In this tutorial I am installing a portable battery on my MechSoul. (A MechSoul is to a robot what a CyberDeck is to a computer) A robot you build, personalize and customize yourself. In this tutorial I am powering my MechSoul with a portable charger I bought online, because it's quicker and safer than designing a custom battery solution as I explain in the video. So instead of designing a PCB I head to my 3D printer to build a battery mount.

If you want to follow along get access to the code and 3D files you can check out the project GitHub

This is a LEGO DUPLO-sized toy train. It started almost a year ago with slightly adjusting someone else's 3D model and a simple circuit diagram and completely rewriting the Arduino code.

It worked for a while. But now I'm changing everything: my own 3D model with a lot of improvements, multiple new I2C modules (a laser sensor instead of an ultrasonic sensor, a color sensor, LEDs moved away from the Arduino pins to an expander with MOSFETs), a battery pack with a BMS and USB charger, a better motor driver and other changes.

The circuit diagram is rather finalized for this version (with a bit of AI help to change the color scheme and make it easier to read - replaced color codes in EasyEDA JSON file). Everything is verified and tested. The Arduino code is almost ready (and there is a lot of code for various features), but the final version will require some calibration and real-life testing by kids. An accelerometer/gyroscope will be added a bit later, I'm yet to choose a module. Any recommendations? The battery pack is ready (posted earlier). Perfboards are soldered: the main one with an Arduino Nano, one with an expander and resistors to control LEDs, and one with an IR receiver.

For a beginner it's a lot of learning: how to build a battery pack, how I2C-bus works with multiple devices, how those devices work with different voltages from 2.8V to 5V, perfboard soldering etc.

The 3D model of the train body is in development (the kids are happy to get multiple prototypes of train parts even though they have no wheels and can't be assembled together)...

Hello everyone this is a follow-up video for the project I

Post a while back where I showed a sample application I.e aurdino on another.

Now I have built the first working version of the application and I know it's far from done but I am working on this.

I would love your support on this project because I don't have any as of now I guess 😭.

Anyways here is the demo of the app hope you like it.

This whole project started when a cool Pixel Clock popped up on my Pinterest feed. Instead of just saving it to a board and forgetting about it, I decided to turn it into reality!

Instead of buying one or ordering pre-made parts, I built custom tools at home

1. modding my 3D printer into a circuit plotter

2. Etched my own pcb boards

3. Custom hotplate station just to assemble the pcbs

4. Custom 3d designed clock stls

Pretty stoked with how a simple Pinterest scroll turned into a real, working project on my desk!

(Holding off on posting links right now, but I'll drop all details/links in the comments later!)

What do you guys think?

Built a Dynamic Fire-Aware Evacuation Guidance System using ESP32 🚨🔥

I’m working on a college-level prototype that tries to solve a problem with normal fire alarms: they can tell you there is a fire, but they don’t tell you which evacuation route is currently the safest.

The idea is to create a small building model divided into different zones.

How it works

The ESP32 monitors the zones using:

🔥 5-channel flame sensor

🌡️ 4 × DS18B20 temperature sensors

💨 MQ-2 smoke sensor

The building is represented as a graph, with rooms/intersections as nodes and paths as edges.

Each path gets a risk value based on the sensor data:

🟢 Clear → low risk

🟡 Warning → higher risk

🔴 Fire/smoke detected → very high risk / blocked

The ESP32 then calculates the safest available route instead of simply choosing the shortest route.

The interesting part

The system continuously monitors the environment.

For example:

Initially, Route A is safe → green LEDs guide the person through Route A.

Fire spreads into Route A.

Sensors detect the new hazard.

The ESP32 updates the hazard map.

The routing algorithm calculates another route.

The LED guidance changes.

The speaker announces the new instructions.

The voice guidance will use a DFPlayer Mini + speaker, with pre-recorded instructions such as:

"Fire detected. Turn right."

"Route blocked. New route. Turn left."

"Continue straight to the exit."

I'm also using sequential LEDs so the person can follow the path visually without having to stop and read a display.

