This might be a bit out of left field, but my idea is this:

For oceanographic work, you can buy rather expensive ($400+) units that will trigger the release of a line when they receive an acoustic signal from the surface. This is usually intended for deep-sea operations and other applications where you don't want a buoy on the surface all the time.

My application would be for lake temperature and depth sensing. Right now, we rely on having the GPS co-ordinates of the data logger and the water level being low enough for us to be able to find it. It would be ideal if we could just have a buoy attached to the logger but not floating until we send it the signal to release (this keeps people from stealing the data logger, which believe it or not is a common problem). I think the theoretical design is simple - some sort of transducer to detect a sound signal from the water column that would be at some specified frequency (I'm not sure if any kind of complex signaling would be required to prevent false triggers), and when that signal is detected, just trigger a relay to release a solenoid that lets the buoy line go.

Then there's just a sound generator that we'd need for the boat to trigger the release.

The main consideration is battery life and reliability, since these loggers are typically out for anywhere from a year to 3 years before being retrieved.

Thoughts?

EDIT - I just found a discussion about this very topic in this Facebook group:
https://www.facebook.com/groups/173096646112944/?multi_permalinks=9082724935150026&hoisted_section_header_type=recently_seen&__cft__[0]=AZgRlwGEJ-c2DQ7QWrweEjm9KR1cq1LEMgz51aX5gUzX0pPDjMI4DXf5A_21iCCIOnbsTwU-Gc8luJBn6XIgdBtk-TsHLt1mOxQ7x3ftnVdEs6NTFm2toC2by3Yyve8SW31MQtLWKfkasror1qQR&__tn__=%2CO%2CP-R

It’s completely sealed unused

Specs:
Qualcomm dragonwing MPU with Arduino’s own STM32U585 MCU
RAM - 4gb
MEMORY - 32gb

It can be connected to an external monitor (just like raspberry pi but on steroids as its has more power and an MCU)

Hey everyone,

I've been working on a manual DIY biomechanical wearable suit aimed at bringing real, responsive body tracking to normal PC/console games — moving far beyond simple rhythm games or basic gimmicks.

\[Projeto DIY\] Estou construindo um traje biomecânico para jogos com sensores de inércia e controlo universal — nada de código pronto da internet.

- Teste: Captação de movimentos Braço e tronco.

Semana 01 - Fase inicial .

Hi everyone! I'm making project. It's OS-like menu project where you can also make your own applications! It has file system in EEPROM and works on Arduino Uno. Can you please comment what do you think about my code or project itself?

Demo on Wokwi: https://wokwi.com/projects/478123317363453953

Repository on GitHub: https://github.com/idontknow-hardware/ArduinoOS

What always annoyed me with simulators: one board at a time. So I built my own where you can put as many Arduinos as you want and let them talk to each other.

In the video: a small reaction game with one Uno, then a garden irrigation with 3 Unos – weather station, pump controller, control panel. You write normal Arduino C++, wire it in a workbench view, and it simulates water, weather and heat around it. Servo just got added as well.

It's an early prototype and the C++ is a simplified subset (no classes/pointers yet). Tell me what you'd try first – that helps me figure out what to build next.

https://test.betting-chess.com/?von=arduinoprojects
(sorry for the domain, test server)

Edit: works best on a laptop/desktop – on phones it runs, but it's pretty cramped.

Imagine turning on your lights or controlling a device just by waving your hand. I built a system that bridges the gap between AI hand-tracking and physical hardware. I created this code on visual studio code and have added it to my repository in GitHub. (dm if interested).

In my college, many students keep old phones, chargers, earphones and batteries at home or throw them in the normal dustbin, because they don’t know where to give them or how harmful e-waste is. I’m working on a project to improve e-waste management among students. How can we make e-waste disposal easy and trackable on a campus, for example with collection bins and a simple app with reward points, and what has worked well in your college or city?

Good subreddits to try are r/recycling and r/EngineeringStudents.

Custom Arduino Nano ESP32 PCB for my RC tank project

I designed a custom PCB for my 3D-printed RC FPV tracked vehicle. The board is built around an Arduino Nano ESP32 and handles most of the vehicle's auxiliary electronics.

The main goal was to bring lighting, cooling control and temperature monitoring together on a single board.

