Tutorials - Efference

The SDK ships a set of small, self-contained programs under tutorials/, one topic per directory. Each has its own source, README, and build script, and each builds standalone against the installed SDK. Build the SDK first, then build all tutorials or an individual one:

./build.sh                              # from the repo root: SDK + tools
./build.sh --tutorials                  # every tutorial
tutorials/serial_number/cpp/build.sh    # or one, from its own folder

Each binary is named after its source file and lands in that tutorial’s build/:

tutorials/serial_number/cpp/build/serial_number

Wired (USB)

Topic	What it shows
`serial_number`	The minimal program: open over USB and read `DeviceInformation`.
`health_check`	A `health_check()` sweep, with `--deep` for the stress tier.
`data_stream`	The `grab()` to `retrieve_image()` / `retrieve_imu()` loop.
`grab`	A bare open/grab/retrieve loop for throughput checks and debugging.
`wifi_status`	Reading the M1’s WiFi association from the cached snapshot.
`record_and_download`	Record to the device, then pull the MCAP over USB.
`ota_sideload`	Update firmware from a local `.eff` over USB, with no network.

Wireless (Bluetooth LE control, WiFi data)

Topic	What it shows
`discover_devices`	`get_device_list(scan_ble=true)`: find USB and BLE devices without opening one.
`choosing_a_connection`	The same code path over USB or Bluetooth LE.
`wifi_provisioning`	`wifi_add()` and `wifi_select()` over either transport.
`udp_livestream`	The fully wireless data path: BLE control plus WiFi/UDP video and IMU.
`record_and_upload`	BLE control plus a device-driven upload to an S3 or HTTP URL.
`ota_update`	Firmware update over the device’s own WiFi.

OpenCV

Built only where both OpenCV and FFmpeg are present. Both use ef::toCvMat() from <ef/OpenCV.hpp> for a zero-copy view of a grabbed frame as a cv::Mat.

Topic	What it shows
`opencv_display`	`grab()` to `retrieve_image(VIEW::BGR)` to `cv::imshow()`.
`calibrate_camera`	Live checkerboard capture and a Double Sphere intrinsics fit.

Calibration

Topic	What it shows
`calibrate_imu`	Gyro bias and accelerometer ellipsoid estimation, written to the device.

Both calibration tutorials need the prebuilt calibration library for your architecture and are skipped where it is unavailable. They write to the device, so read Calibration before running them.

Walkthroughs

The pages that follow work through the most common of these inline, with the wired and wireless variants side by side.