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Secondary 3 · Technology
Computational thinking and robotics · Robotics

The Internet of Things

A light bulb that obeys your phone, a wristband that counts your steps, a sensor that tells you there is an open spot in a parking lot in Monterrey: no connected object "thinks" for itself. Each one sends data along a chain of elements to a server that is almost always far away, and it receives commands along the same path. What happens when the internet at your house goes down? By the end of the page you will be able to explain it.

The chain of the Internet of Things

Block diagram of the Internet of Things chain: the sensor sends data to connectivity, connectivity to the platform, and the platform to the app. sensor connectivity platform app each link can fail independently

A control app usually offers three functions: viewing the status of the device, giving commands, and programming automatic rules (for example, "at 7 p.m. turn on the patio light").

The router is your home's door to the internet: if it is turned off or loses service, devices that depend on the cloud stop receiving commands from outside, even though they are still powered on.

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Explain what the Internet of Things (IoT) is and name three connected objects you know, stating what data or "sense" each one provides.

Explain what the Internet of Things (IoT) is and name three connected objects you know, stating what data or "sense" each one provides.

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What does any given object, such as a lamp, need to become a connected object? Mention at least three elements and explain the role of each.

What does any given object, such as a lamp, need to become a connected object? Mention at least three elements and explain the role of each.

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The figure shows how various household appliances are controlled from a smartphone, with one element in the chain marked with ?. Identify this element and explain the…

The figure shows how various household appliances are controlled from a smartphone, with one element in the chain marked with ?. Identify this element and explain the path followed by the command "turn on the light" from when you tap the screen until the light bulb turns on.

smartphone internet ? light thermostat blind
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Name three connected objects in your home or neighbourhood and explain what "job" each one performs: measuring something, providing alerts, or automating something.

Name three connected objects in your home or neighbourhood and explain what "job" each one performs: measuring something, providing alerts, or automating something.

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Explain what an IoT device control app is and what three functions it typically offers (viewing status, issuing commands, programming automated rules).

Explain what an IoT device control app is and what three functions it typically offers (viewing status, issuing commands, programming automated rules).

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A smart plug allows you to turn off a radiator from outside the home. Describe the complete chain the command follows (app, networks, plug) and reason what happens if…

A smart plug allows you to turn off a radiator from outside the home. Describe the complete chain the command follows (app, networks, plug) and reason what happens if the home Wi-Fi stops working.

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A city installs sensors in parking spaces to indicate which ones are free. Describe the complete chain (sensor, communication network, platform, application) and two…

A city installs sensors in parking spaces to indicate which ones are free. Describe the complete chain (sensor, communication network, platform, application) and two measurable benefits of the system.

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Short-range protocols and data encoding

Move the bits and watch how a number becomes a sequence of ones and zeros:

Another case: a TV remote control uses infrared: it needs a line of sight, has a range of a few meters, and does not use the internet, so it leaves no data on any server. Controlling a device over the internet works from anywhere, but it depends on the network and on the company.

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Explain the role played by a Wi-Fi router in a connected home and what happens to smart appliances in the house when the router is turned off or loses internet…

Explain the role played by a Wi-Fi router in a connected home and what happens to smart appliances in the house when the router is turned off or loses internet connection.

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Differentiate between Bluetooth and Wi-Fi as ways to connect a device: range, power consumption, and a typical device example for each.

Differentiate between Bluetooth and Wi-Fi as ways to connect a device: range, power consumption, and a typical device example for each.

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Compare an infrared remote control with controlling a device over the internet: range, network requirement and privacy. Give an example where each option is clearly…

Compare an infrared remote control with controlling a device over the internet: range, network requirement and privacy. Give an example where each option is clearly preferable.

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Local processing versus the cloud

Cloud processing: a device sends its data to the manufacturer's remote servers (the cloud), which communicate with the user's app. device data cloud manufacturer's servers commands and status app

When we talk about "the cloud," it is not something floating in the air: it is a company's computers, in data centers, that store your data. If the company shuts down the service, many devices become "dumb": the hardware works, but there is no one to send the command to.

Local Cloud
Response Very fast With delay
Without internet Keeps working Stops working
Privacy Data stays at home Data goes out to third-party servers
Dependence on the manufacturer Low High
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Explain what "the cloud" means in the context of the Internet of Things: where data is actually stored and what happens to devices if the manufacturer closes the service…

Explain what "the cloud" means in the context of the Internet of Things: where data is actually stored and what happens to devices if the manufacturer closes the service (real-world cases of devices becoming useless or "dumb").

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Compare a device operating locally (all logic contained within the home) with one depending on "the cloud": response latency, privacy, and manufacturer reliance, giving…

Compare a device operating locally (all logic contained within the home) with one depending on "the cloud": response latency, privacy, and manufacturer reliance, giving an example of each type.

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Design an IoT system that alerts a family on their smartphone if the moisture level of a houseplant drops too low: what sensor you would use, how it would connect, how…

Design an IoT system that alerts a family on their smartphone if the moisture level of a houseplant drops too low: what sensor you would use, how it would connect, how the notification would arrive, and how the system would behave when there is no internet connection.

