ESPHome AUX AC PCBA
Extension IoT board for AUX air conditioner control via ESPHome
The 3104-01 is a compact, production-grade board that brings your AUX air conditioner into Home Assistant - no soldering or firmware work needed. Built around an ESP32-S3-WROOM-1, it integrates a TPS562203 switch-mode power supply so it runs directly from the AC unit's internal bus (4.8 V to 17 V). A reverse-polarity protection diode guards the board down to -30 V. The board ships pre-flashed with the ESPHome AUX AC component and creates a Wi-Fi hotspot on first boot so you can enter your network credentials right away. Once connected, the device appears automatically in Home Assistant and exposes indoor/outdoor/compressor temperatures, operating mode, fan speed, swing, and presets. The PCB is 25 x 46 mm, two layers, black matte soldermask, single-side population - sized to fit inside or alongside the AC indoor unit.
Key features
- Ships pre-flashed — connects to Home Assistant out of the box
- ESP32-S3-WROOM-1: Wi-Fi + BLE, OTA firmware updates supported
- TPS562203 SMPS runs directly from AC internal bus (4.8 V – 17 V)
- Reverse polarity protection down to −30 V
- UART TX/RX protection resistors safeguard the ESP32 RX pin
- Boot selection button for re-flashing without disassembly
- Compact 25 × 46 mm, single-side, black matte PCB
- Exposes temperatures, mode, fan speed, swing and presets in HA
Specifications
| MCU | ESP32-S3-WROOM-1 |
| Supply voltage | 4.8 V – 17 V (from AC internal bus) |
| Reverse polarity protection | Down to −30 V |
| Power stage | TPS562203 SMPS (3.3 V output) |
| PCB dimensions | 25 × 46 mm |
| PCB stack | 2-layer, 1.6 mm, black matte soldermask |
| Population | Single side |
| Connector | 5-pin (TX, RX, NC, GND, +SUP) |
| Firmware | ESPHome AUX AC component (pre-flashed) |
| Connectivity | Wi-Fi 2.4 GHz + BLE (via ESP32-S3) |
| Revision | 3104-01 |
Offer
Secure checkout via Stripe · Card, BLIK, Klarna, P24
Shipping: Poland ~PLN 22 · Europe ~PLN 89 · Worldwide from PLN 178