# Drive a single DotBot

Build and flash one DotBot and a gateway, cable them to your computer, and drive
the DotBot from the web UI. This is the smallest real-hardware setup. For the
no-hardware path, use the [simulator](simulator.md) instead.

Building firmware needs SEGGER Embedded Studio and `nrfjprog` (see the README
prerequisites). To skip building, fetch a pre-built release with `dotbot fw
fetch -f <version>` and flash those artifacts instead.

## 1. Build and flash the DotBot

The DotBot v3 is an nRF5340, which has two cores - the application core (your
app) and the network core (the radio) - so you build and flash two images:

```bash
# build the bare dotbot apps into the cache (needs SEGGER Embedded Studio)
dotbot fw artifacts --app dotbot
dotbot fw artifacts --app nrf5340_net --target nrf5340dk-net
# cable-flash to the DotBot whose J-Link serial starts with 77
dotbot device flash dotbot --probe 77                        # app core
dotbot device flash nrf5340_net -b nrf5340dk-net --probe 77  # network core
```

## 2. Build and flash the gateway

The gateway is a dev board (e.g. an nRF52840-DK) plugged into your computer; it
bridges the DotBot's radio to USB serial.

```bash
dotbot fw artifacts --app dotbot_gateway --target nrf52840dk
# cable-flash to the DK whose J-Link serial starts with 10
dotbot device flash dotbot_gateway -b nrf52840dk --probe 10
```

## 3. Drive it from the web UI

With the gateway plugged in, point the controller at its serial port and open
the web UI:

```bash
dotbot run controller --conn /dev/ttyACM0  # serial gateway; no swarm-id needed
```

Select the DotBot in the browser and steer it with the joystick. See the
[controller + web UI guide](controller.md) for the full UI tour, and
[`fw`](../cli/fw.md) / [`device`](../cli/device.md) for the firmware commands.

## Next

- Operate many DotBots over the air - the [`swarm`](../cli/swarm.md) reference.
- Add real-world positions - [LH2 calibration over a cable](lh2-calibration-cabled.md)
  (or [over the air](lh2-calibration.md) once you've provisioned a swarm).