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Home automation rules and how they fail

A home automation rule has the form "if [condition], then [action]": for example, "if the motion sensor detects someone after 8 p.m., turn on the hallway light." The sensor does not "understand" anything: it only compares a reading with a threshold.

Any rule can fail: the sensor gets dirty, the battery runs out, the Wi-Fi goes down, or the condition is poorly thought out. To judge a rule, ask yourself two questions: what happens if it is triggered for no reason? and what happens if it is not triggered when it should have been?

When two rules contradict each other: comfort versus energy

In a system with several actuators, the rules can clash. Think of a classroom with a CO₂ sensor, motorized windows, and heating. If CO₂ goes above 800 ppm (stale air), the health rule says "open the window." But on a cold morning at 5 °C, opening it lets in cold air: the temperature drops and the heating uses more energy to compensate. And if the sun shines straight on the board, closing the blind improves visibility but removes natural light and free heat.

To resolve it, the rules are ordered by priority and conditions are added: health first (high CO₂ takes priority), but with the window open only as long as necessary (for example 5 minutes) and turning off the heating in the meantime; then visibility; energy savings last. That way the system does not open and close nonstop or fight with itself. That is why rules with several actuators are designed together, not one by one.

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Devise a useful smart home rule and another that is a bad idea, both of the form "if [condition], then [action]". Justify each one considering false positives and what…

Devise a useful smart home rule and another that is a bad idea, both of the form "if [condition], then [action]". Justify each one considering false positives and what happens when the rule fails.

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In a smart classroom equipped with CO₂, temperature, and light sensors, the system controls motorized windows, climate control, and blinds. On a cold winter morning (5.0…

In a smart classroom equipped with CO₂, temperature, and light sensors, the system controls motorized windows, climate control, and blinds. On a cold winter morning (5.0 °C outside), the classroom records 1400 ppm of CO₂ (stale air; recommended threshold: 800 ppm), the indoor temperature is 19.0 °C, and direct sunlight is blinding the digital whiteboard. a) Identify the two operational conflicts that arise when trying to simultaneously optimize student health, energy efficiency, and visibility. b) Design the control algorithm using conditional rules (IF... THEN...) that resolves both dilemmas, justifying which objective must have absolute priority in the event of a contradiction.

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Security and privacy

An attacker enters a home network through a smart bulb with a factory password and from there reaches the router, the computer, and the phone. attacker password factory rest of the home network

A strong password is long (12 characters or more), mixes letters, numbers, and symbols, is not reused across devices, and is not a common word or sequence. Leaving "123456" on an IP camera is handing over the way in: attackers try factory passwords and the most common ones first, and they can see the video from your home.

A long password is not enough: you also need to protect the firmware (if the manufacturer leaves holes unpatched), the cloud (if it is attacked, all the accounts fall), and the local network. That is why networks are separated and two-step verification is turned on.

Microphones and cameras: physical switch or software

Smart speakers and cameras have microphones and lenses that can stay on all the time. Muting them with a button in the app or a software setting depends on the firmware: if someone exploits it or the program has a bug, the microphone can keep picking up sound even though the light says "muted."

A hardware kill switch electrically disconnects the microphone. If the circuit is open, no program, no matter how it is attacked, can turn it on: there is no signal to process. That is why it is more reliable than digital muting.

Example: a speaker with a mechanical button that cuts power to the microphone. If an attacker takes control of the software, they cannot activate it, because the microphone gets no power. With software-only muting, on the other hand, the attacker could reactivate it without you noticing. A sliding cover over a camera lens is also a physical barrier: with the cover closed there is no image to record, but it only protects the camera, not the microphone. When a manufacturer says its software is "impenetrable," be skeptical: no software is.

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Explain what characterises a strong password and why leaving "123456" on an IP camera is a serious security issue.

Explain what characterises a strong password and why leaving "123456" on an IP camera is a serious security issue.

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A fitness tracker records your steps and sleep. Reason what sensors it uses, where this data is stored, and which app displays it. What risk to your privacy do you see…

A fitness tracker records your steps and sleep. Reason what sensors it uses, where this data is stored, and which app displays it. What risk to your privacy do you see in this operation?

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A smart thermostat "learns" a family's schedule. Explain what data it needs to record to achieve this, what energy savings or comfort this learning provides, and what…

A smart thermostat "learns" a family's schedule. Explain what data it needs to record to achieve this, what energy savings or comfort this learning provides, and what privacy risk it involves.

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The owner of a tourist rental property installs a smart lock connected via Wi-Fi to the router and claims: "I'm not worried about security: the lock has a 16-character…

The owner of a tourist rental property installs a smart lock connected via Wi-Fi to the router and claims: "I'm not worried about security: the lock has a 16-character random password, so no one from the street can breach it". a) Refute their statement by identifying and justifying two real attack vectors against the lock that do not rely on guessing that password (for example, vulnerabilities in the manufacturer's firmware/cloud or attacks on the local Wi-Fi network). b) Design an improvement in the network and authentication architecture that increases the security of remote access without relying solely on the device's password.

