The AtomVM Nif can be used to drive cameras that can be attached to some ESP32 SoCs.

Note. At present, this driver only includes support for the AI Thinker ESP32-cam. Future versions of this driver may include additional SoCs.

This driver is included as an add-on to the AtomVM base image. In order to use this driver, you must be able to build the AtomVM virtual machine, which in turn requires installation of the Espressif IDF SDK and tool chain.

Note. For build instructions of the AtomVM Virtual machine on the ESP32 platform, see here.

Clone this repository in the src/platforms/esp32/components directory of the AtomVM source tree.

shell$ cd src/platforms/esp32/components
shell$ git clone https://github.com/fadushin/atomvm_esp32cam.git

Clone the Espressif esp32-camera component in the src/platforms/esp32/components directory of the AtomVM source tree.

shell$ cd src/platforms/esp32/components
shell$ git clone https://github.com/espressif/esp32-camera.git

Create a component_nifs.txt file, if it does not already exist, in src/platforms/esp32/main. The contents of this file should contain a single line for the ESP32 cam driver:

atomvm_esp32cam

Build and flash AtomVM (typically from src/platforms/esp32)

shell$ cd src/platforms/esp32
shell$ make flash

Once the AtomVM image is flashed to the ESP32 device, it includes NIFs for interfacing with the ESP32 camera on the device.

Note. The atomvm_esp32cam Nif is currently only supported on the the AI Thinker ESP32-cam.

The AtomVM ESP32 camera driver installs additional nifs into the AtomVM virtual machine, which can be used to interface with the camera installed on the ESP32 device. These Nifs provide a simple API for initialization of the ESP32 camera, and for capturing JPEG images.

In order to capture images, you must first initialize the camera. To initialize the camera with all of the defaults, use the esp32cam:init/0 function:

ok = esp32cam:init().

You may specify a configuration properties list with any of the following properties:

-type esp32cam_config_item() ::
    {frame_size, qvga|cif|vga|svga|xga|sxga|uxga}
    | {jpeg_quality, 0..63}.
-type esp32cam_config() :: [esp32cam_config_item()].

The default frame size is xga and the default jpeg quality is 12 (lower is better quality, but larger size.)

To capture a JPEG image, use the captture/0 or capture/1 function. The capture/1 function takes a properties list. Currently, you may specify whether the flash should be on or off (off, by default).

-type capture_param() :: {flash, on|off}.
-type capture_params() :: [capture_param()].

This repository contains a sample program in the examples/esp32cam_example directory for initializing the ESP32 camera and taking a single capture.

This smaple program uses rebar3 to build and flash the application to your ESP32 device. For example,

shell$ cd src/platforms/esp32/components/atomvm_esp32cam/examples/esp32cam_example
shell$ rebar3 flash