Tag Archives: AI

AI On the Edge, Raspberry Pi

AI on the Edge LESSON 26: Understanding the HSV Color Space in OpenCV

Hey guys, welcome back to the channel. If you’ve been following along, you know we’ve been pushing our hardware absolutely down into the dirt. We’ve been running large language models right on the edge, pushing our boards hot and heavy until the silicon is screaming and the thermal throttling flags are popping up all over the place.

But today, we are stepping away from the heavy-compute server terminals, and we are getting back to our roots: Real-Time Computer Vision and Embedded Control. In our previous lessons, we learned how to hook up our high-speed camera, capture raw frames, and interact with individual pixels using standard RGB/BGR math. But today, we are going to look under the hood of a completely different way of representing color: The HSV Color Space (Hue, Saturation, Value).

If you try to track objects or isolate specific colors in the traditional RGB world, you are going to pull your hair out. The moment a shadow hits your object or the room lighting changes, your Red, Green, and Blue values completely collapse. By shifting our mathematics into the HSV space, we can lock onto a color’s pure identity regardless of whether it is sitting under a bright laboratory spotlight or a dim shadow.

Not only are we going to capture and process these video streams at a smooth-as-silk 60 frames per second, but we are also going to translate that raw visual math directly into the physical world. We are using our trusty SunFounder Fusion HAT+ to dynamically pulse an external RGB LED, matching its brightness and color hue perfectly to whatever pixel your mouse is clicking on in real-time.

Let’s look at the blueprint to make this happen.

The Complete Python Code

Here is the clean, un-guardrailed Python script for today’s lesson. Paste this directly into your local terminal workspace. No bloated libraries, no unnecessary frameworks—just pure, deliberate engineering.

Under the Hood: How the Code Works

1. The Real-Time Telemetry Smooth Filter

Look closely at how we calculate our frames-per-second metric inside the main processing loop:

If you simply print out the raw math of 1 / deltaT, your numbers on the screen are going to jump all over the place like a wild animal. By applying a 95% historical weight and a 5% instant weight, we create a low-pass software filter that smoothly tracks our true hardware operational speed without erratic layout jitter.

2. The Mouse Vector and BGR Array Sequence

When your mouse triggers an event over the window, OpenCV passes us the standard coordinate pairs (x, y). But remember: inside a NumPy data structure, images are structured as Rows first, then Columns. That means when you slice into your image array to read a pixel’s color values, you must pass the parameters as frame[y, x]. If you pass it as [x, y], your program is going to index out of bounds and crash hard.

Furthermore, always remember that OpenCV handles colors in a BGR (Blue, Green, Red) sequence, not RGB. When we extract those elements, they unpack straight into valB, valG, valR.

3. Masking and Bitwise Isolation

To lock onto our target color, we use cv2.inRange() to look at our HSV frame and check it against our lower constraint (LC) and upper constraint (UC). This generates a Mask—a pure black-and-white image where pixels within the target color space are completely white (255), and everything else is completely black (0).

By taking that mask and running a fast bitwise operation

We force the computer to evaluate every single pixel. If the mask is zero, the output is blacked out. If the mask is active, the original, rich color information passes through perfectly, isolating our target object from the background noise instantly.

Get your circuits wired up, get this script running on your machine, and let me know in the comments section below what kind of performance numbers you are pulling on your local workbench. I’ll catch you guys in the next lesson!

Remember we are still setting the LED color to the color that cursor is pointing at. This is the circuit for connecting the RGB LED.

Fusion Hat Circuit Diagram
This is the circuit we will use moving forward in the class
NVIDIA

Edge AI on the NVIDIA Jetson Orin Nano: You are Running With the Big Dogs Now!

Welcome back. If you are watching this, you’re ready to stop playing with toys and start building real-world AI. Today, we are looking at the NVIDIA Jetson Orin Nano. Let’s get one thing straight: this is not a Raspberry Pi.

