Expert Amp Server is a small Go server for local-network monitoring and control of SPE Expert amplifiers. Run it near the amp, open it from a browser, and get a practical amp panel without needing the vendor Windows app on the operating computer.
It is meant for radio-side computers like a Raspberry Pi, an Apache Labs ANAN G2 internal Raspberry Pi Compute Module, or any small Linux box that can talk to the amp's built-in USB Type-B control port.
- Mirrors the SPE LCD display in a browser.
- Provides Front Panel and compact Operator layouts for day-to-day amp monitoring and control.
- Gives you local-network amp controls: operate/standby, power level, antenna, input, tune, display/menu controls, and power-off where supported.
- Adds display-verified manual and automatic fan cooling with timed Fan Boost, plus optional state-gated overtemperature standby protection.
- Includes a disabled-by-default Menu Debug & Reporting wizard for automatic evidence-gated fan compatibility tests and sanitized reports; bank topology remains available to explicit API clients.
- Exposes a documented HTTP/WebSocket API for custom integrations, station dashboards, Node-RED flows, and future Thetis-style gauge work.
- Ships a bootstrappable Node-RED dashboard example.
- Includes Raspberry Pi/systemd install notes and a release build helper.
- An SPE Expert amplifier. Development and fan-control hardware testing use a First Series Expert 1.3K-FA. Users have also reported the server working on Expert 1.5K-FA and 2K-FA amplifiers; one 2K-FA installation uses the confirmed 57600 troubleshooting fallback.
- A Raspberry Pi or other small Linux computer near the amp.
- A USB cable from that computer to the amp's built-in USB Type-B control port. Do not use the separate CAT radio serial ports for Expert Amp Server.
- A trusted station LAN so your browser, Node-RED host, logger, or radio-control computer can reach the server.
One practical setup is an Apache Labs ANAN G2 / G2 Ultra with its internal Raspberry Pi Compute Module connected directly to the amp over USB. If you use Saturn/p2app remotely, see also the related p2app SPE CAT work for feeding band/frequency/TX state to the amp from the radio side.
Expert Amp Server is a trusted-LAN station appliance. The default listen address :8088 intentionally accepts connections from other machines on the local network because the normal setup is a radio-side Pi serving a browser, logger, Node-RED instance, or radio-control PC elsewhere on the same LAN.
Do not expose it directly to the public internet. The HTTP API includes state-changing routes for amp controls, settings, wake, and restart, and it does not currently implement authentication. Use a trusted station LAN, VPN, firewall, or reverse proxy for remote access.
This software controls RF hardware. It is believed to match the documented and observed transport behavior, but you are responsible for deciding whether it is appropriate for your station and amplifier.
git clone https://github.com/FtlC-ian/expert-amp-server.git
cd expert-amp-server
go run ./cmd/server -addr :8088 -poll-interval 125msOpen http://localhost:8088/.
If no serial port is configured, the app starts in setup/fixture mode and the Settings tab lets you enter a persistent config. For real installs, prefer an explicit config path; see the Raspberry Pi install guide.
The advanced serialAssertDTR and serialAssertRTS settings default to true when absent. Set them to false for transports such as PTYs or network serial bridges that do not support modem-control ioctls; explicit false values remain preserved across settings saves and restarts.
Canonical API routes live under /api/v1/....
Useful starting points:
curl http://localhost:8088/healthz
curl http://localhost:8088/api/v1/version
curl http://localhost:8088/api/v1/status
curl http://localhost:8088/api/v1/runtime/snapshot
curl http://localhost:8088/api/v1/display/text | jq
curl -o screen.png http://localhost:8088/api/v1/display/render.pngGET /api/v1/display/text provides the current eight-row LCD as fixed-width decoded text, including highlighted ranges and selected text for screen-reader clients. The bundled display-capture command can passively record unique display states using GET requests only. See Display accessibility and passive capture for the response contract and capture workflow.
The app also serves:
- OpenAPI JSON at
/api/v1/openapi.json - local API docs at
/api/v1/docs - status websocket at
/api/v1/status/ws - display invalidation websocket at
/api/v1/display/ws
Manual Fan Boost, Fan Normal, Fan Auto, and Verify controls use a display-verified transaction instead of a blind button macro. The controller temporarily enters STANDBY when necessary, pauses all menu writes during TX, verifies each expected LCD screen, saves the setting, and restores OPERATE only when it owned that transition. A timed Fan Boost begins its timer only after CONTEST mode is verified.
Production fan control is hardware-confirmed on the First Series Expert 1.3K-FA and CONFIG-first Second Series Expert 1.5K-FA. The API advertises supportedModes per promoted model; both profiles report normal and contest. Unsupported models report no modes and stop before SET; an unexpected screen stops the transaction rather than continuing.
