libcamera_lvds_sam9x75_eb.X

Defining the Architecture

This application demonstrates the use of MIPI CSI DPHY, CSI2DC, ISC and USB peripherals. The camera module used in this application is Sony IMX219 image sensor and this application capture raw video frames of VGA resolution from Sony IMX219 camera module using MIPI CSI2 interface and captured frame is saved to a bmp file and copied it USB drive using SAMA7G54-EK target board.

The camera module can be purchased from this link.

Demonstration Features

• Reference application for the SAMA7G54-EK Board
• Image Sensor Controller (ISC) driver
• MIPI CSI2 DPHY, and CSI2DC drivers
• Time system service, RTT peripheral library and driver
• USB host implementation
• Filesystem implementation
• Analog push button handling
• I2C controller driver

Creating the Project Graph

The Project Graph diagram shows the Harmony components that are included in this application. Lines between components are drawn to satisfy components that depend on a capability that another component provides.

The I2C driver in this project is used for communication with the IMX219 image sensor.

The pins are configured as follows through the MCC Pin Configuration tool:

Clock Configuration

The peripheral clocks need to be turned on for “CSI”, “CSI2DC”, “FLEXCOM8”, “FLEXCOM3” “ISC”, UHPHS, “PIO” and “TC0”.

The Generic clocks need to be turned on for “CSI” with IMGPLL is set to GCLKCSS and GCLKDIV value set to 9.

Interrupts Configuration

The interrupts should be enabled in the “Interrupt for “CSI”, “CSI2DC”, “FLEXCOM3”, “FLEXCOM8” “ISC”, “UHPHS”, “PIOA” and “TC0”.

Note: The IMX219 image sensor is an off-the-shelf module and is not officially supported by MPLAB Harmony 3. While a driver for this module is included as part of this demo, it is not guaranteed to be complete. Nor are the IMX219 configuration values guaranteed to be optimal. The primary purpose of this application is to demonstrate the functionality of the CSI2DC and Image Sensor Controller modules.

Project Configurations

MPU32”s do not have an internal flash memory to boot from. Hence the boot process for these mpu’s is different than for flash based MCUs. The boot process is described in detail in the device datasheets, but the general flow is as follows:

1. On power-up the device executes the first stage bootloader from internal ROM. This looks for an second stage bootloader on external non-volatile memory such as eMMC, SD, NAND flash, NOR-SPI and QSPI as second stage boot devices. For SD and eMMC, ROM bootloader expects a file named “boot.bin” to reside in the root directory of a FAT file system.
2. The second stage bootloader is copied to on-chip SRAM and executed. The second stage boot loader initialize the external DRAM and its controller, then load other program from external non-volatile memory into DRAM and execute it. The second stage bootloader must be configured for the board in use and for the external NVM containing the application. A comprehensive description of the boot process for the Microchip MPU’s can be found in this application note: https://ww1.microchip.com/downloads/en/AppNotes/AN2791-Booting-from-External-Non-Volatile-Memory-on-SAMA5D2-MPU-Application-Note-DS00002791A.pdf
3. The vision application is linked to run/debug on the external DRAM. During a debug process, MPLAB X will first run (load) the at91bootstrap program and this file can be found in the .X folder whose function is to initialize the chip, its clocks, debug port to view log messages and initialize the external DRAM.

Below are Project configuration steps to Debug or Run Vision application. On the MPLAB X IDE, right click on the project and click “Properties”.

1. In “Connected Hardware Tool”, select JLink or J-Tag, and in “Compiler Toolchain”, select XC32 and click apply.
2. Under Categories, click on “Bootstrap”, ensure that “Use bootstrap” is checked and the path to the bootstrap.elf file is set.
3. The harmony.bin should be generated as a post-build command. Under Categories, click on “Building”, ensure that “Execute this line after build” is checked and set “${MP_CC_DIR}/xc32-objcopy -O binary ${DISTDIR}\/${PROJECTNAME}.${IMAGE_TYPE}.elf ${DISTDIR}\/harmony.bin”

Building the Application

The parent directory for this application is in vision/apps/ibcamera_usb. To build this application, use MPLAB X IDE to open the vision/apps/libcamera_usb/firmware/libcamera_usb_sama7g54_ek.X project and press F11.

If the build is successfull, then a harmony.bin file is generate in vision/apps/libcamera_usb/firmware/libcamera_usb_sama7g54_ek.X/dist/imx219_mipi_csi_isc_usb_msd/production folder.

The following table lists configuration properties:

Prebuilt binaries

Latest release prebuilt binaries are available for a SAMA7G54-EK board is here

Configuring the Hardware

Configure the hardware as follows:

• Connect the ribbon cable from the raspberry pi camera module to the MIPI CSI connector on the SAMA7G5EK board.

• Take an SD Card formatted with FAT32 file system, and copy the boot.bin binary file from this location. Also copy the harmony.bin file you generated from the “Building the Application” section.

• Insert the SD card to J4 of the SAMA7G5EK board and power up the board by connecting a powered USB cable to J7 or +5V wall adapter power cable to J1 on the SAMA7G5EK board.

• You can optionally connect an FTDI UART to USB adapter cable to J20.

• Connect USB flash drive formatted with FAT file system.

• Power On the board by Connecting mirco USB Cable to J7 or connecting 5V power supply to J1.

Running the Demonstration

Press the SW3 nSTART button to power-on the board. The green LED will turn On and Off indicating the harmony application is running. Inserting USB stick, USB is attached and a file system is mounted. Once file system is mounted, blue LED turns ON & OFF when an image is captured and Green LED is turns ON When a BMP file is copied to the USB stick and Application is waiting for SW1 “USER BUTTON” event. Pressing SW1 “USER BUTTON” to capture next image. The blue LED turns ON & OFF when an image is captured and Green LED is turns ON When a BMP file is copied to the USB stick and Application is waiting for SW1 “USER BUTTON” event to capture next frame.

Note: It will take around 5seconds for the image to be written to the USB stick.

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