I think you will agree that Internet of things is pretty ambiguous. Any phrase with the word “things” in it is inevitably somewhat ambiguous, right?
One of those is “computation that is no longer limited to devices with screens, its far more pervasive, it assumes an eventual connection to the cloud and it integrates into and enriches the environment and our everyday lives”.
Regardless of different definitions, ultimately, the Things in the Internet of things need to save us work, save us time, improve our communication with family members, bring us information we didn’t have before, bring us valuable insight in the information that we weren’t previously paying any attention to, and pretty much just improve the way that we, as humans, live and work.
In short Internet of things is a really big deal but lucky for us, it’s also a blast.
Before and After the Internet of Things
Before
- Human beings create data
- Growth is linear
- Cost of entry is significant
- Knowledge is hidden in data
After
- “Things” create data
- Growth is exponential
- Cost of entry is trivial
- Data-based knowledge is mined for humans
The Internet…. of Things
- In the internet as we’ve known it, we have a virtual wire connecting millions of laptops, desktops, phones, servers, etc.
- In Internet of things, those devices are still there but so are a lot of other things. We will learn how to connect our own device to the internet with Raspberry Pi, acting as the brain, so it can communicate with a whole bunch of other fun things.
- I speculate that it will at some point become difficult to think of things that should remain unconnected. We are talking about cars, plants, dog collars, kitchen appliances, parking spots or who knows even may be a human heart. All able to participate in an orchestration that, once again, enriches our lives.
- Off course there are security concerns here, but that has never not been the case with any revolution ever. They’ll rise and they’ll bite us, but we’ll come up with clever ways to outwit the malicious types.
- All of these devices contain installation of small hardware components and also involves a bit of software because of the code to target the hardware it specialized. The specialist hardware is becoming standardized and the specialized software is getting abstracted away with the ability to compose our applications using higher-level frameworks.
Device Landscape
We have talked about IoT and now lets take some time to talk about the devices that can be used as the brains of a project.
There are basically just two kind of devices:
- Micro-controllers
- System on a chip (SOC)
Micro-controllers
Micro-controllers are much simpler system architecture and code that you use to program them is pretty simple too. The most poplular of these micro-contoller based IoT devices is very easily the Arduino.
System on a Chip (SOC)
- Are more complex architecture that allow the chip to run a standard operating system like Windows or Linux, that will let you run node. That’s not the only advantage though.
- Another advantage to running a standard operating system that there are apps and libraries that you are someone else has already written that will often work just fine this IoT environment, even if that’s not what they were originally intended for.
Electronic Components
As we have seen above types of devices involved in IoT projects,but simple or complex these devices are combination of various electronic circuits and components. I think a general introduction of those components will help you to better understand the devices landscape.
Electronic components are discrete devices that somehow modify the behavior of an electronic system.
Active and Passive Components
Components can be categorized into two basic categories. One is passive and the other is active.
Passive Components
A passive component does not require energy to operate, except for the available current from the circuit that it is connected to. All the energy they need to perform their function comes from the circuit they are installed in.
Wire & Cable, Switches, Relays, Resistors, Capacitors, RC circuits to name few.
Active Component
An active component is activated by an external source of power. They need external power source or supply to perform their function. For the most part, active components are made of silicon and called semiconductors. There are two types of silicon, one is called P-type and the other is called N-type. Devices are built by layering these two silicon in silicon sandwiches.
Diode, Transistor, SRC (Silicon-controlled rectifier), the TRIAC, integrated circuits (ICs), Application specific circuits to name few.
Components Categories
Various components, based on their characteristics can be classified into various categories e.g. sensors, feedback components, shields etc. We will see few of those in this post to build the foundation and later more information can be searched if needed via various search engines. There is also a link in the reference section for a you-tube video describing electronic components in detail.
These categories are just logical grouping of these components, in reality these are stand-alone components, these have been tested, can be reused and when arranged in a certain manner, can help us to build circuits very quickly and easily. The good thing is that there is a lot of help available on internet about their applications.
Resisters
It is a passive component. Resister resist the flow of electricity. The higher the value of the resister, the more it resists and less electrical current will flow through it (e.g. we will use this to control how much electricity flows through the LED).
The unit of resistance is called the Ohm, which is usually shorted to to Ω the Greek letter Omega. Because Ohm is a low value of resistence we also denote the values of resistors in kilo-ohms kΩ (1,000 Ω) and mega-ohms MΩ (1,000,000 Ω).
The colored stripes on resisters tell yo the value of the resistor.
Unlike LEDs, resistors do not have a positive and negative lead. They can be connected either way around.
You can also use digital multi-meter to check the value of the resister.
LED’s
Your basic LED is an extremely common sight in IoT projects. LEDs are very interesting little devices, they are actually diodes, what we call PN junction diodes. Diodes are like one-way valve for electricity, they let the current flow one-way but not the other.
It’s a cool little trickyou can do with semiconductor junctions, in the case of LED though, photons are emitted when electricity flows through it.
Single light source LED’s have two wires, notice that one is longer than other so you know which way to push electricity through it.
You cannot directly connect and LED to a battery or voltage source because:
- The LED has a positive and negative lead and will not light if placed the wrong way.
- An LED must be used with a resistor to limit or ‘choke’ the amount of current flowing through it; otherwise; it will burn out.
Sensors
Wikipedia definition ” In the broadest definition, a sensor is a device, module, machine, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor. A sensor is always used with other electronics “
Sensors are simply systems of electronic components that are designed to detect or measure information and interactions, convert them to an analog or digital electronic signal and make it available as an input to the IoT device.
Some common sensors are buttons, temperature probe, photo cell, line sensor, flex sensor etc. I will write about those in my upcoming posts.
Feedback Components
We have discussed LEDs, as they are good examples of components which can provide feedback. Speakers are another example to provide audible feedback for humans. Again I will talk about those in next blog.
Basic LED Demo
Here is schematic and picture of Basic LED demo. I will discuss this setup in a step by step manner in upcoming post. It is here just for your reference and give you a promo of whats coming next. I will also describe in later post about individual components needed and later we will also try various variations of this demo as well gradually from basic to advance.
In later posts you will also learn how to apply Ohm’s Law which we learned in previous post on Electric Circuits. If not, feel free to read that post as well to get some basic information on electric circuits on this URL https://hexquote.com/electronic-circuits-basics/.
Here is the actual wiring and setup:
Summary
Internet of Things is very overloaded term and we will try to understand it in its classic sense. This involves understanding device landscapes and various electronic components which we can use to build very useful, powerful and interesting systems. In this post I barely scratched the surface of this topic and try to write about the related concepts and physical devices. We are starting with micro-controller Arduino and we will see how we can use it in our Iot Projects. Once we are comfortable with it, we will be bringing in Raspberry Pi as well and will also combine both with other interesting electronic components. I also wrote about setting up raspberry Pi in a separate post, you can read it on this URL https://hexquote.com/raspberry-pi-introduction-and-setup/
Till next time, Happy Coding.