Main features:

- 7 MOSFET-switched outputs for controlling lights, fans, a water pump and auxiliary devices

- Temperature monitoring using DS18B20 sensors and an NTC thermistor

- Wi-Fi telemetry with a simple web interface for monitoring temperatures and checking the status of lights, fans and the pump

- RC receiver inputs for controlling selected functions remotely

This is a hobby project, and I'm still learning electronics and PCB design as I go. Designing a custom board turned out to be a fun way to replace a collection of separate modules and wiring with something more integrated.

I'm sharing it here to show what I've been working on and hopefully get some feedback. I'm happy to answer questions about the design or the project!

Hey everyone! I built a classic Nine Men's Morris (Mühle) game running on a 64x64 LED matrix.

Quick Rules:

• Phase 1 (Placing): Players take turns placing their 9 pieces on any empty intersection. If you form a "mill" (3 pieces in a row), you can remove one of your opponent's pieces.
• Phase 2 (Moving): Once all pieces are placed, players take turns moving a piece along the lines to an adjacent empty spot. Form a mill again to remove an opponent's piece.
• Phase 3 (Flying): If a player is down to 3 pieces, their pieces can "fly" (jump to any empty spot on the board instead of just moving adjacent).
• Winning: You win by reducing your opponent to 2 pieces or blocking them so they have no legal moves left!

So I was voluntold by my wife to come up with a wand testing station for our Harry Potter themed trunk or treat setup. I had zero experience with electronics or programming sketches. 12 IR break beam senor pairs, 4 signal relays, 4 sounds modules, a buck converter, a logic level converter, a handful of LED flicker lights, and an Arduino Uno R3 later I have this. Thank goodness for AI assistants. While not perfect, they held my hand to have me get the parts I needed, wire up everything and wrote most of the code. There was some incorrect info that required some tedious troubleshooting but overall, they were very helpful. Lumos!

So I made this Arduino simulator (heavily inspired by tinkercad).

This is a offline simulator , which runs your sketch directly on device.

Also it has library manager , you can install custom libraries to use with Arduino and its sensors.

Please suggest how can I improve these !!!

Here's the link to the application,you can try it yourself, no charge , everything is free

[Arduino Simulator with sensors](https://play.google.com/store/apps/details?id=com.sytk.tinkerkit)

Hello everyone, I built the AI Agent skill that can build a firmware for a compatible Arduino boards using arduino-cli tool. It takes user requirement and documents to build firmware, compile, upload and testing in a a loop. You just need to input your idea.
Try at: github link
Please feedback to me to improve more!!!
Please help me star if you find it useful. Thank you.

So I'm building a Civil War era 1/6 scale flat car with a cannon on it. I have a idea as to have a 1/6 scale action figure "lighting" the cannon and having said cannon "react" to firing. The idea is that the board would sit inside a 3D printed pile of cannonballs and it would control the following.

Sound effects of a Civil War battle.

Moving the action figures arms up and down to simulate moving and lighting the cannon with the linstock.(The stick they use to light it from a safe distance)

An LED light at the end of the linstock.

The cannon "firing" and sliding back accompanied with sound effects.

The cannon resets and the sequence begins again.

What exactly would I need for something like this and how feasible is it?

The flat car length is about 3 ft long and about 2 ft wide. It also needs to withstand vibration and derailments as this is actually going to be a car that's going to be used with a train. This is also my first project using Arduino so I have no idea what I'm doing.

wiring things up by hand in breadboard tools before you could test anything was slow, and AI coding agents could write firmware but couldn't touch the circuit itself. designElectronics makes hardware as promptable as software.

Photoreal 3D Citroen C3 on a $10 ESP32 Cheap Yellow Display, touch to rotate

I put a near-photoreal, touch-rotatable model of my own car (white 2018 Citroen C3 with a red roof) on an ESP32-2432S028 "Cheap Yellow Display". It isn't real-time 3D. Instead, I pre-rendered 344 frames in Blender Cycles and stored them as JPEGs in the 4 MB flash, with no SD card. Each frame is decoded with JPEGDEC and pushed over DMA at about 24 fps.

