Atmel’s recently launched SAMA5D3 Xplained board is a low-cost, fast prototyping and evaluation platform for microprocessor-based design.
The $79 board, which made its debut at Embedded World 2014, is built around Atmel’s SAMA5D3 ARM Cortex-A5 processor-based MPU and packed with a rich set of ready-to-use connectivity and storage peripherals, along with Arduino shield-compatible expansion headers for easy customization. The platform is also a perfect target for headless Android projects, with a Linux distribution and software package facilitating rapid software development.
Earlier this week, CNXSoft of CNX Software unboxed the $79 board and documented the experience with pictures and detailed observations.
So, let’s get started. CNXSoft kicks off the unboxing by describing the items accompanying the board, including a micro USB to USB cable for power and programming, along with a small card titled “Overview and Compliance Information” which details EU compliance information regarding RoHS2 and EMC (the board is compliant with both CE and FCC standards).
“On the top of the board, we’ll find the 2 USB host connectors, and 2 Ethernet connectors (GMAC and EMAC). On the right, the micro USB port, as well as pads to solder an external power supply and a micro SD slot on the left, reset, wake up and user buttons, as well as JTAG, LCD, and debug (serial) connectors at the bottom, and around the MPU and memories, the Arduino UNO R3 compatible headers with the names of the different pins,” he writes.
“On the back we’ll find the SD card slot, and again, the markings for the Arduino compatible connectors.”
As CNXSoft notes, the board arrrives pre-loaded with a Linux distribution (poky) built with the Yocto Project, comprising bootloaders (AT91Bootstrap and U-boot), the Linux kernel and a custom lightweight rootfs. To get started, simply connect the micro USB to USB cable to a PC to boot the system.
“You should see a blue LED lit up and blink. There’s no display, but there are three ways to access the board from Linux or Windows computers: PC USB, USB to serial and SSH,” he writes.
“You can login with the board using the root account without password. The USB and SSH methods are the most convenient since you don’t need to connect extra hardware, but you won’t be able to access the bootloader that way, debugging the Linux kernel, if needed, will be difficult, and each time, the board is rebooted, the connection will be lost. So for development, you should really get a serial to USB debug board.”
Next, CNXSoft takes a quick look at the kernel version and memory usage, noting 136M free on the rootfs and 21MB used out of 246 MB RAM. He then follows the build procedure found on GitHub, initializing the build directory, adding meta-atmel layers conf/bblayer config files, editing conf/local.conf to specify the SAMA5D3 Xplained board, building and finally, installing the demo image. Subsequently, CNXSoft describes the flash procedure, which comprises the following steps:
- Making sure the board is connected to a PC via the micro USB port
- Removing JP5 (NAND CS, upper left of Atmel MPU) jumper to disable NAND Flash memory access
- Pressing BP2 reset button (bottom left) to boot from on-chip Boot ROM
- Closing JP5 to enable NAND Flash memory access
- Changing the name of copy the device tree blob file
- Running the flash script: chmod +x demo_linux_nandflash.sh
“It will take a little while, and once completed you can login to the board and verify you’ve got a brand new kernel and rootfs. You can also check the flashing log in logfile.log in case something went wrong,” he added.