Tag Archives: AI on the Edge

AI On the Edge, Raspberry Pi

AI on the Edge LESSON 39: Understanding MediaPipe Data Structures

In this video lesson I show you how to understand the data structures returned by MediaPipe. I show you how to peel the data structure back, to get at the useful information.

When you run face detection with MediaPipe, the results object it returns is not a normal dictionary or list. It is a special custom object called SolutionOutputs. The easiest way to explore it is to start by checking the main attribute: results.detections. This is a Python list that contains one entry for every face detected in the current frame. If no faces are found, results.detections will be None or an empty list.

To extract useful information, you loop through results.detections. Each item in that list is a Detection object. From this object, you can access two main things: the confidence score using detection.score[0], and the location data using detection.location_data. Inside location_data, you will find relative_bounding_box (which gives you xmin, ymin, width, and height as values between 0 and 1) and relative_keypoints (a list of 6 facial points such as eyes, nose, and mouth).

The standard method is to first get the frame’s height and width, then multiply the normalized values (like xmin and width) by the actual pixel dimensions of the image to convert them into usable pixel coordinates. You can then use these coordinates with OpenCV functions such as cv2.rectangle() for the box or cv2.circle() for the keypoints.

By using simple print(type()), print(dir()), and print() statements on results, results.detections, and individual detection objects, you can quickly discover the full structure. This step-by-step approach — starting from results → detections → individual detection → location_data — lets you reliably reach all the useful information MediaPipe provides.

Below is the code we developed in the video.

 

 

NVIDIA, NVIDIA Jetson Orin Nano

AI on the NVIDIA Jetson Orin Nano: Adding Text-to-Speech (TTS) with Piper

In this lesson, we are building a local, offline voice pipeline using Piper. This engine runs natively on our Jetson Orin Nano hardware, providing fast and natural speech without needing an internet connection. To keep this simple, we will install everything into one specific folder so the software can easily find its own files.

Step 1: System Prep & Piper Installation

Open your terminal and run these commands one by one to create the workspace and download the required files. We are placing everything into the same directory to ensure the AI engine can always find the voice model.

Step 2: Identify Your Audio Device

Because every setup is different, we need to tell the system which speaker to use. Run the following command in your terminal:

Look through the list for your speaker. You will see something like card 0 and device 0. If your card is 0 and device is 0, your identifier is plughw:0,0. You will use these numbers in the Python script below.

Step 3: The Python Pipeline Script

Create a new Python file and paste the code below. Because we installed everything into the same folder, this script will find the files immediately.

Step 4: Customizing Your Voice

Piper has dozens of voices available. To see the full library, visit the Piper Voices Repository. Download the .onnx and .onnx.json files for your preferred voice, place them in the ~/voiceAssistant/piper/piper/ folder, and update the modelPath variable in your script.

Homework: The Talking Echo Bot

Your assignment is to play around with different voice models, and choose several that you like the best. Then modify the Python script so it becomes an interactive “Echo Bot.” Instead of hardcoding the message, use Python’s input() function to ask the user what to say. When the user types a sentence and presses Enter, your script should pipe that text into Piper and speak it back to you. Use a while True: loop to keep the program running so you can continue talking to your computer. Make a video of your working project, and the voices you chose.  In the description in your video, make sure to leave a link back to the video above. That way users can easily click between my video lesson over to your video, and then back to the class video.

NVIDIA

No Cloud. No Internet. No Problem. Two Commands for Local LLM on Jetson Orin Nano

Hey guys, welcome back to the channel. Paul McWhorter here from TopTechBoy.com. Today, we aren’t just messing around with simple circuits or basic scripts—we are going to take that NVIDIA Jetson Orin Nano we rescued from the brink of destruction in the last video, and we are going to turn it into a completely sovereign, local thinking machine.

I don’t know about you, but I am tired of Big Tech telling me I need a credit card, a monthly subscription, and a constant high-speed internet connection just to make an AI model reply to a prompt. Today, we are going to do it completely naked. We are going to cut the cord, pull the ethernet, and run cutting-edge Large Language Models entirely on the local physical silicon of your Jetson Orin Nano.

And we are going to do it in exactly two commands. One to build the engine room, and one to fire up the mind.

Let’s get started.

The Hardware Architecture

Before we drop the code into the terminal, let’s understand exactly what we are building today. We are dealing with three core components working together in a unified system.

  • The Model (The Fuel): This is your raw neural network file (like Google Gemma or Meta Llama). It contains the weights, vocabulary, and potential intelligence. On its own, it’s just a massive, inert file sitting on your storage drive.

  • Ollama (The Engine Room): This is the heavy lifter. Ollama is a local execution framework that takes that raw model file and boots it directly into the Jetson’s unified RAM and CUDA cores. It handles the brutal mathematical calculations required to generate tokens.

  • The Terminal Chat (The Dashboard): This is your interface. It provides the clean command-line text box for you to type your prompts and prints the model’s responses back to you in real time.

The Two-Command Installation

Go ahead and fire up your Jetson Orin Nano, open a fresh terminal window, and get ready to type. Remember: copying and pasting makes you weak. Type these out like a real engineer so your hands learn the muscle memory.

