-:ref:`cam-resource-allocation` - covers how to allocate camera controller instances with properly set of configurations. It also covers how to recycle the resources when they are no longer needed.
-:ref:`cam-enable-disable` - covers how to enable and disable a camera controller.
-:ref:`cam-start-stop` - covers how to start and stop a camera controller.
-:ref:`cam-receive`- covers how to receive camera signal from a sensor or something else.
-:ref:`cam-callback`- covers how to hook user specific code to camera controller driver event callback function.
-:ref:`cam-thread-safety` - lists which APIs are guaranteed to be thread safe by the driver.
-:ref:`cam-kconfig-options` - lists the supported Kconfig options that can bring different effects to the driver.
-:ref:`cam-iram-safe` - describes tips on how to make the CSI interrupt and control functions work better along with a disabled cache.
A camera controller driver can be implemented by the CSI peripheral, which requires the configuration that specified by :cpp:type:`esp_cam_ctlr_csi_config_t`.
If the configurations in :cpp:type:`esp_cam_ctlr_csi_config_t` is specified, users can call :cpp:func:`esp_cam_new_csi_ctlr` to allocate and initialize a CSI camera controller handle. This function will return an CSI camera controller handle if it runs correctly. You can take following code as reference.
A camera controller driver can be implemented by the ISP DVP peripheral, which requires the configuration that specified by :cpp:type:`esp_cam_ctlr_isp_dvp_cfg_t`.
If the configurations in :cpp:type:`esp_cam_ctlr_isp_dvp_cfg_t` is specified, users can call :cpp:func:`esp_cam_new_isp_dvp_ctlr` to allocate and initialize a ISP DVP camera controller handle. This function will return an ISP DVP camera controller handle if it runs correctly. You can take following code as reference.
Before calling :cpp:func:`esp_cam_new_isp_dvp_ctlr`, you should also call :cpp:func:`esp_isp_new_processor` to create an ISP handle.
If a previously installed camera controller driver is no longer needed, it's recommended to recycle the resource by calling :cpp:func:`esp_cam_ctlr_del`, so that to release the underlying hardware.
Before starting camera controller operation, you need to enable the camera controller driver first, by calling :cpp:func:`esp_cam_ctlr_enable`. This function:
Before receiving camera signal from camera sensor, you need to start the camera controller driver first, by calling :cpp:func:`esp_cam_ctlr_start`. This function:
After the camera controller driver starts receiving, it can generate a specific event dynamically. If you have some functions that should be called when the event happens, please hook your function to the interrupt service routine by calling :cpp:func:`esp_cam_ctlr_register_event_callbacks`. All supported event callbacks are listed in :cpp:type:`esp_cam_ctlr_evt_cbs_t`:
-:cpp:member:`esp_cam_ctlr_evt_cbs_t::on_get_new_trans` sets a callback function which will be called after the camera controller driver finishes previous transaction, and tries to get a new transaction descriptor. It will also be called when in :cpp:func:`s_ctlr_csi_start`. If this callback does not get a new transaction descriptor, the camera controller driver will use the internal backup buffer if ``bk_buffer_dis`` flag is set.
-:cpp:member:`esp_cam_ctlr_evt_cbs_t::on_trans_finished` sets a callback function when the camera controller driver finishes a transaction. As this function is called within the ISR context, you must ensure that the function does not attempt to block (e.g., by making sure that only FreeRTOS APIs with ``ISR`` suffix are called from within the function).
- Enables the interrupt being serviced even when the cache is disabled
- Places all functions that used by the ISR into IRAM
- Places driver object into DRAM (in case it is mapped to PSRAM by accident)
This allows the interrupt to run while the cache is disabled, but comes at the cost of increased IRAM consumption. So user callbacks need to notice that the code and data inside (the callback) should be IRAM-safe or DRAM-safe, when cache is disabled.
*:example:`peripherals/camera/camera_dsi` demonstrates how to use the ``esp_driver_cam`` component to capture signals from a camera sensor and display it on an ILI9881C LCD screen via a DSI interface.