Estimated cost

Around ₹650, excluding the ESP32, speaker and SD card because I already have those

Hey everyone
I've been working on a local, self-hosted smart lock using and Esp32 microcontroler and a custom php backend. The hardest part of design it was the actual modeling since im more of a coder guy as a senior in highschool.

I finaly created something that looked decent compact and that could fit the breadboard and whole wiring inside.

In the photo there is currently just the login page.
I designed it using fusion 360 autocad.
If anyone wants to print it for their smart lock that they are making themself or just curiousity of the code and setup/ guide on how to build a similar setup to your enginering imagination https://smartlock.lemonsqueezy.com/checkout/buy/c7858731-881d-4815-bb05-70373437e4da

Two 18650 li-ion batteries + 2s BMS + LS-LISC-V3 8.4V USB charger + JST SM output. The battery pack will be mounted inside of a 3D-printed model with USB port accessible through a hole.

2s battery pack sounds easy, but:

1. I had no experience
2. I have no spot welder and I don't feel soldering batteries is what I should do
3. those battery holders that are being sold everywhere make no sense - two thin wires and not really designed for replacing wires or adding a third wire; I tried to buy a different battery holder, but they sent me not what was on the photos anyway;

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

Added automatic fretting calibration to my guitar robot.
It uses force feedback to find the right position automatically, so there’s no need to manually tune every servo position.
One tap, calibrate, then play.

In this tutorial we go over how to control your MechSoul with Bluetooth. What is a MechSoul? A MechSoul is to a robot, what a CyberDeck is to a computer. It's a robot that you build, customize, and personalize yourself. It's the freedom of owning your own code, hardware, and having the right to build and repair it. And it's the pride of creativity, skill, and self expression.

In this part 2 in Arduino IDE we combine the Raspberry Pi Pico's board manager's SerialBLE example with the Serial_Control example in Takamori Robot's HIRO library to control your robot over Bluetooth. To follow along with our code and reference material check out the tutorial GitHub.

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.

This started out as an attempt to make a physical implementation of one of those in-game type of puzzles. But it turned into a diabolical color combination lock. So you have to know the color sequence to begin with. It moves the colors around and throws in false choices, so if someone is watching you enter the combination they won't be able to duplicate it.

The test panel ended up looking kind of cool, it's got good tactile feel, and it's fun to play with.

More pictures, 3D print files, and Arduino source code is here: Color Combination Lock

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

I made an Arduino project where LEDs just rotate in a circle. It looks really cool, although the wires are a bit untidy right now. I will try to clean up the cable management in the next version.

I built a desk gadget powered by an ESP32 that combines touch activation with 6 rotating TFT displays, and I call it Roulette. It's open source — I've shared the code on my GitHub for anyone who'd like to build their own.

🔗 Links:
💾 SOURCE CODE:
https://github.com/yumobuilds/Yumo-Roulette

roulette wheel with six round 240x240 displays, each showing something different:

SD card photo slideshow
Live YouTube channel stats
Live TikTok stats
Crypto ticker
Live weather
Internal temp & humidity (AHT10 sensor)

⚙️ The floating spin mechanic:
The whole assembly rotates on an upside-down DC motor. Everything sits on a frame, and that frame is mounted directly onto the motor's body — not the shaft. The motor shaft itself is inserted into a drill chuck from the reverse side, the opposite way a drill bit would normally go in. So instead of the shaft driving an external bit, it's anchored inside the chuck while the motor body (carrying the frame and wheel) spins around it. The result: there's no visible axle or support arm, so the whole thing looks like it's floating and rotating on its own.

Touch the capacitive sensor and an N20 motor spins the wheel for a set duration — one touch,
one spin. A NeoPixel status LED fades through colors while it boots and flashes when you touch the sensor..

