SmartEdge Industrial IoT Gateway
User Guide
http://www.element14.com/gateway
Page 24
File read: start.elf
Second stage boot server done
The eMMC should now show up as a drive on the PC
WRITING A NEW IMAGE OR SAVING EXISTING
Once the eMMC is mounted as a drive, individual files can be accessed or the entire drive contents can be copied or
replaced. While it is possible to use Linux "dd" command to read/write a new image, a safer and more user friendly
tool is recommended (example,
). By default, this tool verifies the image was written correctly, which is
very useful to identify possible cable/port issues.
Download image
Standard Avnet SmartEdge IIoT Gateway images are available through the
http://www.element14.com/gateway
landing page. Click on the Software Image link under Resources.
Standard Raspberry Pi images won't work without some additional files in the /boot partition (refer to section 4.4)
Write the image to the Gateway using an image writing tool. Important: if not using balenaEtcher, you must unzip
the image prior to writing.
3.6.
SYSTEM CUSTOMIZATION
The SmartEdge IIoT Gateway system can be extended with additional hardware or software as needed for your
application.
HARDWARE CUSTOMIZATION
The standard Pi HAT expansion connector opens up a wide variety of ready-made hardware solutions. Custom HATs
can be developed specifically for your application. In many cases, drivers are already available and the HAT can be
plug-n-play. Other HATs may require adding a dtoverlay in the /boot/config.txt file. Mechanically, you can use the
included expansion ring, and customize it for the installed HAT(s). The 3D files can be provided to create your own
expansion ring.
There's a USB header internally that can be used. If designing a custom HAT, a small extension of the HAT board outline
can include this USB header to add USB devices on the HAT.
A mPCIe slot is available to add cards that use the USB bus. This is mostly for cellular modems, but other cards are
possible. Custom cards can be designed if only 3.3V power and USB interface are used.
SOFTWARE CUSTOMIZATION
Because the Gateway is based on the popular Raspberry Pi computer, there are several O/S and Linux distributions
available. Due to differences between the SmartEdge Gateway and Raspberry Pi, standard Pi images these cannot run
without modification. In most cases, the changes are small and straightforward. See section 4.4 for details.
The kernel source is available to customize as needed from our github site (see section 4.1).
There are a large number of software packages available that can be installed using the Ubuntu "apt" mechanism.
There is a battery backed RTC on the gateway. For systems that do not have internet connectivity (I.e. closed system)
then this can be set then enabled with a few standard Linux commands to keep the date/time even if the power fails.
Normally this system is on the internet and the correct time information is provided using network time keeping
protocols.
