SPF 5000 ES Server

A small Go service that reads a Growatt SPF 5000 ES inverter over Modbus and publishes its status and configuration to MQTT. It also provides Home Assistant MQTT discovery and accepts supported configuration commands through MQTT.

Requirements

• Go 1.26.6 or newer
• A Growatt SPF 5000 ES connected through a serial/USB device
• An MQTT broker
• Linux with systemd, polkit, usbreset, and the dialout group for service installation

Quick start

Copy the example configuration:

cp config.ini.example config.ini

Edit config.ini and set at least:

• MODBUS.PORT to the inverter's serial device, such as /dev/ttyUSB0
• MQTT.HOST to the MQTT broker address
• MQTT.USER and MQTT.PASSWORD if authentication is required

For a broker reached over an untrusted network, set MQTT.TLS_ENABLED = true. The system trust store is used by default. MQTT.TLS_CA_FILE can add a private CA; MQTT.TLS_CERT_FILE and MQTT.TLS_KEY_FILE configure mutual TLS, and MQTT.TLS_SERVER_NAME overrides the certificate name when necessary.

Run the server from the repository directory:

go run .

The server reads config.ini from its current working directory. Stop it with Ctrl+C.

Install as a systemd service

On the target Linux machine:

sudo ./systemd/install-systemd.sh
sudoedit /etc/spf5000es-server/config.ini
sudo systemctl enable --now spf5000es-server.service

Useful commands:

systemctl status spf5000es-server.service
journalctl -u spf5000es-server.service -f

The installer leaves the service stopped so the configuration can be reviewed. Pass --start to enable and start it immediately. To build locally and install on another Linux machine over SSH:

./systemd/install-systemd.sh user@hostname

See systemd/README.md for installation and removal details.

MQTT topics

Topics use the configured MQTT.TOPIC_PREFIX (default: growatt/spf5000es):

• .../availability reports online or offline
• .../status/... contains inverter readings
• .../config/.../state contains configuration values
• .../config/.../set accepts supported configuration changes
• .../time_sync/set requests an inverter clock sync

Home Assistant discovery messages use MQTT.HA_DISCOVERY_PREFIX, which defaults to homeassistant.

Development

Run the test suite:

go test ./...

Build the binary:

go build -o spf5000es-server .

This project is licensed under the terms in LICENSE.