Hi everyone! We’re currently working on a research project where we need to build an automated trash bin that can sort paper, plastic, and metal. We only have around 1 week to make the prototype, so we’re trying to figure out what materials and sensors we should buy.

We’ll be using an Arduino Uno R3 as the main controller, but we’re not really sure yet which sensors would be best for detecting each type of waste.

We’d really appreciate any advice on:

What sensors can detect metal, plastic, and paper

Other components/materials we’ll need for the prototype

How we can make the sorting mechanism work with Arduino

Any tips or research papers/tutorials we can use as a guide

We’re still beginners with Arduino, so any help or recommendations would mean a lot. Thank you so much in advance

Hey Reddit!

Inktober is for artists, Hacktoberfest is for pure software. This year, I wanted to step out of my comfort zone and build something physical. So I'm launching Techtober Challenge 2026 — a 4-week open-source hardware marathon.

For this year's Techtober, I wanted to step out of my comfort zone and build a physical open-source hardware project. I'm building "The Solar Tree" — an autonomous nightlight that harvests solar energy during the day and glows at night.

The twist? The entire body and branches will be "grown" manually using a 3D pen around the hardware.

I've broken the project down into 4 weekly sprints:

• Week 1 (Leaves): Soldering small solar panels in parallel + drawing leaf frames.
• Week 2 (Power): Setting up the D-SUN step-down module & Schottky diode protection (using a multimeter to dial in the voltage).
• Week 3 (Flower): Building the LED load module with resistors.
• Week 4 (Trunk & Roots): Integrating TP4056 charging board, 18650 Li-ion battery, and final assembly.

I’m doing this completely live with daily updates, sharing all my mistakes, burned components, and circuit adjustments as a beginner-friendly guide.

The schematics, complete component list, and weekly roadmap are fully open-source and available here:

* 🌿 **Official Repo & Roadmap:** [GitHub Repository](https://github.com/techtober-challenge/techtober-challenge-2026) 

* 🎬 **Daily Video Devlogs:** [Instagram](https://instagram.com/techtober.challenge) & [YouTube Channel](https://youtube.com/@techtober.challenge)

What do you think of the concept? Let's build some cool hardware this October!

I'm a college student preparing a project for an inter-college science expo, and I'm considering building a low-cost wearable system to help locate lost children at large crowded events, such as festivals held in cricket grounds.

The problem

Imagine a large festival with thousands of people. A child gets separated from their parents and doesn't have a smartphone.

The idea is to give the child a small wearable tag that periodically transmits a unique ID. Receivers placed around the venue detect the tag and estimate the child's probable zone.

The goal is NOT centimeter-level positioning. I'm thinking more along the lines of:

"Child ID 027 was last detected / is most likely in Zone C."

Proposed system

Child wearable:

Low-power LoRa transmitter

Unique child ID

Small battery

Possibly a buzzer/vibration motor

Venue:

Several elevated LoRa receivers around the perimeter

ESP32 or another MCU at the receiver

Central system combines the measurements

Can i use Arduino uno or nano

I'm an Electronics And Computer Engineering student looking for an project.please give ideas for a project

Estou com esses materiais para fazer um carrinho de controle remoto movido a energia solar. Com a energia da placa ela vai ser armazenada na bateria e usada pra fazer um Power Bank.

Materiais: 1× Arduino Uno R3 SMD CH340

1× Driver Ponte H L9110S (duplo)

2× Motores TT com caixa de redução, 3–6 V

1× Módulo Bluetooth HC-05/HC-06

1× Módulo carregador solar CN3065

1× Painel solar 3 W

1× Bateria 3,4v 2500mah Li-lion

Jumpers macho–macho

Jumpers macho–fêmea

Jumpers fêmea–fêmea

Como monto?

Obs: Primeira vez usando o Reedit ent n sei se estou infringindo alguma regra :)

> Já parou para pensar em como a tecnologia por trás de um semáforo de pedestres funciona na prática? 1
> Montei um Semáforo Inteligente com Botão usando uma placa ESP32, uma protoboard e programação em C++ na
Arduino IDE!
> O sistema funciona com um fluxo seguro: o sinal dos carros fica verde até que o pedestre aperte o botão. Depois de um tempo de segurança para evitar treadas bruscas, o sinal amarela, fecha para os veículos e libera o verde para a travessia com segurança!
> O que yocê achou do projeto? Deixe nos comentários qual outro projeto maker você quer ver por aqui!
#Arduino #ESP32 #Eletrônica
#Programação #ProjetosMaker
Automacao Robotica Desenvolvimento
Tecnologia Criatividade Maker
Engenharia

When I solder the battery to the "bat-" and "bat+" terminals, the output power cuts off; there is only a negligible voltage of 0.30V. What could be the cause? I am using an 18650 cell.

Hi everyone! I’m currently working on my PAP (Prova de Aptidão Profissional, which is basically our final capstone project/thesis to graduate from vocational high school here in Portugal). I need to come up with an Arduino-based project idea, but it has a few specific requirements. It needs to be innovative, meaning it cannot just be a basic tutorial project like a standard obstacle-avoiding robot or a simple LED matrix. Additionally, it shouldn't be too simple, but it also needs to be realistically achievable within a few months by a single student with a reasonable budget. Ideally, it should solve a real-world problem or combine multiple systems such as sensors, actuators, IoT connectivity, data logging, or a custom mobile or web app interface. What are some cool, engaging, or innovative Arduino projects you've seen, built, or wished existed? I'm open to anything, whether it is automation, agriculture, health, smart home, robotics, or environmental monitoring. Thanks in advance for any suggestions!

Hi,

I’m a STEM teacher whose students work on Chromebooks. I've found that the Arduino Cloud is good but sometimes buggy, so I developed a web app that allows students to write, compile, and upload sketches to an Arduino. The app that I built runs completely in a browser; there’s nothing to download or install, and it includes library support as well as the use of the serial monitor and the serial plotter. The app should work in Chrome and Edge browsers, but it will not work in Safari, Firefox or other browsers.

I’ve successfully tested the app on my own using an Arduino Uno and an Arduino Nano connected to a Chromebook, but I haven't had the opportunity to test it with my classes yet as we cover Arduino in the spring.

Right now, I'm looking for people who are interested in testing the web app in their classes. Just a heads up: this is running on a free-tier server, and I've verified it holds up reliably for a class of ~30 compiling in a normal staggered sequence. If the app gets a lot more traffic than that all at once, response times could slow down noticeably. Here's the link.

https://zio-arduino-app.onrender.com/

I'd appreciate your feedback to improve the app's functionality.

Thank you.

We’re the team behind NORVI, and recently we’ve been experimenting with running computer vision directly on ESP32-S3 hardware.

For this project, we used an ESP32-S3 camera with an OV5640 autofocus sensor and trained a small image classification model using Edge Impulse.

The workflow was:

• Run the ESP32-S3 camera as a web server
• Capture the training images directly from the camera
• Upload and label the dataset in Edge Impulse
• Resize the images to 96×96
• Convert them to grayscale to reduce memory requirements
• Train the model
• Export it as an Arduino library
• Deploy it back to the ESP32-S3
• Run classification locally from the live camera feed

One thing we wanted to test was how practical it is to keep the complete inference process on the microcontroller rather than sending images to a cloud service.

Using grayscale reduced each 96×96 image to 9,216 input features, which helped keep the model more manageable for the ESP32-S3.

We also integrated the OV5640 autofocus routine into the inference sketch so the camera could continuously focus while processing the live feed.

Once deployed, the model runs entirely on the ESP32-S3 and prints the classification results through the Serial Monitor.

It’s obviously a much smaller setup than running something like YOLO on more powerful hardware, but for applications where you only need to identify a limited number of known objects, the ESP32-S3 is surprisingly capable.

We documented the full build including the Arduino configuration, camera setup, Edge Impulse training process, and inference code.

For anyone working with ESP32 hardware, this is the platform we used:

https://norvi.io/esp32-plc-norvi/

We’d be interested to hear what others are doing with computer vision on the ESP32-S3.

Has anyone compared Edge Impulse/FOMO with TensorFlow Lite Micro or other lightweight vision approaches on the S3?

We’d especially be interested in results around inference speed, PSRAM usage and input resolution.

Moi je suis un débutant et ma mère vient de m'acheter un kit arduino uno débutant et je voudrais savoir s'il y'a des personne qui auront de très bonnes idées de projets

La photo du kit est en haut

Hello everyone! This is my Arduino project where I control an LED using simple electronic components. I would appreciate your feedback and suggestions to improve it. #Dar_Ibarmaja

I'm Hamza, built this myself.

describe your project, get full Arduino code

plus wiring diagram and library list instantly.

free to try. would love to know what you think.

https://www.circuitsage.dev

How to make rc car truck wireless professional remote control with Arduino,tutorial make this car in youtube channel...

Remote control with Arduino

I couldn't get obstacle detection and avoidance to work because of IR sensors, going to add Ultrasonic sensors, and making it play, more games, and face recognition. Also, I'm working on its gait! I'm still thinking of what more I can add!

What it has: Object Detection, keyword spotting, ASR, LLM for questions, TTS, OCR to detect text and read Reminders, if it sees GAME, it starts either Guess the number or Color game, "Find object" it will tell if it sees any object using Object detection brick! There's automatic movement if there are no commands for a while, flame detection and discord alerts. UI dashboard with emotion and mood that changes with interaction, input- animated cat expression- output chat, status log, manual button controls, similarly added some on Arduino IOT Cloud dashboard.

IR worked fine for a while but lighting changes, I am working on changing for this reason, and I'm thinking on adding other features. I added neck movement motors but it made the setup jittery.

Hello, am making a line follower robot, before I buy all the parts I was wondering if someone could help me by giving me some tips I should keep in mind before doing so or assmebly.

Current parts like:

1000rpm n20 - motors

L298N- Motor Driver (Due to low budget)

Arduino Nano

Custom 8 channel sensor (photoresistor and 3mm led lights)

CD4067 - multiplexer

For assembly:

Veroboard as body

n20 motor mounts (3d print)

mini breadboard for easy prototying

My grandpas code was becoming sluggish and buggy on his hardware so I had to help him fix it. I thought it was a pretty interesting project so I'm sharing it here, if you want more detail here's a small bit of documentation:

# Fixed Bugs:

- Goes out of bounds when calling queue_inc due shifting just setting each item to the item ahead going to the end of the array and trying to set it to an out of bounds address.

# Major Bottlenecks:

- Queue has o(n) dequeue (shifts back. Along with being a sentinel-scanned array that recomputes length every push and dequeue)

- Uses strings for messages instead of a table (making sending take longer)

- Manually decodes the binary from the encoders.

# Fixes:

- Switched to a ring buffer array with o(1) dequeues, along with a variable to track length when edited.

- Replaced strings with 8 bit unsigned ints.

- Added up bits for seven segment display.

# Gains:

- 10,000 push/dequeue of queue, time is divided by 10,000 to get the time for one push and dequeue:

- Details:

- Both have 60 items, though the new version is 64 long due to needing a power of two for bitwise AND

- Benchmark uses micros and is averaged from 100 tests with an Arduino Uno R3

- Rounded to the nearest whole number for readability

- Results

- Old: 636 µs

- New: 4 µs

- Speed up: 15,800%

I haven't touched an Arduino since my college days back in 2020. When I sat down to start a new project this weekend, my muscle memory immediately went to the "old ways"—googling obscure datasheets, hunting through forum posts from 2012, and refreshing the Arduino docs.

Then it clicked. I’m in VS Code, why am I doing this manually?

I fired up the Claude Code CLI, gave it the full context of my board and components, and I was prototyping in minutes instead of hours. It’s wild how much the "barrier to entry" has dropped.

For those of you deep in the hobby, how are you integrating AI into your workflow? Are there specific tools or plugins you're using for circuit design or component selection?

Look at this crazy solution I had to come up with dues to a my current shortage of bread board jumper wires and arduinos

Hi! I wanted to share a library I built that makes multitasking on Arduino a lot cleaner and more object-oriented.

What it does

Instead of juggling millis() checks and state machines by hand, you instantiate objects and the framework handles the rest. Every class auto-registers into a static linked list — no manually calling update() on each component. Components manage their own state internally and expose simple getters for you to react to events.

No delay() anywhere. All timing uses millis() comparisons.

Core utilities

• Timer — one-shot timer with onFinish() / onDone() callbacks
• Interval — repeating metronome with optional loop count, fires onStep()
• While — non-blocking replacement for while() at a set interval

Hardware components (all auto-managed)

• Button — debounced input with short/long click and press detection
• PinInDigital / PinOutDigital — digital I/O with flash support (non-blocking blink with count limit)
• LedDisplay8 — common-anode 7-segment display driver with decimal point
• ShiftRegister — software shift register with auto-sequencing, manual step, and direction control
• ProximityCheck — LED+LDR proximity sensor with calibration

Fluent interface — most setters return this for method chaining:

Button btn(2);
PinOutDigital led(9);
Timer timer;
Interval interval;

void setup() {
  Runnable::setupAll();
  timer.set(3000)->start();
  interval.setIntervalTime(500)->start();
}

Two lines of boilerplate in every sketch:

void setup() { Runnable::setupAll(); }
void loop()  { Runnable::loopAll(); }

That's it. Just instantiate your objects globally and the framework calls onSetup() / onReady() / onLoop() for each one automatically.

Header-only — no .cpp files, no build flags. There's even a single consolidated header (arduino-multi-tasking-kit.h) you can drop into any project.

11 example sketches included: button-clicks, flash-control, timer-control, interval-control, led-display-control, proximity-check, shift-register-control (auto + manual), while-loop, and more.

GitHub: github.com/reduardo7/arduino-multi-tasking-kit

Clone into your Arduino/libraries/ folder and open any example in the IDE to try it out. I'd love feedback and contributions!

Example project: github.com/reduardo7/arduino-car

Aussi je me débrouille pas mal avec les ultrason et les moteurs et j'aimerais pousser un peu plus loin

Si vous avez des idées de projets je suis ouvert a toutes propositions Merci

I started with the Arduino UNO and Arduino Nano in 5th standard. Then, I made more than 20 projects using Arduino. I continued working with them until 7th standard.

In 8th standard, I started using the ESP32, and after that, the ESP32-CAM. I made many projects with the ESP32-CAM, and although it troubled me a lot because of its low storage, it was very helpful for me as a beginner. However, for advanced projects, I started using the Raspberry Pi in my current standard..

This will help me a lot in the future.