Under the hood, you are working with an Ampere-architecture GPU featuring 1,024 CUDA cores and 32 Tensor cores. You have a 6-core ARM Cortex-A78AE v8.2 64-bit CPU. Depending on how you configure your power mode, you are looking at anywhere from 20 to 40 TOPS of AI performance. This is raw, unadulterated horsepower that can process multi-stream video pipelines in real-time. In the 15W mode, you are managing a delicate balance of thermals and throughput; in the 25W mode, you are pushing the limits of the silicon itself. But this power comes with a price. You have been playing in an amusement park, but now, you’re going skydiving. The guardrails are gone.

The Skydiving Mindset: In the Pi or Arduino world, everything is ‘turn-key.’ You follow the recipe, you get the cake. It’s safe. It’s predictable. But when you are dealing with 40 TOPS of compute, the environment is fundamentally different. There are no guardrails here. If you don’t do the work, if you don’t check your own gear, you hit the ground.

There is a fundamental shift in responsibility when you move from consumer hobbyist boards to professional embedded silicon. You aren’t just a user anymore; you are an architect. If you’re looking for a guaranteed result because you clicked a link, go back to the Pi. If you’re looking to master high-performance silicon, welcome to the deep end. We are ‘Running with the Big Dogs’ now.

The Infrastructure Tax: Let’s start with the cost of entry. If you are trying to develop on an Orin using a Virtual Machine or a dual-boot setup on your Windows gaming laptop, stop. Just stop. You are setting yourself up for a failure that has nothing to do with the board and everything to do with your infrastructure.

I’ll give you a horror story. I tried to dual-boot my main workstation to make it ‘easier’ to access the Ubuntu environment needed for the SDK Manager. I triggered a BitLocker conflict. It didn’t just break the bootloader; it effectively bricked my NVMe drive so thoroughly that I had to dump the drive, buy a replacement, and reload my entire backup image from scratch.

That is the ‘Big Dog’ tax. Professionals don’t risk their primary workstation for a development tool. You build a dedicated, stand-alone Ubuntu machine. That is the cost of entry. If you can’t commit to a clean Linux environment, you aren’t ready for this hardware. The SDK Manager requires low-level USB access and partition control that hypervisors simply cannot handle reliably. You want to play with the big silicon? You bring the right infrastructure.

The Illusion of Instructions: You’ve probably heard people complain that my instructions didn’t work. Or they get angry at NVIDIA because the latest JetPack caused a kernel panic. I want to tell you the truth: You aren’t following instructions; you’re following suggestions.

Look at JetPack 7.2. Thousands of people followed the official documentation to the letter, and for half of them, it failed. The ‘Super Mode’ didn’t show up. And in the frantic attempt to force it to appear, many of them bricked their boards. When you brick an Orin—and you will—you don’t get a ‘reset’ button. You get a terminal, a flashing USB cable, and the SDK Manager.

When you’re flying a jet, you don’t blame the manual when the engine flame-outs. You check the instrumentation. The Jetson is your instrumentation. If it says ‘Over-Current,’ you don’t get mad at the manufacturer—you analyze your power budget. You are pushing hardware to its thermal and electrical limits. You are choosing your destiny with every power-mode configuration you change. This isn’t a software update; it’s a battlefield.

The Oracle of Delphi: Now, let’s talk about the NVIDIA forums. Think of those forums as the Oracle of Delphi. You do not walk into that house and demand service. If you post, ‘I followed the instructions and it broke, what a goat rodeo, you guys released a broken OS,’ you are done. You will be ignored, and you will lose all professional credibility.

Here is the 12-Hour Rule: Before you post, you spend 12 hours of deep-dive, log-file-reading, self-inflicted pain on your own. You read the dmesg output. You check your logs in /var/log/syslog. You look at jtop and you watch the power rails. If you can’t describe exactly what is happening, you aren’t ready for help.

When you do post, you provide a reproduction script. You provide data. You treat those engineers with the respect they deserve. And when they respond? You shut up and listen. They are the pilot; you are the co-pilot. You do not touch the controls. You follow their lead, you execute their tests, and you report the results. Any frustration you express makes you look like a hobbyist who doesn’t understand the complexity of what they are touching. You are a guest in their house. Earn your stay.