Command 1: Install the Ollama Engine

This command fetches the official automated bootstrapper script from Ollama and executes it locally to configure the background system service on your host OS.

Command 2: Fire Up the Local Model

Once the installation script finishes, your engine room is live. Now, tell Ollama to pull down the optimized 1-billion parameter Google Gemma model and launch an interactive local dialog loop instantly:

The moment you hit enter, your Jetson will download the model weights directly to your local drive, load them straight into the VRAM, and drop you into a clean prompt box. Type a question, hit enter, and watch your local silicon generate answers with zero cloud dependencies.

Choosing the Right Mind for Your Machine

The beautiful part about setting up Ollama is that you aren’t locked into just one model. Different models have different parameter sizes and strengths. On the 8GB Jetson Orin Nano, you want to balance model size against your available hardware headroom to keep your generation speeds crisp.

Here are the verified, hardware-accelerated local models you can experiment with right out of the box:

Launch Command Model Family Size / Parameter Count Best Used For
ollama run gemma3:1b Google Gemma 3 1 Billion Ultra-fast responses, light footprint
ollama run llama3.2:1b Meta Llama 3.2 1 Billion High-efficiency conversational loops
ollama run phi4-mini:3.8b Microsoft Phi-4 3.8 Billion Heavy reasoning and coding logic
ollama run qwen3:4b Alibaba Qwen 3 4 Billion Structured data and multilingual logic
ollama run qwen3.5:4b Alibaba Qwen 3.5 4 Billion Advanced context processing
ollama run gemma3:4b Google Gemma 3 4 Billion Maximum analytical depth on Orin Nano

⚠️ Paul’s Engineering Note on Headroom

The 1B (1-Billion parameter) models are incredibly light and will run at lightning speed on the Orin Nano. If you want to push the machine harder for more complex reasoning, step up to the 3.8B or 4B models. Just keep an eye on your system resources—running a 4B model pushes close to the limits of the Orin Nano’s 8GB unified memory architecture, especially if you are running a heavy graphical desktop environment in the background!

To exit out of any active terminal chat session and return to your standard command prompt, simply type:

Homework Assignment

Alright, you have the hardware running, you have the engine installed, and you know how to switch out the minds of your machine. Now it’s time for your homework.

I want you to install both the gemma3:1b model and the heavier gemma3:4b model on your Jetson Orin Nano. Run them both through a test sequence: ask them to write a simple Python script, and then ask them a complex logic riddle.

I want you to observe the difference in quality of thought versus speed of generation. Is the 4-billion parameter model smart enough to justify the extra computation time on your hardware, or does the 1-billion parameter model give you the snappy responsiveness you need for a real-time edge application?

Leave a comment down under the video showing your results, tell me which model you prefer running natively on your bench, and I will see you guys in the next lesson!

AI On the Edge, Tutorial

AI on the Edge LESSON 14: Control LED Color With Voice Commands on Raspberry Pi 5

In Lesson 14 of AI on the Edge, we’re doing something really fun and powerful — we’re building a voice-controlled RGB LED that listens to you, changes colors on command, and even talks back with some personality! This is true edge AI running 100% locally on your Raspberry Pi with the Fusion HAT. No cloud, no internet, just fast, private, and responsive voice interaction right on your desk.

You simply speak a color — red, green, blue, cyan, magenta, yellow, off, or even quit — and the RGB LED instantly springs to life with beautiful color. But that’s not all. Every time you give a command, the system replies with a fun, playful spoken response using the Piper text-to-speech engine. It turns your Raspberry Pi into a charming little LED companion that feels alive and interactive.In this lesson, you’ll learn how to combine local Speech-to-Text with the STT library and natural-sounding Text-to-Speech with Piper. You’ll master PWM control of a full-color RGB LED through the Fusion HAT, and you’ll see how to use Python threading plus a queue to keep the voice listening running smoothly in the background without ever locking up your main program. The code is clean, well-structured, and includes proper startup greetings, graceful shutdown, and excellent resource cleanup — exactly the kind of solid practices we love in this series.What makes this project extra special is how it brings everything together. You get real-time voice recognition, instant hardware response, and spoken feedback — all happening locally on the edge. It’s fast, it’s private, and it’s incredibly satisfying to watch that LED light up exactly as you command while your Pi chats back at you.

Go ahead and watch the full Lesson 14 video, grab the complete code from the description, and build this project step by step with me. Once you have it running, I want you to play with it! Add new colors, create your own funny responses, or start thinking about how you could combine this voice control with sensors or other hardware in future projects.

This is the kind of hands-on, creative AI application that makes learning so exciting. You’re not just watching — you’re building real, useful skills that put you in the driver’s seat with artificial intelligence.

Fire up that Raspberry Pi, get your Fusion HAT ready, and let’s make some colors shine while the Pi talks back. I can’t wait to see what you create with this one!

Happy building, everyone — I’ll see you in the next lesson!

This is the schematic we are using for the project:

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

This is the code we developed in the video: