GPO Home: our own smart-heating platform, from controller board to app

Project goal

Client: our own product. Sold through gpo-store.com and distributors, and offered to manufacturers as a kit.

We make electric heaters. We wanted users to control them from a phone and to pay less when electricity is cheap. Heaters also had to be configurable on site without internet.

Solution

We built every layer ourselves:

• An ESP32 controller board with over-the-air firmware updates, Wi-Fi and BLE provisioning and direct BLE control.
• Smart Install: configuration of heaters over NFC without internet (STM8L).
• A Kotlin Multiplatform app with native interfaces in SwiftUI and Android, in seven languages.
• A cloud platform with digital twins of devices and roles for us, vendors and users, plus a vendor dashboard.
• A cheap mode driven by Nord Pool electricity prices, BLE sensors and an AI assistant with voice input (OpenAI, Whisper).

Results

• About 900 devices on the platform and 300+ customers.
• Apps in the App Store and on Google Play.
• 3,000+ tasks in our issue tracker.

Why it matters for you: If you make a device, this kit — board, firmware, app and cloud — already exists and is offered to manufacturers.