Convert factory top-load Polytron washing machines into intelligent, software-defined appliances. Powered by an ESP32 microcontroller, 4-channel AC relays, and a 100% native Android mobile companion app communicating over direct Bluetooth LE.
How software control flows from the mobile phone through the ESP32 microcontroller to 220V AC physical actuators.
Inspect how the native app interface handles real wash cycles, telemetry stream parsing, and hardware control.
No scrolling or paging required to reach emergency controls. Every core wash action is available in a 3×2 high-contrast grid with bold custom icons designed to match the physical touch pod.
The Controls screen acts as a transparent window into the physical hardware. Relays are presented strictly as live state indicators—preventing accidental actuation of conflicting coils while observing motor agitation.
Adding direct Bluetooth Low Energy did not compromise existing smart-home integrations. The ESPHome firmware concurrently maintains its native API port 6053 for Home Assistant, HTTP port 80 for the browser dashboard, and BLE GATT for the companion app.
Wiring configuration between the ESP32 controller and the 4-channel active-low relay module.
| Relay Channel | ESP32 GPIO | Actuator / Load | Electrical Function | Safety Interlock Rule |
|---|---|---|---|---|
| IN2 (Relay 1) | GPIO 19 | Motor A (CW) | Main agitator clockwise wash cycle rotation | 200ms Dead-Time Interlock |
| IN3 (Relay 2) | GPIO 21 | Motor B (CCW) | Main agitator counter-clockwise wash cycle rotation | 200ms Dead-Time Interlock |
| IN4 (Relay 3) | GPIO 23 | Drain Solenoid & Clutch | Opens gravity drain valve and locks drum clutch for spin | 10s Drain Coast Pre-Spin |
| IN1 (Relay 4) | GPIO 18 | Water Inlet Valve | Electromagnetic 220V AC solenoid valve for filling tub | Max 60m Emergency Cap |
| Analog Sensor | GPIO 39 | Water Pressure Sensor | Analog ADC1 channel reading water tub pressure (0–3.3V) | 3.3V Max (Divider Required) |
Service UUID 9f6d1c30-5f2e-4d8a-b7c3-00a1b2c3e001 operating with 1 Hz telemetry pushes and MTU reassembly.
// 1. Inbound Command Characteristic (...e002 write):
> WASH 600 // Start wash agitation mode for 600 seconds
> SPIN 300 // Engage drain & drum clutch, then spin 300s
> PROG 0 // Execute saved sequence in Slot 0 (Cepat)
> SET WASHMIN 12 // Optimistically update parameter and persist to NVS
> STOP // Emergency halt — immediately de-energize all coils
// 2. Outbound Telemetry Characteristic (...e003 read / notify @ 1 Hz):
< ST:WASH|WASH 20min|1/1|120|1080|1000|142|W65
// Format: ST:<MODE>|<PROG_NAME>|<STEP>/<STEPS>|<ELAPSED_S>|<REMAIN_S>|<ABDI>|<HEAP_KB>|W<WATER%>
// MODE: WASH (Agitation active)
// PROG_NAME: WASH 20min
// STEP: 1 of 1
// ELAPSED: 120 seconds elapsed
// REMAIN: 1080 seconds remaining
// ABDI: 1000 (Relay A=ON, Relay B=OFF, Drain=OFF, Inlet=OFF)
// HEAP: 142 KB free
// WATER: 65% tub level