Each navigation receipt retains the newest 32 exact verified semantic LCD waypoints in navigation.waypointTrace, suppresses consecutive duplicates, and reports any one-shot DISPLAY recovery attempt and recognized origin separately. It never includes raw LCD content, and a replacement transaction starts with a fresh trace.
Unattended startup verification has one narrowly reviewed recovery capability for the First Series 1.3K-FA and Second Series 1.5K-FA: after a mismatch or timeout while actively traversing that profile's exact setup-grid waypoint, it may send DISPLAY once and retain ownership until a newer checksum-valid STANDBY/RX home frame arrives. It never runs from a submenu, stale or cross-family screen, TX or unknown RX state, another model, or a manual/API transaction. Recovery does not make verification successful; the failed transaction remains latched until explicitly cleared.
Automatic fan cooling is disabled by default. Optional overtemperature standby is separately armed, requires fresh protocol-native OPERATE and RX status, sends one documented OPERATE toggle per hot episode, and never retries, powers off, or wakes the amplifier.
Important upgrade note: the amplifier status protocol sends temperature numbers without a unit. Before enabling temperature monitoring or fan automation, set amplifierTemperatureUnit to match the amplifier SET menu (C or F). All thresholds and API fields ending in C remain canonical Celsius.
SPE documents a maximum rate of 115200 with automatic adaptation to lower speeds, so that remains the server default. One field-tested 2K-FA installation only communicated reliably at 57600; use that as a troubleshooting fallback, not as a model-wide requirement.
The advanced Menu Debug wizard is disabled by default and intended for supervised compatibility testing. Arming requires the exact acknowledgement, fresh protocol STANDBY/RX, a checksum-valid STANDBY home display, inactive fan control, disarmed overtemperature standby, and an exclusive actuation lease. The built-in wizard requests only the fan capability, so successful fan verification finalizes its report without silently continuing into separate bank discovery; API clients may still request bank topology explicitly. One guarded start runs discovery and the frozen apply plan automatically, but every command still receives one authorization and waits for newer matching display evidence before the next command. The wizard pauses for physical candidate confirmation, restores automatically only after a positive answer, then pauses again for physical restored confirmation. A serial reconnect or an observed change to a different identified model invalidates the entire active session and discards all report evidence, so different hardware cannot continue or relabel it.
The reviewed First Series Expert 1.3K-FA profile may propose reversible fan and two-bank A/B tests. The Expert 1.5K-FA Second Series fan profile follows its captured CONFIG-first topology; both fan profiles have physically verified apply and restoration evidence and are eligible for production fan control. Unknown models and F-KFA NORMAL/QUIET layouts remain topology-only; QUIET is never treated as high cooling. TX is latched immediately. TX, stale evidence, an unexpected screen, timeout, abort, transport failure, or safety preemption stops the session fail-closed; the wizard never retries blindly, restores OPERATE, or performs blind menu recovery.
The reporting wizard has one candidate-only Expert 2K-FA Third Series transaction bound to the exact model, setup topology, and firmware Rel.26_03_24_A. From verified STANDBY/RX it records a reversible hardware NORMAL (high cooling) → QUIET (low cooling) → NORMAL test, never sends DISPLAY, and remains separate from production fan control until the resulting apply/restore report and missing raw fixtures are reviewed. Second Series setup recognition accepts either input number.
For unfamiliar layouts, discovery may enter an exact highlighted fan candidate only when the live legend says [SET]:CONFIRM; [SET]:CHANGE stops before SET because it may write immediately. Once a candidate fan page is captured, the wizard sends no selector, SAVE, or DISPLAY command and retains exclusive actuation ownership until the operator physically returns the amplifier to a newer checksum-valid STANDBY home screen.
menu-report.v2 reports can be previewed and downloaded locally. They include normalized rows and exact raw 8x40 character/attribute grids for hardware receipts. Ordinary failure, abort, and expiry retain an explicitly incomplete diagnostic report; reconnect or model change still invalidates report access. Incomplete reports cannot be uploaded. Completed-report upload requires explicit consent and defaults to the public receive-only collector at https://expert-amp-menu-reports.sociallabs.workers.dev/v1/menu-reports, so testers do not need to configure an internal endpoint. Override it with -menu-report-collector-url or EXPERT_AMP_MENU_REPORT_COLLECTOR_URL for development or self-hosting; pass an empty command-line value to disable uploads. Common IP, URL, email, callsign, and serial-device patterns are redacted, session tokens are omitted, and operators must review the local preview before consenting to upload.
Start here:
- Raspberry Pi install guide
- Architecture
- Display accessibility and passive capture
- Protocol notes
- Node-RED integration guide
- Screenshot/reference index
- Release readiness checklist
- Changelog
TARGETS="linux/arm64" VERSION="$(git describe --tags --always --dirty)" packaging/scripts/build-release.shThe release helper injects build metadata into the server binary and copies the sample config plus systemd unit into dist/.
MIT. See LICENSE.