# 2. Connect

The supply powers the motor, the serial adapter connects the PC.

## 1. Connect power and the PC

1. Connect the supply to a power connector: **DC+ to positive, DC− to negative**. Check twice.
2. Connect the serial adapter to the UART connector with the UART cable: TX to RX, RX to TX. 3.3 V only.

    ![The UART connector. TX of the driver goes to RX of the adapter and RX to TX.](https://docs.source-robotics.com/STEPFOC-docs/110/assets/STEPFOC_UART.webp){ width="700" }
    ![The UART connector. TX of the driver goes to RX of the adapter and RX to TX.](https://docs.source-robotics.com/STEPFOC-docs/110/assets/STEPFOC_UART_dark.webp){ width="700" }

3. Power on.

The LED blinks for about two seconds while the bootloader waits for a host. Then the firmware starts, and the LED
stays on steadily: the driver is not calibrated yet, which it reports as an error state.

![On, steady](https://docs.source-robotics.com/STEPFOC-docs/110/assets/Error2.webp){ width="180" }

??? info "The serial adapter alone"
    The serial adapter alone powers the driver's logic: it answers over UART without the supply, but reports a
    Vbus error and will not calibrate or move.

More: [Power and the CAN daisy chain](https://docs.source-robotics.com/STEPFOC-docs/110/04-mounting/power-and-can/) ·
[Connectors and pinout](https://docs.source-robotics.com/STEPFOC-docs/110/03-technical-data/connectors/).

## 2. Open Motor GUI or a terminal

=== "Motor GUI"

    1. Open [motorgui.com](https://motorgui.com/) in Chrome or Edge.
    2. Choose the serial connection.
    3. Press **Connect**, and choose the adapter's port.

    ![Motor GUI connection bar with UART transport, baud rate and Connect](https://docs.source-robotics.com/STEPFOC-docs/110/assets/motor-gui/connection.jpg){ width="800" }

    The driver's identity and state appear: hardware and firmware version, serial number, *Not calibrated*, *No
    errors*.

    If nothing connects: the port, the cable's TX/RX, the browser (Web Serial needs a Chromium browser).

    More: [Motor GUI](https://docs.source-robotics.com/STEPFOC-docs/110/05-setup/motor-gui/).

=== "Terminal"

    1. Open a terminal on the adapter's port: 256000 baud, line ending CR+LF.
    2. Type `#Info`.

    The driver prints its hardware and firmware version, its calibration state and the motor parameters. `#Error`
    prints the active errors.

    More: [The serial terminal](https://docs.source-robotics.com/STEPFOC-docs/110/05-setup/terminal/).

!!! success "Check"
    The driver's identity and live state appear before you change settings. A missing connection is covered in
    [Motor GUI](https://docs.source-robotics.com/STEPFOC-docs/110/05-setup/motor-gui/#opening-the-port) or [Troubleshooting](https://docs.source-robotics.com/STEPFOC-docs/110/08-troubleshooting/).