Log-Driven Development: If your terminal isn’t covered in log outputs, you aren’t debugging—you’re guessing. Guessing is for hobbyists. Engineers measure. In the Pi world, you just write code and it works. On the Jetson, you have to think like an architect. Is your code saturating the memory bandwidth? Is your model actually hitting the Tensor cores? If you treat the Orin like a general-purpose PC, you are wasting the most powerful tool on your desk. You have to learn the power envelope. You have to learn the thermal limitations. You are driving a Ferrari in first gear if you don’t understand what’s happening under the hood.”

The Verdict: So, here is my promise to you. You will brick it. You will want to throw it against the wall. But the moment you decide to solve the problem instead of blaming the manufacturer, that is the exact moment you stop being a hobbyist and start being an engineer. You want to run with the Big Dogs? Then stop whining about the guardrails and start learning how to read the logs. See you in the next lesson.

So the question for you now is, are you really ready to Run with the Big Dogs? Are you ready to jump into the deep end of the pool, or do you want to return to the wading pond?

AI On the Edge, Tutorial

AI on the Edge LESSON 23: Creating Regions of Interest (ROI) in OpenCV with Slicing

Welcome back, everyone! In this lesson, we are stepping into a foundational aspect of computer vision: manipulation of specific regions within a video frame.

Up to this point, we have been grabbing the full frame from our camera and performing operations on the entire image. But in real-world edge AI and robotics applications, processing every single pixel of a high-resolution frame is an absolute waste of compute power. If you want to detect a license plate, track a face, or monitor a specific sensor layout on a machine, you don’t need to look at the sky or the floor. You need to isolate a Region of Interest (ROI).

In this lesson, you will learn how to use Python’s powerful matrix slicing capabilities to chop up a frame, isolate specific quadrants, manipulate pixels inside an ROI, and display multiple synchronized windows across your desktop without crashing your system footprint.

The Core Concept: Image Slicing and ROIs

In OpenCV, an image frame isn’t just a visual picture—it is a standard NumPy array. A color frame is a 3D matrix structured by rows, columns, and color channels: [Rows, Columns, Channels] or [Height, Width, Color].

Because it is a standard array, we can use standard Python slicing notation to isolate any rectangular box we want:

ROI = frame[rowstart : rowend,  colstart : colend]

The .copy() Trap

When you slice a piece of an array in Python like ROI = frame[0:100, 0:100], Python does not create a new image in your RAM. It creates a view or a pointer back to the original frame. If you modify pixels inside that ROI, you will accidentally alter your original main camera frame!

To isolate a region and modify it independently without bleeding back into your primary frame, you must explicitly use the .copy() method:

Below is the complete code script we built during the video tutorial. Copy this code exactly into your Python environment, verify your geometry setups, and run it.

Homework Assignment

Alright, it is time to earn your stripes and see if you can fly with the big dogs. Your homework assignment is to take this foundation and build a dynamic tracking target box using the array geometry principles we just learned.

  1. Create a single main camera window (640 x 360).

  2. Draw an independent rectangular ROI box that starts directly in the dead center of the screen.

  3. Using your keyboard parameters (cv2.waitKey), program the system so that using the Arrow Keys (or ‘i’, ‘j’, ‘k’, ‘l’) smoothly updates variables to move the ROI box dynamically around the screen in real-time.

  4. Crucial Constraint: Do not let your boundary indices drift off the array! You must write conditional boundaries so that if your moving target hits the edge of your $640 \times 360$ boundary layout, it locks at the frame border and prevents an out-of-bounds index crash.

  5. In a separate output window, display only the contents of the moving target box in real-time grayscaled format.

Grab your morning coffee, fire up your code editor, write the script from scratch, and do not copy-paste code you don’t understand. Leave a link to your homework solution video in the YouTube comments section so I can see your progress!

