Prusa HeatBed Tile PCB
Heated bed controller with USB-C Power Delivery input and Hall effect sensor for interactive beverage detection.
Prusa HeatBed Tile PCB
A compact, ESP32-S3 based control PCB designed for Prusa-style heated bed tile coasters. It supports USB-C Power Delivery input and integrates weight detection using a Hall effect sensor for interactive beverage detection.
Key Features
- ESP32-S3-WROOM-1-N8 microcontroller with Wi-Fi and Bluetooth LE
- USB-C Power Delivery input (CH221K) negotiates up to 20 V
- 5 V buck converter (AP3503) powers downstream electronics
- 3.3 V LDO (AP2112K) powers ESP32 logic
- Hall effect sensor (DRV5032FAQDBZR) detects vertical movement of platform due to added weight
- Logic-level MOSFET (HY1904C2) to control power output to the heating tile
- Buttons for RST and BOOT
- Test pads and UART breakout for programming/debugging
How It Works
When a beverage (like a cup of tea) is placed on the coaster, the weight causes the platform to compress slightly. This vertical motion brings a magnet closer to the Hall effect sensor mounted on the bottom of the PCB. When the magnetic polarity aligns properly, the Hall sensor outputs a signal indicating the presence of the cup.
This mechanism allows the PCB to detect when a beverage is placed, enabling smart behaviors such as timed heating or status indication.
Power Architecture
| Voltage | Purpose | IC |
|---|---|---|
| 20 V | Input via USB-C PD | CH221K |
| 5 V | Buck-converted output for accessories | AP3503 |
| 3.3 V | ESP32 core logic | AP2112K |
Connectors
- USB-C port (PD source)
- Prusa Tile Connector (4-pin Molex)
- UART test pads for flashing
- MOSFET output (controlled)