SolarInverterController

ESP32 WiFi controller for MPP Solar / Voltronic inverters — the full rewrite and successor of InverterOfThings (ESP8266).

Out of the box it supports:

Device	Protocol	Notes
MPI Hybrid 10KW (3-phase)	PI17 (^P003GS…)	incl. feed-to-grid control (GPMP)
PIP / Axpert series	PI30 (QPIGS…)	full settings control
PCM60X MPPT charger	PI30 subset	monitoring + charge settings

New inverters are added as pure data files (command tables) — see firmware/src/drivers/profiles/.

Features

• Live SVG dashboard per device type: animated power flow (PV → inverter → battery/load/grid) over WebSocket, warnings, mode badge
• Full control from web + MQTT: output/charger priority, battery voltages and currents, battery type, flags, feed-to-grid power, … all validated against min/max before hitting the wire, every command ACK/NAK-confirmed
• MQTT: structured topic schema + JSON state, command topics with results, availability (LWT), Home Assistant auto-discovery (sensors, switches, selects, numbers), and a legacy compatibility toggle publishing the exact old InverterOfThings topics (incl. the /code raw passthrough) so existing dashboards keep working
• SDM630 integration: a metering ESP32 can steer feed-in via <base>/<name>/cmd/feed_power (watts). A configurable failsafe reverts feed-in to a safe value if the controller goes silent
• WiFi manager: captive-portal AP (SolarSetup-xxxx) when unconfigured, automatic AP fallback (without losing settings) when the network is down
• OTA: browser upload (firmware + web assets) and ArduinoOTA, dual app partitions
• Settings in NVS with JSON export/import; raw command console; status LEDs (red = inverter link fault, green = MQTT) with configurable pins

Hardware

• ESP32 DevKit (classic WROOM-32, 4MB flash)
• MAX3232 level shifter to the inverter's RS232 port
• Inverter TX/RX ↔ MAX3232 ↔ GPIO16 (RX2) / GPIO17 (TX2) — configurable
• LEDs on GPIO25 (red) / GPIO26 (green) — configurable (the legacy GPIO5 is a strapping pin on ESP32, avoid it)
• USB stays free for flashing/debug — no more "disconnect RX to flash"

Build & flash

cd firmware
pio run -e esp32 -t upload      # firmware
pio run -e esp32 -t uploadfs    # web UI (LittleFS)
pio test -e native              # host-side protocol tests

First boot: join the SolarSetup-xxxx WiFi, the setup page opens (or browse http://192.168.4.1), configure WiFi/type/MQTT, reboot. Afterwards the device is at http://ESP-<name>.local.

MQTT topics (base = solar/<deviceName>)

Published: availability (LWT), state (full JSON), sensor/<key> (per datapoint), mode, warnings, device, cmd/result, event. Subscribed: cmd/<setKey> (value), cmd/raw, cmd/feed_power (watts, MPI fast path), heartbeat, legacy code when compat mode is on.

Example — set output priority to SBU:

mosquitto_pub -t solar/inverter1/cmd/output_priority -m "SBU (Solar-Battery-Utility)"
mosquitto_sub -t solar/inverter1/cmd/result

Bench testing without an inverter

pip install pyserial
python3 firmware/tools/inverter_sim.py /dev/ttyUSB0 --type mpi

with a USB-serial adapter crossed into GPIO16/17.

Hardware verification notes (test on first real run)

• MPI PS power scaling: this firmware uses the legacy /10 scaling that was validated on the original MPI 10KW; jblance/mpp-solar treats the same fields as plain watts. If dashboard powers look 10× off, adjust the scales in ProfileMPI10K.cpp (MPI_PS_F).
• MPI setter format: PI17 setters are framed ^Snnn<CMD> without TX CRC (matches legacy + jblance). Verify one harmless setter (e.g. mute_buzzer) before relying on GPMP feed control.
• PCM60X QPIRI/QPIWS field layouts are best-effort from the manual; the QPIGS layout is the legacy-proven one.

Repository layout

firmware/              PlatformIO project (see src/ module layout)
old_inverterofthings/  legacy ESP8266 version (reference only)
reference/mpp-solar/   jblance protocol reference (git clone, not vendored)