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A family is hesitating whether to install three home automation devices: a thermostat with a presence sensor, a robot vacuum cleaner with a navigation camera, and smart…

A family is hesitating whether to install three home automation devices: a thermostat with a presence sensor, a robot vacuum cleaner with a navigation camera, and smart speakers in the bedrooms. They want to automate their home but demand that no data regarding private habits, floor plans, or voice recordings be stored on third-party servers. a) Analyze for each of the three devices what type of sensitive data it collects and justify whether it is technically feasible for it to operate 100% via local processing (Edge Computing) without connecting to the manufacturer's cloud. b) Establish a technical decision criterion to reject or accept any future connected device in their home, based on data architecture (local vs. cloud) and privacy policy.

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A manufacturer promotes a new smart speaker with the following claim: "To maximize your privacy, our device does not need a physical kill switch: it features smart…

A manufacturer promotes a new smart speaker with the following claim: "To maximize your privacy, our device does not need a physical kill switch: it features smart software that digitally mutes the microphone, making it impenetrable to any cyberattack." a) From the perspective of hardware design and electronic security, refute the manufacturer's claim by comparing the security of a physical switch (which cuts power to the microphone) versus software or firmware muting. b) Explain technically the difference between the audio analysis performed by the low-power local chip to detect the wake word (hotword) and sending the command to the cloud, justifying why maintaining continuous transmission of all domestic audio would be unfeasible both technically and legally.

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In an unsegmented home network, a smart light bulb and a low-cost IP camera share the same Wi-Fi with the personal computer used for online banking and storing backups.…

In an unsegmented home network, a smart light bulb and a low-cost IP camera share the same Wi-Fi with the personal computer used for online banking and storing backups. The camera uses outdated firmware that no longer receives patches from the manufacturer. a) Describe the concept of lateral movement (pivoting), explaining how an attacker who compromises the camera from the Internet could end up intercepting traffic or infecting the personal computer. b) Design a security scheme for this home network using the features of a modern router (segmentation via guest network/VLAN, traffic filtering rules, and isolation of unsupported devices). Justify how your design contains potential threats without preventing IoT devices from remaining useful.

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Sustainability and the IoT business model

Life cycle of an IoT device: manufacturing, standby consumption 24 hours a day, and obsolescence when the cloud no longer has support. manufacturing 24 h standby consumption no support obsolescence connecting everything has a cost that is not always visible

Designing with the planet and all people in mind is designing better: choosing devices that also work locally, that can be repaired and updated, and connecting only what really needs it.

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A school replaces 60 traditional light bulbs with low-cost "smart" bulbs (5.0 W of LED lighting and 1.5 W of continuous standby power consumption due to the Wi-Fi…

A school replaces 60 traditional light bulbs with low-cost "smart" bulbs (5.0 W of LED lighting and 1.5 W of continuous standby power consumption due to the Wi-Fi connection). Three years later, the manufacturer goes bankrupt, shuts down its cloud servers, and the mobile app stops working, preventing them from being turned on or dimmed remotely. a) Calculate the total energy (in kWh) consumed in standby by the 60 bulbs over those 3 years (1095 days) and compare it with the actual lighting consumption if they are turned on 5 hours a day for 180 school days per year. Interpret the result from the perspective of energy savings. b) Explain the "bricking" phenomenon these bulbs suffered and what technical design alternative (local open protocols versus cloud dependency) would have ensured they continued to work after the manufacturer closed down.

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A manufacturer of smart bathroom scales offers two versions of the same product: Model A costs 15.00 pesos and requires creating a free account in its cloud mobile app…

A manufacturer of smart bathroom scales offers two versions of the same product: Model A costs 15.00 pesos and requires creating a free account in its cloud mobile app to record weight, body fat, and heart rates; Model B costs 55.00 pesos and stores data solely in the internal memory and on the user's local network (without external servers or subscriptions). a) Explain the hidden business model behind Model A: how the manufacturer monetizes the price difference at the expense of the user's biometric data, and what risks of commercial profiling or sharing with third parties (such as insurance companies) this entails. b) Technically justify why Model B is more resistant to planned obsolescence and guarantees the user's long-term digital sovereignty, despite its higher initial cost.

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AI and big data in a connected system

A programmed rule ("if the moisture drops below 30, water") is written by a person. An artificial intelligence model learns from examples to predict or recognize images. Big data is data sets so large, fast, or varied that they require special techniques; it is not a synonym for AI. Here we will only look at the idea.

The flow separates two moments: first the model is trained with many examples (images of bottles and cans, in the drawing) and then it is tested with new examples that it did not use to learn. If it were tested with the same examples used in training, the result would be misleading.

Machine learning flow: images of bottles and cans train a model (network of nodes) and then it is tested with new images, with hits and one error. Train with data Model Test with other data

In the test the model is right almost every time, but not always: two out of three in the drawing. A model is only reliable with examples similar to the ones it has seen, and it can learn biases from its data. That is why, faced with a doubtful prediction, a connected system should ask for human review instead of acting alone, and personal data should be limited.

Summary

Go back to the beginning: when the internet goes down, devices that depend on the cloud stop receiving commands even though they are fine; those that process locally keep working.

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