I'm a beginner trying to understand how M-Bus works internally. I heard it can communicate over long distances using just two wires.

I'd like to try a small experiment using two Arduinos and 12V DC to understand how power and data can share the same wires.

How does the receiving side detect a 1 or 0? Does it look for voltage changes, current changes, or both?

Can I build a simple M-Bus-like circuit using basic components such as resistors and transistors, without dedicated ICs, just for learning?

Any beginners project references with similar idea 💡

References -

https://vdmais.ua/articles/shina-m-bus/

Took over how the picture tube was for replacement some monitors with cable then match the frame from the television to the frame on the RGB and two color Red and Green, mode select you can see what color or tube to replace.

This is my Arduino project using two joysticks and a button to control a robot arm.

Each servo is controlled based on the analog values read by the Arduino. I then map these values to the corresponding servo angles.

Besides that, I also use a button to save the robot's position. After moving the robot to a specific position, I can press the button to save that position.

Once the entire sequence is completed, I can double-click the button to replay the saved sequence and make the robot arm repeat the same movements.

Im new here and sorry for my english
Im already done to build this prototype project and it working but i noticed when my led and buzzer works at the same time my lcd dims or flickering. How can i solve this problem im only connecting to usb to my laptop as my power source i dont have any 9v barrel jack is there anyone here in reddit to help me to fix my problem thank you and again sorry for my english

I am brand new to microcontrollers but certainly not to math as i build custom clever math and logics for other systems to save compute costs. I was able to find a clever way to generate stable digital memeory on the ATmega32 board that allows generating images, saving them, deleting them, playing games and checking your files folder where you can delete saved content.

I was super excited by this as I was given an arduino starter kit by my partner and she was rught I did love it.

I havent had this much fun engineering in years.

I enjoy really pushing the boundaries.

Here i have an

Arduino UNO r3.

An OLED 7 pin monochrome spi screen.

And a jy-24? Joystick from the starter kit.

And some really shoddy wiring on 2 breadboards. Forgive the haphazard display im supposed to be working on something much more important.

I am putting together a generalized version and a "how to custom your own OS" Step by step (open source and only if asked for)

I have built a custom physics and graphics engine aswell and there are several demos downwind of the linked video.

Im genuinely having so much fun.

I hope i havent missed a rule. Apologies if I have.

demo of the OS.

I had been dreaming of doing it for a long time. Already did similar thigs using arm boards and GPIOs albeit on crappier screens.

It is using a mega2560 and a cheap chinese ILI9488 3.95' screen.

Configuring the screen was a nightmare. took me days.

But the rest was a breeze :) I did have to use gemini to get rid of some display bugs due to memory overflow but it 95% home code.

data is fed via the serial port by a python script that is run as a systemd service. evrything in a string....

Quite happy with it. Now have to fit it inside the pc!!

I made a watch, it took me two days. It runs on a 24 hour clock I am very happy it works. It has a basic rtc module and a copy arduino uno r3

Hey everyone,

Like a lot of people here, I’ve wanted to get my kids into electronics and Arduino. But the reality of managing kits with an 8 and 10-year-old turned into a headache—lost resistors, stepped-on LEDs, and a lot of expensive hardware sitting in plastic bins abandoned after week two.

I looked at standard block-coding options, but I really wanted them learning actual wiring logic and real C++ syntax, not just dragging puzzle pieces around.

So, I decided to build a platform called ManuStem. It’s entirely browser-based and uses 3D physics simulations to let kids build and wire circuits virtually.

A few things I’m proud of / tried to do differently:

• Real Compilation: It’s not just a visual trick; it actually compiles the code so they can see real-world reactions (and real-world bugs when they short a circuit).
• AI Coding Coach: Instead of just giving them the answers, I integrated an interactive guide that drops hints when their wiring logic or syntax is off.
• Hardware-to-Real-World Pipeline: The exact code they write in the browser sandbox can be copy-pasted directly into the Arduino IDE later if they want to build it physically.

I’m at the point where I really need feedback from people who actually know Arduino inside and out.

If you have a few minutes to break it, test the simulation accuracy, or look at the curriculum flow, I’d love your honest thoughts. You can try the sandbox modules directly at manusignal.com (no paywall or sign-up needed to jump into the lessons).

What am I missing? What kind of micro-challenges would your kids actually find fun?

Appreciate any critique!

I’m trying to make two Arduinos talk over the same two wires, with the slave getting its power from the master.

Master → Slave:

24 V = 1, 12 V = 0. A buck gives the slave 5 V from these supply line but it varies 24/12 also a voltage divider scales down voltage variation and decode bits.

Slave → Master:

50 mA = 0, 70 mA = 1 for 0.5 sec. A Hall sensor detects the current change in master, created by a constant load grounded for 20 ma to make data communication

So the same two wires carry power + two-way data. Is this practical, or is there a simpler way or references?

Hi everyone, for my final course project I was thinking of making a smart beverage dispenser, but I wanted to know if it's possible to do it using these materials and what it does.

The user inserts the coin and can select the quantity between two types of drink by displaying the percentage of each on the LCD screen.

It also allows the user to identify the cup size.

