ESP32 Relay Controllers
One-channel and four-channel relay boards with local state reporting, restore behaviour, and Home Assistant control.
Cambridge · Waikato · New Zealand
Electronics Tech builds devices that talk to real hardware.
ESP32 firmware, ET-Bus networks, hydroponic grow systems, LoRa farm telemetry, Home Assistant integrations, relay controllers, sensors, LED systems, PCB prototypes, and 3D printed enclosures.
BUS 239.0.0.1:4242
STATUS LIVE
Built for workshops, homes, and custom installs
Hardware-first automation for farms, grow rooms, workshops, and homes.
ElectronicsTech focuses on local device control, repairable electronics, and clear diagnostics. The work is practical: boards, firmware, wiring, cases, dashboards, water systems, hydroponics, and field-tested examples.
ET-Bus
Local ESP32 device messaging for Home Assistant projects.
ET-Bus is a lightweight local protocol for ESP32 devices such as relay boards, RGB lighting, air sensors, and diagnostic nodes. It is designed around simple JSON state, fast local control, and Home Assistant visibility.
- Relay and switch boards
- WS2812 and RGB lighting controllers
- Temperature, humidity, pressure, air-quality, and battery sensors
- Home Assistant custom component and dashboard work
Project Work
Electronics projects from firmware to enclosure.
Sensor Nodes
AHT, BMP/BME, SGP, battery voltage, and environmental sensor nodes with clean entity mapping.
LED Controllers
WS2812 and RGB lighting controllers using FastLED, reliable state updates, and effect selection.
Home Assistant Components
Custom Home Assistant integrations for ET-Bus devices, MikroTik, Proxmox, Cisco SG300, Zigbee2MQTT monitoring, and local network dashboards.
Hydroponics Controllers
Hydroponic gully, bucket, pot, and Deep Water Culture control with EC, CF, pH, temperature, MQTT reporting, pump dosing, and calibration workflows.
LoRa Farm Links
Long-range node telemetry for farm sensors, garden systems, weather, moisture, and water monitoring.
ESP32 Weather Stations
ESP32-S3 touch display builds with BME280 temperature, humidity, and pressure logging, SD card history, WiFi dashboards, and local reporting.
SMS Control and Alerts
Home Assistant SMS workflows for alarms, status checks, remote commands, and simple phone-based control when app access is not available.
Hydroponic grow systems
Real grow-system control for gullies, buckets, DWC, pots, dosing, sensors, and water movement.
ElectronicsTech has working hydroponics controller code for ESP32 and ATmega builds, including hydroponic gully, bucket, Deep Water Culture, and pot-style grow setups, EC/CF measurement, pH calibration, temperature compensation, TFT touch screens, dosing counters, EEPROM settings, pump timing, and MQTT telemetry.
- Hydroponic gully, bucket, Deep Water Culture, pot, and reservoir monitoring
- Grow-bed layout, return flow, reservoir, and service-access planning
- EC, CF, pH, and temperature measurement
- Calibration screens and saved EEPROM settings
- CF and pH dosing pump control with daily counters
- Water circulation, feed timing, and pump safety logic
- ESP-NOW pump nodes for aeroponics and garden watering
Hydro system design
Gully layout, plumbing, sensors, and control planned as one system.
Grow Layout
Gully rows, DWC buckets, pots, reservoir position, drain return, pump access, and room for cleaning or changing parts.
Water Control
Feed timing, circulation, dosing pump placement, leak-risk reduction, and simple manual fallback controls.
Sensor Points
EC/CF, pH, temperature, tank level, flow checks, and environmental readings placed where they give useful data.
ESP32 Controller
Local firmware, display UI, MQTT/Home Assistant reporting, calibration storage, alarms, and remote telemetry links.
LoRa and remote sensors
Long-range farm and water telemetry for places WiFi does not reach.
Existing project code includes LoRa farm master nodes, ESP-NOW bridges, water tank monitoring, solar sensor nodes, and MQTT gateways. The goal is simple: reliable sensor data from remote sheds, tanks, grow areas, and outdoor equipment.
- LoRa farm master receiving remote node packets
- BME280, SGP30, moisture, light, CO2, and VOC telemetry
- Water tank monitoring with ultrasonic sensing and solar power
- MQTT and Home Assistant reporting for dashboards and alarms
Design and fabrication
PCB prototypes, wiring plans, and 3D printed electronics cases.
Projects can include schematic cleanup, prototype PCB planning, sensor mounting, cable management, enclosure design, and printed cases for finished devices.
Firmware
Arduino, ESP32, WiFi, Zigbee experiments, local network protocols.
Hardware
Relay boards, sensors, LED strips, pumps, LoRa nodes, low-voltage control, bench testing.
Enclosures
3D printed cases, mounting plates, labels, service access, cable paths.
Open Work
Public project code and Home Assistant work.
ET-Bus
Local ESP32 device protocol work for relays, sensors, lighting, diagnostics, and Home Assistant availability.
Home Assistant Custom Components
Local integrations for ET-Bus devices, network health, MikroTik, Proxmox, Cisco SG300, and Zigbee2MQTT monitoring.
ESP32-S3 Weather Station
Touchscreen BME280 environment logger with SD card history, LVGL UI, WiFi access point mode, and a web dashboard for live readings.
Contact
Have an electronics project to build or fix?
Send the board type, device goal, sensors/relays involved, and what system it needs to connect to.