Smart electronics, made in India ·
edgetechlab.pages.devHA-4CH v1 · Smart switch + energy meter · DIY board
Control four appliances from your phone and see how much power they use
An assembled, tested ESP32-C3 board with four relays, a built-in energy meter and inputs for your own switches. It mounts behind the switchboard or in its 3D-printed Edge Tech Lab enclosure.
● Available
₹2,999 board, assembled and tested
Board + 3D-printed enclosurePrice on WhatsApp
Order on WhatsApp:
Pay by UPI after we confirm your order. Ships across India.
+91 79721 13065Pay by UPI after we confirm your order. Ships across India.
What it does
- 4 relay outputs for lights, a fan or a socket, switched from the ESP RainMaker app on Android and iPhone.
- Built-in BL0942 energy meter: voltage, current, power, units (kWh) and frequency.
- The meter is isolated from the Wi-Fi side by optocouplers and an isolated DC-DC converter.
- 4 inputs for your own low-voltage push or latch switches, so you can still switch loads by hand.
- USB-C port with ESD protection for firmware updates. RESET and BOOT buttons.
- Input fuse and surge protector (MOV) on the mains input.
Specifications
| Controller | ESP32-C3-MINI-1, Wi-Fi 2.4 GHz |
|---|---|
| Outputs | 4 × relay (SRD-05VDC-SL-C, contacts rated 10 A 250 VAC) |
| Recommended load | 5 A total across all channels |
| Energy meter | BL0942, 1 mΩ shunt, V / A / W / kWh / Hz |
| Switch inputs | 4, low-voltage dry contact (SWITCH 1–4 and G) |
| Power | 230 VAC 50 Hz, Hi-Link HLK-PM01 supply |
| App | ESP RainMaker |
| Board size | 100 × 78 mm |
In the box
- HA-4CH v1 board, assembled, flashed and tested before dispatch
- Enclosure (if you choose the enclosure option)
- Printed wiring diagram and app setup steps
Not included
- Wires, MCB, switches and the loads themselves
Wiring diagram
HA-4CH v2 · 4 lights + fan + energy meter
Keep your wall switches, add app control, fan speed and energy monitoring
The next board. It reads your existing 230 V wall switches directly, controls a ceiling fan at four speeds with the capacitors on board, and measures the power of everything it switches.
● Coming soon
Coming soon
Send “v2 update” on WhatsApp
+91 79721 13065 to hear when it launches.What’s new in v2
- 4 light channels on Omron G5Q relays rated 10 A each.
- Ceiling fan with 4 silent speeds: three relays select the on-board fan capacitors, with no humming TRIAC.
- 5 inputs for your existing 230 V wall switches, each isolated with an optocoupler. No rewiring of the switchboard to low voltage.
- Energy meter for all loads, isolated from the Wi-Fi side.
- Board temperature sensor for an over-heat cut-off.
- Header for an optional 433 MHz RF remote receiver.
- Milled isolation slots between the 230 V and low-voltage sections.
Design specifications
| Controller | ESP32-C3-MINI-1, Wi-Fi 2.4 GHz |
|---|---|
| Light outputs | 4 × Omron G5Q, 10 A 250 VAC |
| Fan output | 4 speeds (2.2 µF and 3.3 µF capacitors on board, plus full speed) |
| Switch inputs | 5 × 230 VAC, optocoupler isolated |
| Energy meter | BL0942, isolated |
| Power | 230 VAC, Hi-Link HLK-5M12, 1 A fuse, MOV |
| PCB | 112 × 90 mm, 2 layers, 2 oz copper |
| Load rating | Final rating published after heat testing |
How you will wire it
- Mains L and N from the MCB go to the L · N terminal.
- Each light’s live wire goes to OUT 1–4, the fan’s live wire to FAN. Their neutral wires stay on the house neutral.
- The wire that used to go from each wall switch to its light now goes to SW IN 1–5.
- Remove the old fan regulator. Speed is set from the app.
Wiring diagram
Safety. These boards connect to 230 V mains. Have a trained electrician install them, switch off the MCB before wiring, and use a circuit protected by an MCB of 10 A or less.
Do not use them for heavy loads such as geysers, air conditioners or room heaters.
Every board is assembled and tested before dispatch.