🔧 Hardware:

• ESP32 Wroom
• 6x GC9A01 round 240x240 displays (shared SPI bus)
• DRV8833 motor driver + N20 DC motor
• TTP223 capacitive touch module
• AHT10 temp/humidity sensor
• MicroSD card module (own SPI bus)
• NeoPixel/RGB status LED

💻 Software:

• ESP32
• WiFi captive portal for setup (no hardcoded credentials)
• YouTube Data API v3, TikTok stats via RapidAPI, OpenWeatherMap
• TJpg_Decoder for on-device JPEG decoding from SD

board : LOLIN(WEMOS) D1 R2 & mini
sensors :
AHTX0 + BMP280 ( I2C )
MHZ-19E
SSD1306 ( I2C )

code + how connected :
https://github.com/IDEA0923/air_monitor

This is part 1 in tutorial is about building your won MechSoul(Mechanical Soul). A MechSoul is to a robot what a CyberDeck is to a computer. A robot that you build yourself as a form of self-expression as well as freedom of owning your own hardware and code.

In this tutorial we are setting up a MechSoul seed(a robot base to be customized into a MechSoul. ) assembling it and setting up Arduino IDE. You can find assembly and setup resources as well as other resources in our tutorial github at by clicking here.

I kept running into the same problem when combining multiple I2C sensors: finding the address is one thing, but checking whether several devices can actually coexist on the same bus is another.

So I built a small free tool that does both:

• Search common I2C device addresses
• Search by hexadecimal address
• Select multiple devices
• Detect address conflicts
• Find an alternative address configuration when possible
• Suggest solutions such as another I2C bus or an I2C multiplexer

For example, MPU6050 + DS3231 can both use 0x68, so the tool detects the conflict and can suggest using 0x69 for the MPU6050 when supported.

It's open source and runs entirely in the browser.

GitHub:
https://github.com/webzf/i2c-address-compatibility-checker

Online tool:
https://embeddednerd.com/tools/i2c-address-lookup/

I'd be interested in feedback, especially on other devices or I2C features that would be useful to add.

So hi everyone this is my first time posting on this place.

I don't usually post things 😞.

So I always wonder why I have to buy all these extra sensors and stuff when my phone already has all these sensors.

So I am building an Android based project which can combine both Arduino and Android together. This thing is not present out there till now I am going to make it full customisable and Full programmable.

The two biggest challenges I have already fixed which are

1. Compiling the code directly on Android device

2. The usb serial communication.

So I will build this application I wanted some feedback on this.

In the below project I have shown the motor rotation + led blink.

Quaddle, an open source quadruped based on OpenCat, runs its firmware on Arduino C++ — this clip shows a webcam pose-tracking rig mapping one person's body movements live onto two of them simultaneously (Scout and Buddy), no AI policy involved, just real-time human control translated into servo commands.

OpenCat creator RZ Li drove them head-first into each other on purpose, raced them, and taught it a few moves along the way — a little awkward at first, but it only takes a few minutes before it starts picking them up. It's a genuinely fun weekend build, too — basically Wii Play: Motion with a real robot on the other end — and affordable enough that this isn't just a research-budget project.

Anyone else piping real-time sensor/vision data into Arduino-controlled servos — what's your approach to keeping latency low?

And just for fun — what move would you want to teach Quaddle, if you built one?

I'm working on a project that explores the idea of accessing real embedded hardware remotely through a web browser.

The goal is to let students experiment with boards such as Arduino, ESP32 and STM32 without having to own all the hardware themselves.

I'm still at the exploration stage, so I'm trying to understand what would actually be useful.

If you could access a real embedded board remotely, what would you want to experiment with?

For example:

• GPIO
• UART / I2C / SPI
• Sensors
• PWM
• Debugging
• Logic analyzer
• Oscilloscope

What would make a remote lab genuinely useful to you?

I hope you all like it! :)

ESP32 CYD used

M5stack CardKB for the keyboard

and a bunch of other sensors including environmental readouts, a compass, IR blaster/receiver, and more

https://youtu.be/FdoXedWSMrI?si=opj3zrQsXDNEAfwy

Hey guys,

I just recently relocated from a third floor apartment to a first floor because my dogs are getting elderly and having them walk down 3 flights of stairs to relieve themselves isn’t viable.

I looked at sliding door doggy doors but they don’t fit what I need or want. The closest I found is a Wayzn but even that is a large purchase. I want something that lets me open the sliding door for them remotely via an app for when I’m not home. I have a 3d printer and minimal knowledge of programming. Can someone direct me to the best place where I can learn to make something like that?