> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/vedderb/bldc/llms.txt
> Use this file to discover all available pages before exploring further.

# Applications overview

> How VESC applications map input signals to motor control commands.

A VESC **application** is the firmware layer that receives input signals — from an RC receiver, an analog throttle, a serial controller, or a sensor — and translates them into motor control commands. Only one application runs at a time. You select which one to activate in VESC Tool under **App Settings → General → App to use**.

## Available application types

The `app_use` enum in `datatypes.h` defines every application the firmware recognises:

```c theme={null}
typedef enum {
    APP_NONE = 0,
    APP_PPM,
    APP_ADC,
    APP_UART,
    APP_PPM_UART,
    APP_ADC_UART,
    APP_NUNCHUK,
    APP_NRF,
    APP_CUSTOM,
    APP_PAS,
    APP_ADC_PAS
} app_use;
```

| Value          | Description                                      |
| -------------- | ------------------------------------------------ |
| `APP_NONE`     | No application. Motor sits idle.                 |
| `APP_PPM`      | RC-style pulse-width signal (servo/RC receiver). |
| `APP_ADC`      | Analog voltage throttle or brake.                |
| `APP_UART`     | External controller over serial UART.            |
| `APP_PPM_UART` | PPM input with UART active simultaneously.       |
| `APP_ADC_UART` | ADC input with UART active simultaneously.       |
| `APP_NUNCHUK`  | Wii Nunchuk over I2C.                            |
| `APP_NRF`      | Nordic nRF wireless receiver.                    |
| `APP_CUSTOM`   | User-defined custom application.                 |
| `APP_PAS`      | Pedal Assist System for e-bikes.                 |
| `APP_ADC_PAS`  | ADC throttle combined with PAS sensor.           |

<Note>
  The firmware default is `APP_UART` so the UART port remains available for firmware updates. Change this after your hardware is configured.
</Note>

## Selecting an application in VESC Tool

<Steps>
  <Step title="Open App Settings">
    Connect to your VESC in VESC Tool, then navigate to **App Settings** in the left sidebar.
  </Step>

  <Step title="Choose the application">
    Under the **General** tab, find the **App to use** dropdown and select the application that matches your input hardware.
  </Step>

  <Step title="Configure app-specific parameters">
    Each application has its own configuration tab (PPM, ADC, UART, Nunchuk, PAS). Fill in the values for your hardware.
  </Step>

  <Step title="Write configuration">
    Click **Write App Configuration** to save the settings to the VESC.
  </Step>
</Steps>

## Application pages

<CardGroup cols={2}>
  <Card title="PPM" icon="signal" href="/applications/ppm">
    RC receiver pulse-width input for ESC-style throttle control.
  </Card>

  <Card title="ADC" icon="sliders" href="/applications/adc">
    Analog voltage throttle and brake via the ADC inputs.
  </Card>

  <Card title="UART" icon="terminal" href="/applications/uart">
    Serial communication with external controllers using the VESC protocol.
  </Card>

  <Card title="Nunchuk" icon="gamepad" href="/applications/nunchuk">
    Wii Nunchuk joystick and button control over I2C.
  </Card>

  <Card title="PAS" icon="person-biking" href="/applications/pas">
    Pedal assist for e-bikes based on cadence or torque sensing.
  </Card>

  <Card title="Custom" icon="code" href="/applications/custom">
    Write your own application logic directly in firmware C code.
  </Card>
</CardGroup>

## Runtime API

Applications are managed through `app.h`. The key functions are:

```c theme={null}
const app_configuration *app_get_configuration(void);
void app_set_configuration(app_configuration *conf);
void app_disable_output(int time_ms);
bool app_is_output_disabled(void);
```

`app_disable_output` suppresses motor output for the specified number of milliseconds without stopping the application thread — useful during fault recovery or startup sequencing.