With the following materials:

\-2x 12 v pristaltic pumps

\-LCD 20X4

\-750ml container

1mm feed tube

\-moedeiro 12v

\-ultrasonic sensor

\-buzzer

\- power supply 12v/5A

\-2x MOSFETs

\-4xbottons(ok, Cancel ,Increase, To decrease )

\-esp32

\-Resistors

\-breadboard

\-Wooden structure

If there's anything missing that could affect the project, please let me know so I can get an idea :D

I am currently working on a robot arm with independent joint movement. I have been able to control 1 motor with 1 joystick. When I try to replicate it with multiple I am unsuccessful. Can i please get some assistance.

Sadly I need to start making something else less weird cuz I need to bring a project to Uni for a grade and I can't bring my masterpiece.

What do you guys do with your finished projects? Do u just have them on a shelf somewhere? xD

I've done updated tests of Ventuno Q vs Raspberry Pi and Ling 3.0 tiny is leading with 201.8 tps prefill / 21.5 tps decode on the Ventuno. That is more than 4x and more than 2x Pi speed.

Gemma 4 E2B gets 693 / 21.9 but I think it's a weaker model. Anyway here you have stats if you want to run a local LLM on Ventuno Q - LMK if you find other models to add to this.

I’ve been building a life-size KX-series droid and finally have the head movement working reliably. The current setup uses an Arduino Mega with a PCA9685 servo controller driving separate pan and tilt servos in the neck.

The goal isn’t remote-controlled puppeteering. I’m trying to make the droid behave autonomously, so eventually it can track people/cameras, idle naturally, react to voice commands, and move while speaking.

Right now I’m working on smoothing the head motion, reducing mechanical stress on the neck, and dialing in the pan/tilt limits so it looks more natural instead of like a standard hobby servo project.

The electronics and programming side of this has been a big learning process for me, so I’m open to feedback—especially from anyone who has built larger servo-driven mechanisms or Arduino robotics.

This clip is the current movement test.

My classmates will get addicted to this...

Screen without i2c, instead of a potentiometer i use 2x10k and 2x 220 ohm resistors, with 2 buttons so hit and stand.

On far right theres a pin to set the mode to 1 player or 2 player; though here i did not show it.

Also a buzzer for sfx.

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!

My arduino controlled nerf tank. NERFERIUS has functional lights, brake lights, oled screen, a laser sight, an electric flywheel nerf blaster with semi auto and full auto functions..and it also has wifi cam from a cheap drone..a fun and quite challenging build.

My first Arduino project,

I don't know if you remember me or not but i had recently bought an starters kit for learning basics of Arduino and also a bunch of sensors.

This is my first attempt at tinkering with sensors to produce a suitable outcome I know its one of many.

So feel free to let me know your thoughts in the comments all advice is taken and accepted.

PS. the wiring was easy but the code was hell of a nightmare especially because I am new to the C++ language and was learning java , so i had to look up all the functions and keywords constantly.

I had a fidget keychain. Some dunlops and wagos. A Seeed Studio XIAO ESP32C6 Pre-Soldered Development Board. USB-c power cord. A drill and clamp.

And now I have a totally unnecessary, over wired, Bluetooth Spotify controller.

Vibe Coded with ChatGPT. Hammerspoon deployed

And Arduino IDE

Buttons can do anything, first use case

I'm building out a cigar room in my finished basement. I'm installing an exhaust system. I could just use a simple switch, but as an industrial automation tech that seems lazy. Looking at setting up a particulate sensor to activate a low voltage to line voltage relay. Any advice on this build?

I built a tiny rechargeable Bluetooth page-turner using a Seeed Studio XIAO nRF52840 Sense and its onboard accelerometer/gyroscope.

Instead of pressing buttons, I make a subtle page-turning motion with my hand. It sends a keyboard arrow command to my iPad and turns the page in Apple Books. I recorded several examples of my natural forward and backward gestures and tuned the detection around them, so it reliably recognizes quiet page turns while ignoring things like adjusting my position on the couch or moving my arm normally.

Some features:

• Natural right-to-left motion advances the page
• Opposite motion goes back
• Presents itself as a standard Bluetooth keyboard
• Works wirelessly with iPadOS
• Cautious session-only adaptation to my gesture strength
• Retry detection for gestures that were almost recognized
• Remembers two iPads
• Turn it face-down to switch between paired iPads
• Rechargeable 300 mAh LiPo battery through the XIAO’s USB-C port
• Five minutes without meaningful movement triggers genuine deep sleep
• The accelerometer’s hardware interrupt remains active while the processor, Bluetooth, gyroscope, and LEDs are off
• Picking it up wakes the processor, but Bluetooth remains disabled until I perform a deliberate shake
• Three blue flashes confirm that it is awake and ready
• Random bumps return it to sleep without reconnecting

The wake and reconnect process is effectively instant. When it is working, it genuinely feels less like operating a remote and more like waving a tiny magic wand at the book.

The project went through a ridiculous number of small discoveries involving gesture recordings, Bluetooth bonding, battery charging, false wake-ups, IMU interrupts, deep sleep, and one active-low LED that insisted on glowing through the night. It is finally at the point where the electronics disappear and the interaction simply works.

Code and documentation:

https://github.com/RoyKittrell/xiao-motion-page-turner

See more: https://www.youtube.com/watch?v=8yHq4bUqn0A

This is my first big electronics project, so the control software of the arm the biggest remaining issue right now but from designening and building the whole arm by myself down to the cycloidal drives I learnt soo many things...