AI On the Edge

AI on the Edge LESSON 22: Understanding Pictures and Video Frames as a Data Structure

Hey guys, Paul McWhorter here with TopTechBoy.com, and today we are diving into the heart of computer vision. We’ve been playing around with getting images from the camera, but have you ever stopped to actually look at what a picture is when it’s inside your computer’s memory?

If you want to be a master of AI on the Edge, you have to stop thinking about images as “pictures” and start seeing them as what they really are: a massive, organized grid of numbers.

What is a Picture, Really?

In this lesson, we are peeling back the curtain on how OpenCV and Python handle video frames. When we call piCam.capture_array(), we aren’t just taking a snapshot; we are pulling a data array into memory.

Think of it like a giant spreadsheet where every single cell is a pixel.

  • Dimensions: Your image has a width and a height, which correspond to the number of rows and columns in that array. It is important to remember the row designator comes first, then the column, [ R, C]

  • The Depth (The RGB Channels): It’s not just a flat 2D grid! Each “cell” in that grid is actually a little sub-array containing three values: Red, Green, and Blue. That is why we call it a 3D data structure.

Manipulating Data, Not Just Pixels

The magic happens when you realize you can reach into that array and change those numbers directly.

In the code we developed today, we aren’t just displaying video; we are performing data science on video frames. We explored how to:

  1. Access individual pixels: By referencing specific coordinates in our frame array, we can pull out the color data for a single spot.

  2. Draw shapes by modifying arrays: Notice how we don’t need a “draw square” function to put a box on the screen? We simply tell a slice of that array to equal [0, 0, 255]. We are literally changing the color values of those pixels to solid red.

  3. Regions of Interest (ROI): This is critical for AI. You don’t always need to look at the whole frame. We learned how to “slice” the array to isolate a Region of Interest. By carving out a smaller piece of that memory, we can perform operations—like converting to grayscale—on just that section, which saves a massive amount of processing power.

Why Does This Matter?

If you want to build a robot that recognizes objects or tracks faces, you need to understand this structure. AI models don’t “see” a cat; they see a mathematical representation of that cat’s pixel values. By learning how to slice, manipulate, and convert these arrays, you are learning the fundamental language of machine learning.

We are building the foundation here, folks. Once you get comfortable with how to manipulate these arrays, we are going to start doing some really cool stuff with image processing and filtering.

Dive into that code, change those array values, and see what happens when you mess with the dimensions! Don’t just run it—experiment with it.

I’ll see you guys in the next lesson!

In this lesson we developed the following code:

 

AI On the Edge, Tutorial

AI on the Edge LESSON 21: Managing Multiple Windows in OpenCV on the Raspberry Pi

Hey everyone, Paul McWhorter here!

Welcome back to the AI on the Edge series!

In today’s lesson, we’re going to take an important next step in computer vision. We’re going to learn how to create, position, resize, and manage multiple windows at the same time using OpenCV on the Raspberry Pi.

This might sound simple, but it’s actually a very big deal. Once you can comfortably work with multiple windows, you can start building much more powerful vision applications — like having a main camera view, a processed view, zoomed-in sections, and debug windows all running at once.

In this lesson we create:

  • One large main camera window
  • A smaller color preview
  • A small grayscale version
  • Five tiny grayscale windows stacked on the side

This gives you a clean, organized workspace while the camera is running.

What You Learned in This Lesson

  • How to create multiple named windows with cv2.namedWindow()
  • How to resize windows using cv2.resizeWindow()
  • How to precisely position windows on your screen with cv2.moveWindow()
  • How to work with different resolutions of the same image (full size, half size, quarter size)
  • Converting between color and grayscale while running live video
  • Keeping everything running smoothly with good FPS

Mastering multiple windows is one of those foundational skills that separates basic OpenCV projects from more professional and useful vision systems.

Pro Tip: Play around with the window positions and sizes after you get it working. Try making one window much larger, or experiment with different layouts. This is your workspace — make it comfortable!

Ready for the next step? In the next lesson, we’re going to start doing something really cool — we’ll begin combining live video with drawn graphics and start creating interactive vision projects.

Keep building, keep learning, and I’ll see you in the next video!

In the lesson, we develop the code below: