Equipment setup to develop code for an embedded device

Let's begin by keeping it as simple as possible, by using a USB keyboard and mouse and an HDMI monitor just like our desktop system, compiling the code natively on the device, and running our code on the device. Our first step will be to copy the code onto the device, install the build tools, and compile OpenCV and our source code on the embedded system.

Many embedded devices such as Raspberry Pi have an HDMI port and at least one USB port. Therefore, the easiest way to start using an embedded device is to plug in an HDMI monitor and USB keyboard and mouse for the device, to configure settings and see the output, while doing the code development and testing using your desktop machine. If you have a spare HDMI monitor, plug that into the device, but if you don't have a spare HDMI monitor, you might consider buying a small HDMI screen just for your embedded device.

Also, if you don't have a spare USB keyboard and mouse, you might consider buying a wireless keyboard and mouse that has a single USB wireless dongle, so you only use up a single USB port for both the keyboard and mouse. Many embedded devices use a 5V power supply, but they usually need more power (electrical current) than a desktop or laptop will provide in its USB port. So, you should obtain either a separate 5V USB charger (at least 1.5 amps, ideally 2.5 amps) or a portable USB battery charger that can provide at least 1.5 amps of output current. Your device might only use 0.5 amps most of the time, but there will be occasional times when it needs over 1 amp, so it's important to use a power supply that is rated for at least 1.5 amps or more, otherwise your device will occasionally reboot, or some hardware could behave strangely at important times, or the filesystem could become corrupt and you lose your files! A 1 amp supply might be good enough if you don't use cameras or accessories, but 2.0-2.5 amps is safer.

For example, the following photographs show a convenient setup containing a Raspberry Pi 3, a good quality 8 GB micro-SD card for $10 (http://ebay.to/2ayp6Bo), a 5-inch HDMI resistive touchscreen for $30-$45 (http://bit.ly/2aHQO2G), a wireless USB keyboard and mouse for $30 (http://ebay.to/2aN2oXi), a 5V 2.5 A power supply for $5 (https://amzn.to/2UafanD), a USB webcam such as the very fast PS3 Eye for just $5 (http://ebay.to/2aVWCUS), a Raspberry Pi Camera Module v1 or v2 for $15-$30 (http://bit.ly/2aF9PxD), and an Ethernet cable for $2 (http://ebay.to/2aznnjd), connecting the Raspberry Pi to the same LAN network as your development PC or laptop. Notice that this HDMI screen is designed specifically for the Raspberry Pi, since the screen plugs directly into the Raspberry Pi below it, and has an HDMI male-to-male adapter (shown in the right-hand photo) for the Raspberry Pi so you don't need an HDMI cable, whereas other screens may require an HDMI cable (https://amzn.to/2Rvet6H), or MIPI DSI or SPI cable.

Also note that some screens and touch panels need configuration before they will work, whereas most HDMI screens should work without any configuration:

Notice the black USB webcam (on the far left of the LCD), the Raspberry Pi Camera Module (green and black board sitting on the top-left corner of the LCD), Raspberry Pi board (underneath the LCD), HDMI adapter (connecting the LCD to the Raspberry Pi underneath it), a blue Ethernet cable (plugged into a router), a small USB wireless keyboard and mouse dongle, and a micro-USB power cable (plugged into a 5V 2.5A power supply).