers: 100ms (freq/mode/S-meter), 500ms (TX meters zeroed on RX), 2s (filters/gains/NR/NB), 5s (voltage/current/compressor).

~296 bytes/sec total serial utilisation
Auto-zero TX meters on RX transition
0.25s timeout per command — never blocks PTT

Multi-Layer PTT Safety

Touch-and-hold TX → instant release on touch-end. Fire-and-forget TX0 with 500ms TX-status poll + browser watchdog. Server-side forced RX when the last client — or the TX-audio owner — disconnects. Browser unload beacon sends TX0 on tab close.

7 independent release layers — no single point of failure
Server force-RX on last-client or TX-owner disconnect
Graceful TX audio drain before RF drop

iOS App

Native iPhone Client

SwiftUI companion app (iOS 17+) — same 4-channel WebSocket protocol as the browser, tuned for one-handed mobile operation.

Full Radio Control

Frequency (direct entry / step / band jump), VFO A/B, mode, filter width, Preamp/ATT, AGC, NB/NR/ANotch, RF power, mic gain, squelch — all from the iPhone.

4 encrypted WebSocket channels (wss)
Token auth, password in Keychain

Waterfall + Meters

850-bin real-time waterfall with FFT curve, colormap matched to the web UI. S-meter plus TX meters (PWR / SWR / ALC / COMP) and memory channel list.

Same binary spectrum frames as the browser
Dark amber theme, portrait + landscape

Opus Voice RX/TX

RX: Opus 48kHz decode and playback through the device speaker. TX: mic capture at 48kHz in 20 ms PCM frames — hold PTT to talk.

libopus device build (arm64)
Settings: reconnect, gain, volume

Early access — build from source

Requires a physical iPhone (simulator unsupported — bundled libopus is arm64-device-only), iOS 17+, Xcode 15 + XcodeGen, and a TLS-enabled server. The 2026-07-20 audit lists known P0 PTT-safety issues — fixes are designed and in progress. Read the audit before transmitting.

FT710Mobile on GitHub

Architecture

One Process, Three USB Channels

4 WebSocket connections, zero external middleware, built entirely on Python async frameworks.

Serial CAT

CP210x UART · 38400 bps

Yaesu ASCII CMD;

Frequency, mode, VFO, filters, gains, PTT, meters

FT4222 SPI Scope

scope_pipe subprocess

ctypes → libft4222 + libftd2xx

4096-byte blocks, 850-point FFT waterfall

USB Audio

C-Media USB Audio Class

PyAudio capture / playback

RX 48kHz Int16 · TX 44.1kHz mono

WebSocket API

4 endpoints · Token auth

JSON control + Binary audio/spectrum

REST: /api/status, /api/auth, /api/mem_channels

Spectrum

FFT Plot + Dual-Mode Waterfall

FT4222 SPI real spectrum from the FT-710 DSP chip — FFT amplitude line chart above 120-line waterfall, with automatic S-meter synthetic fallback.

850-pt

FFT Spectrum
Per frame from FT4222 SPI

~21 fps

Real Spectrum Rate
FT4222 CLK_DIV_16

~30 fps

S-meter Fallback
Synthetic multi-peak

120

Waterfall Lines
History depth

4096 B

SPI Block Size
0xFF01EE01 sync marker

v2

Spectrum Protocol
1701B frame (1B ver + 2×850B)

Audio

Opus 48kHz Audio Pipeline

Tagged dual-codec transport (Opus 64kbps CBR + Int16 PCM fallback). 12× bandwidth reduction vs raw PCM.

48kHz

RX Sample Rate
Int16 → Opus 64kbps CBR

44.1kHz

TX Playback Rate
160:147 resample from 48kHz

220ms

RX Jitter Buffer
90ms recovery threshold

60ms

TX Pre-buffer
400ms hard cap

64kbps

Opus Bitrate
12× smaller than 768kbps PCM

160:147

Resample Ratio
Linear interp, phase-continuous

Audio Stack

PyAudio PortAudio libopus ctypes AudioWorklet WASM Opus Decoder ScriptProcessor Web Audio API getUserMedia

Download

Windows Desktop Installer

Windows 11/12 x64 — embedded Python 3.12 runtime, no manual Python install. Start Menu launcher with per-user config in %LOCALAPPDATA%.

1 · Install Drivers

Silicon Labs CP210x VCP driver for the FT-710 Enhanced COM Port. FTDI D2XX only if you want FT4222 true spectrum.

Device Manager → Ports (COM & LPT) → Enhanced COM Port

2 · Run the Installer

MRRC-FT710-Setup.exe — v1.6.0, 28.3 MB, x64. Start Menu + optional desktop shortcut.

MD5 2be2a654242f284f73104aea2e010c41

3 · Edit Configuration

Start Menu → Edit Configuration — set the Enhanced COM Port and a strong web password.

%LOCALAPPDATA%\MRRC-FT710\ft710.env

4 · Launch

Start Menu → MRRC FT-710 — the launcher starts the server and opens the browser automatically.

http://127.0.0.1:8888 → login → full control

Download for Windows GitHub Releases

Without the FTDI DLLs the app falls back to the S-meter synthetic spectrum — CAT control and audio are unaffected. macOS / Linux / Raspberry Pi: run from source (steps below).

Quick Start

Up and Running in 5 Minutes

Clone, install dependencies, start the server, open your browser — just four steps.

Clone the Repository

Get the latest code from GitHub

git clone https://github.com/cheenle/mrrc_ft710.git

Install Dependencies

Python 3.12+ with FastAPI, Uvicorn, PySerial, PyAudio, NumPy

cd mrrc_ft710 && pip install -r requirements.txt

Start the Server

Set the serial port and launch — auto-detects FT-710 USB devices

FT710_SERIAL_PORT=/dev/cu.usbserial-XXXX python server.py

Open Your Browser

Any device on your network — phone, tablet, desktop. Default password: ft710

https://server-ip:8888 → login → full control

View on GitHub

Requirements

What You Need

Yaesu FT-710 USB Cable (A→B or C→B) Python 3.12+ macOS / Linux / RPi Modern Browser FTDI libs (for scope)

For real FT4222 SPI spectrum data, install libft4222 + libftd2xx from the wfview app bundle or FTDI website. CAT control and audio work without any FTDI libraries.

One USB Cable Any Device