ChApTEr 2 ■ hArdwArE for IoT SoluTIonS
For more information about the Intel Edison and Sparkfun’s Edison blocks, see Sparkfun’s excellent
guide at https://learn.sparkfun.com/tutorials/edison-getting-started-guide.
JUSt hOW LOW-COSt are theSe BOarDS?
You may be wondering about how much these boards cost. The following are the average prices for
each board in the order they were mentioned. I do not include the Sparkfun Edison blocks because, as
you will see, the price will depend on which blocks you buy, but generally the blocks range in price from
about $15 to $35, with some kits available at a discount. I also omit the older raspberry pi Model B, but
used prices are somewhat below the $30 mark for those boards.- pcDuino3B : $60.00
- Intel Galileo Gen 2: $75.00
- Raspberry Pi 2B: $42.00
- Intel Edison with Mini Breakout: $75.00
- Intel Edison with Arduino Host: $100.00
notice the more expensive boards are the Intel options. Given it’s mostly proprietary hardware, that isn’t
too surprising. The real bargain is the raspberry pi, which partly explains its popularity. however, for the
price and features, the pcduino3B is another of my favorite boards.Now that you’ve seen a variety of boards you can use to host your sensors including microcontrollers
and low-cost computer boards, let’s look at another key hardware component—the sensor.
Sensors
With all this talk of sensors and what sensor networks are and how they communicate data, you may be
wondering what exactly sensors are and what makes them sense. This section and its subsections answer
those questions and more. Let’s begin with the definition of a sensor.
A sensor is a device that measures phenomena of the physical world. These phenomena can be things
you see, such as light, smoke, water vapor, and so on. They can also be things you feel, like temperature,
electricity,^14 water, wind, and so on. Humans have senses that act like sensors, allowing us to experience
the world around us. However, there are some things your sensors can’t see or feel, such as radiation,
radio waves, voltage, and amperage. Upon measuring these phenomena, it’s the sensors’ job to convey a
measurement in the form of either a voltage representation or a number.
There are many forms of sensors. They’re typically low-cost devices designed for a single purpose and
with a limited capability for processing. Most simple sensors are discrete components; even those that have
more sophisticated parts can be treated as separate components. Sensors are either analog or digital and are
typically designed to measure only one thing. But an increasing number of sensor modules are designed to
measure a set of related phenomena.
(^14) Shocking, isn’t it?