DPS50xx

ESP32 firmware for monitoring and controlling DPS5020 programmable DC power supplies over Modbus RTU, with a React web UI for live readouts, setpoint control and charting.

Built on Strux — WiFi, settings, OTA, a log console, optional off-LAN access through a relay, and optional telemetry to InfluxDB all come from the framework. This repo adds the supply.

Supported boards

The board is selected at build time with -DBOARD=<name>; each one lives in main/hardware/boards/<name>/ and owns its own pins, LED polarity and chip target.

Board	Chip	Modbus TX	Modbus RX	LED
dps50xx_esp32 (default)	ESP32 DevKit	GPIO 17	GPIO 16	GPIO 2, active high
dps50xx_c3	ESP32-C3 SuperMini	GPIO 21	GPIO 20	GPIO 8, active low

Modbus runs at 9600 baud on UART1, to unit address 1. The status LED is lit while the supply is answering polls.

Flashing

Download the factory binary for your chip from the Releases page.

Option A — Browser (no install required): Use the ESP Web Flasher and flash the factory binary at address 0x0000.

Option B — Command line:

esptool.py --chip esp32c3 write_flash 0x0000 DPS50xx-esp32c3-factory.bin

After the initial flash, updates can be done OTA from the web UI's firmware page.

Upgrading from a pre-Strux-port build (before v0.2): flash by cable, not OTA. The partition table changed (ota_1 moved, www resized) and an application OTA does not rewrite the partition table.

Web UI

No login step unless you set one: authentication is off entirely while the web.password setting is empty, which is the default.

• Supply — live voltage/current/power, input voltage, CV/CC mode, protection state, setpoint entry, output and key-lock toggles, and rolling charts.
• Device — firmware version, chip, heap, device time.
• Console — device log lines, streamed live.
• Settings — generated from whatever the firmware registered, including psu.poll (poll interval, ms) and psu.telem (record telemetry).
• Firmware — OTA by partition, and independent updates of the web UI.

Controlling it without the UI

Every command is reachable over a WebSocket at ws://<device>/ws, and help list enumerates them off the device itself:

help list -category psu            # what psu commands exist and what arguments they take
psu get                            # the full state of the supply
psu set -voltage 12.5 -current 1.0 # any subset of the setpoints, in one command
psu set -output true

psu set leaves an omitted field alone and skips the Modbus write for anything that did not change, so there is no reason to split a change across several calls.

Building from source

Requires ESP-IDF v6.0+ and Node.js 22+ with pnpm. idf.py build also builds the frontend when pnpm is on PATH.

idf.py set-target esp32                 # or esp32c3 for the C3 board
idf.py build                            # defaults to BOARD=dps50xx_esp32
idf.py -p COM11 flash monitor

For the C3 board:

idf.py -DBOARD=dps50xx_c3 set-target esp32c3
idf.py -DBOARD=dps50xx_c3 build

Frontend on its own (hot reload against a running device — set DEV_HOST in frontend/src/config.ts):

cd frontend
pnpm dev
pnpm typecheck

Adding a board

Copy a folder under main/hardware/boards/, adjust BoardConfig.h, and build with -DBOARD=<your folder>. Only the selected board folder is on the include path. See CLAUDE.md for the layering the rest of the firmware follows.

Remote access

RelayManager can dial out to a relay server so the device is reachable off-LAN; it is off by default (relay.enabled). The relay server itself is not in this repo — it is one server for many devices and it lives in Strux.

License

This project is unlicensed. Use it however you want.