wifi/softap/mcu_host

# Wi-Fi softap — Host

Run a Wi-Fi **SoftAP** (access point) with the radio on the **coprocessor** and the application on the **host**. `mcu_host/main/softap_example_main.c` is a byte-for-byte copy of upstream IDF `wifi/getting_started/softAP`. Starting the AP netif auto-spawns a DHCP server (dnsmasq / udhcpd) on `192.168.4.1/24` so client STAs get an address out of the box.

## Supported Platforms and Transports

### Supported Coprocessors

| Coprocessor | ESP32 | ESP32-C Series | ESP32-S Series |
| :----------: | :---: | :------------: | :------------: |
| Support     | Yes   | Yes            | Yes            |

### Supported Host Devices

| Host Device | ESP32-P4 | ESP32-H2 | Other MCUs | Linux |
| :---------: | :------: | :------: | :--------: | :---: |
| Support     | Yes | Yes | [Yes](https://github.com/espressif/esp-hosted/blob/master/docs/getting-started-mcu.md) | [Yes](https://github.com/espressif/esp-hosted/blob/master/docs/getting-started-linux.md) |

### Supported Connection buses

| Connection bus | SDIO | SPI Full-Duplex | SPI Half-Duplex | UART |
| :------------- | :--: | :-------------: | :-------------: | :--: |
| Linux host     | Yes  | Yes             | No              | No   |
| MCU host       | Yes  | Yes             | Yes             | Yes  |

## Scenario

The host starts a SoftAP on the co-processor's radio; clients associate to it and the host is notified per client.

```mermaid
sequenceDiagram
    participant App as Host app
    participant CP as Co-processor (Wi-Fi)
    participant STA as Wi-Fi client
    App->>CP: start SoftAP (RPC)
    STA->>CP: associate to SoftAP
    CP-->>App: AP_STACONNECTED (RPC event)
    Note over App,STA: client obtains an IP
```

Select the transport (must match the co-processor) and set the SoftAP credentials:

```bash
cd examples/wifi/softap/mcu_host
idf.py set-target esp32p4
idf.py menuconfig
```

```text
Component config
└── ESP-Hosted
     └── Configure host
          └── Host transport
               ├── Communication bus (co-processor <== bus ==> host)
               │    ├── ( ) SPI Full Duplex
               │    ├── (X) SDIO                    <── default (match the co-processor)
               │    ├── ( ) SPI Half Duplex
               │    └── ( ) UART
               └── SDIO Configuration               ← slot, bus width, GPIOs (defaults OK)
```

```text
Example Configuration
├── (myssid) WiFi SSID
├── (mypassword) WiFi Password
├── (1) WiFi Channel
├── (4) Maximal STA connections
├── [*] Enable GTK Rekeying
└── (600) GTK rekey interval                  ← when GTK rekeying enabled
```

Host dependency config is **pre-set in `mcu_host/sdkconfig.defaults`** (do not remove):

```text
CONFIG_ESP_HOSTED_HOST_FEAT_RPC=y          # RPC control path to the CP
CONFIG_ESP_HOSTED_HOST_FEAT_RPC_EXT_V2=y   # RPC ext-v2 wire (required)
CONFIG_ESP_HOSTED_HOST_FEAT_SYSTEM=y       # system RPCs
CONFIG_ESP_HOSTED_HOST_FEAT_WIFI=y         # host Wi-Fi feature — routes esp_wifi_* to the CP
```

Then flash and monitor:

```bash
idf.py -p <host_usb_serial_port> flash monitor
```

<!-- generated from ../README.md — edit that file, not this one -->