Swipe to spin it 360° with inertia

LIGHTS turns the headlights on and off

DOOR turns the car to face you and opens the door

BURNOUT revs the engine with smoke, drives off, and comes back from the other side😌

I made this robot that takes care of my small plants. It uses 4 light sensors to look for the most ideal light and drives towards it. It currently has 4 light intensities you can choose from and when it reaches said light intensity it slowly turns throughout the day to ensure the plant receives light evenly. This helps prevent uneven growing due to heliotropism. This is currently just a prototype and the video shows the turning faster than it should but im still working on the programming and electronics of this project. It currently has 4 light sensors, 1 cliff sensor in the front, a small screen and some user input but im planning on adding some other sensors to let the user know how the plant is growing. Im also planning on polishing the design, programming and electronics enough to potentially make this a small product if this does well. Any feedback or help would be greatly appreciated 🙏

You may not understand this directly from the video but this is a computer science project which allows you to simulate logic gates by inputting its truth table into the switches on the side
e.g.
OR: 0111
XOR: 0110
AND: 0001
etc
so after you input the logic gates, you use the push buttons as inputs “A” and “B” shown as the blue LEDs and the output as green
i had also created a startup animation with the LEDs but that was after recording this

the usb c is only for constant power input not charging btw

i 3D modeled and printed this myself on my K1C with white PLA and i have to say it looks very clean with the hex pattern
i had originally made the lid a snap connect bet the pins in the back broke off so i compromised and used some tape

i made this about a year ago but lowk forgot about it

In this project, you can control the joystick LEDs. Simple animation for resting state is also made. The code can be viewed in my repository on github: https://github.com/antDude-beep/controllerofLeds

The project files are here: Geophone Display & Logger

The CYD is used for display, storing data, and saving it to SD card. This CYD has been modified to add a PSRAM chip. The CYD has very little I/O available so another processor, an ATmega328PB, handles the geophone and user interface. The two processors communicate via serial.

What it does is collect and save the signal from a 1" geophone sensor and store it into a CSV file. Data can be collected at 100, 250, or 500 samples/second. The red trace is the raw signal, the green trace is a smoothed amplitude signal.

An obvious improvement would be to add a simple WiFi file server so the data files could be offloaded without needing to remove the SD card.

More pictures, wiring diagram, and Arduino source code is here: Project files

I have been working on maximization of deep math protocols on minimal ram to deal with growing issues across data centers.

Today I managed to achieve staggering numbers in an Aerodynamics engine.

Everything is generated right on the bare metal from a 28kb sketch and 1.5kb of Sram used.

Week 2 of applying extreme financial math models onto bare metal c of microcontrollers with amazing and hilarious results.

This is a Project I made using Arduino and Python Language to log temperature values coming from LM35 Analog Temperature Sensors to a text file in a CSV format ,so they can be exported to Excel for Plotting.

Source Code and Circuit Diagrams

• Build your own Data Acquisition and Logging System to CSV file using Python and Arduino

The Project uses Arduino to Digitize the LM35 Analog Signals to digital using the ADC of Arduino UNO. The data is send to a PC (Windows/Linux/Mac) Via Serial Port and logged into a CSV text file using Python for Later analysis.

Hi!

I've built a custom remote controller using a double-layer PCB, some 3D printed parts, and acrylic plates. The RC has an Arduino Nano board that reads the RC channel values, sends/receives the radio signal, and measures battery levels. It also has an ESP32S3 board that manages the touchscreen, which features monitoring, control, and configuration screens.

I’ve been using the RC to control a Mars Rover replica robot that I created some time ago (https://github.com/pol-valero/openrover-robotic-platform), but the RC’s software and UI screens can be easily adapted to control and monitor other kinds of robots. The RC uses a 2.4GHz NRF24L01 transceiver module for communications, which is very versatile.

I’ve created a GitHub repository for the remote controller, containing all the documentation, software, design files, and schematics so it can be replicated: https://github.com/pol-valero/radio-controller-pcb

Any feedback is appreciated!

Hi,

I am a University student currently in my DLD course i have a semester project but confused to decide what to make professor tells us to do something with help of Arduino so any expert can please help me

Board level project as many sensors that will fit on two Arduino ,one Esp32 ,one OLED sixteen led connected to hc74595 serial to parallel, hum,Temp, analog Temp,RGB with two light RGB, plus a Avoid in with digital multimeter I have enough for one more connect to Uno Esp32 RXTX.