Power & USB-C Interface

USB-C Interface

The Snake V1 utilizes a GCT USB4135-GF-A mid-mount USB-C receptacle. This interface serves as the primary gateway for power delivery, firmware updates, and data communication.

Connectivity and Data

While the physical connector is USB-C, the interface operates at USB 2.0 (High Speed) specifications. It provides a standard interface for:

• DFU (Device Firmware Update): Flash the STM32WB35 microcontroller without requiring an external debugger.
• Virtual COM Port (VCP): Serial communication for debugging and interacting with the device’s CLI.
• Peripheral Interfacing: Accessing the onboard microSD card or configuring the CC1101 and BLE modules via PC software.

Hardware Specifications

| Feature | Detail | | :--- | :--- | | Connector Type | USB Type-C (16-pin, Mid-mount) | | Protocol | USB 2.0 | | Data Rate | Up to 480 Mbps | | Durability | Rated for 10,000 mating cycles |

Power Management

The Snake V1 is designed for portable operation, featuring integrated regulation to balance high-performance wireless transmission with battery efficiency.

Power Regulation

The system converts the 5V USB input or Battery DC into a stable 3.3V rail required by the STM32WB35 and the CC1101 transceiver.

• Input Protection: The USB-C interface includes CC (Configuration Channel) pull-down resistors (5.1kΩ) to ensure compatibility with standard USB-C to USB-C cables and chargers.
• Voltage Regulation: High-efficiency Low Dropout (LDO) regulators are used to minimize noise, which is critical for the sensitivity of the Sub-GHz and IR receivers.

Portable Use

To utilize the Snake V1 as a handheld tool, the power circuitry supports:

1. USB Power: Automatically powers the device and peripherals when connected to a host or power bank.
2. Battery Operation: The board is designed to interface with a lithium-polymer (LiPo) battery.
3. Efficiency: The dual-core architecture of the STM32WB35 allows the M0+ core to manage wireless stacks in low-power modes while the M4 core handles the user interface, maximizing runtime.

Usage Example: Checking Power Status

When connected via the USB-C interface, you can monitor the device status through the Serial console:

# Connect via serial (baud rate 115200)
$ screen /dev/tty.usbmodem101 115200

# Snake V1 CLI
> info
Device: Snake V1
MCU: STM32WB35
Power Source: USB-C (5V)
VCC: 3.32V
Status: Charging/Ready

Note: Always ensure your USB-C cable is rated for data transfer if you intend to flash the device. "Power-only" cables will only provide charge and will not mount the device for DFU or Serial communication.