BorePilot is an open-source controller board for a single-phase submersible (borewell) pump. An ESP32-S3 switches two relays, reads voltage, current, power and energy from a PZEM-004T module, watches two float switches and reports everything to Home Assistant over Wi-Fi with ESPHome. One board supports three displays (16x2 I2C LCD, I2C OLED or 128x64 ST7920), has START / STOP / MENU buttons, status LEDs and an optional buzzer. A Hi-Link HLK-5M05 makes the 5 V from the mains and USB-C is used for flashing and logs.

Why I made it

Pumps in my area run from a borewell and a tank. I wanted one board that starts and stops the pump from Home Assistant, shows live voltage, current and energy, and stops the pump when it runs dry, with real buttons and a display at the pump as a backup.

What it does

• Two SPDT relays (Songle SRD-05VDC-SL-C) with NO / COM / NC on 5.08 mm screw terminals: START and STOP for a contactor or a small pump.
• PZEM-004T v3 header: voltage, current, power, energy and frequency. Dry-run and over-current protection are planned in the firmware.
• ESP32-S3-WROOM-1U-N16R8 with an external antenna, Wi-Fi, ESPHome and Home Assistant.
• Display options on one board: 16x2 I2C LCD, I2C OLED or 128x64 ST7920. START / STOP / MENU / RESET / BOOT buttons, red status LED, optional buzzer.
• Two float-switch inputs and a spare GPIO header. Optional wireless tank-level node over ESP-NOW (see my TankPilot project).
• Hi-Link HLK-5M05 5 V / 1 A module, 470 uF bulk capacitor, SGM2212 3.3 V LDO, USB-C with ESD protection for programming.

The board

• 100 x 90 mm, 2 layers, 1.6 mm, four M3 mounting holes, 81 parts.
• Mains and relay contact tracks 1.5 mm, +5 V 0.8 mm, +3.3 V 0.6 mm, relay coil 0.5 mm, USB and signals 0.25 mm, ground pour on both layers.
• Two 8 x 1 mm slots around the coil pins of each relay, mains clearance goal 6.4 mm to the low-voltage side.
• Every connector pin and button is labelled on the silkscreen (NO, COM, NC, L, N, START, STOP, MENU, RESET, BOOT and more).
• DRC: 0 errors. The Gerber, BOM and pick-and-place files are attached to this project.

Safety and status

The board switches 230 V AC. It has no on-board fuse or varistor (protect it upstream) and no protective earth through the PCB. Use low-voltage loads on the bench first, keep the terminals covered and have a qualified person review the mains section before you power it. The schematic is ERC clean and the PCB is DRC clean, but the board has not been built or tested yet and the firmware is not written yet.

Files and links

• GitHub (schematic, BOM, Gerber, pick and place, docs, build guides): https://github.com/ElectroIoT/ESP32-S3-BorePilot
• Gerber, BOM, pick and place file and the schematic PDF are attached to this project.
• Parts cost about 16 USD (LCSC listing prices, without the PCB and the PZEM module).

Next steps

Order a small batch, test with low-voltage loads, write the ESPHome firmware (latched pump state, start-up grace time, hysteresis, dry-run guard) and publish the test results.