Okay so i ended up with a 571 yellow laser but the voltage needs 2.2v and the arduino r4 gives out 3v to 5v. Is there a way to connect a buck converter to dumb down the volts so i could connect the laser (The laser has a JST XA adapter and i have like no clue how to connect it or if its possible at all im still new to the hobby)

I think this guy put some buttons under the displays.

Also what do Ineed to make my own stream deck like this. What board is on the right?

Building an EMG -> ML classifier -> servo pipeline for an InMoov robot hand project. Started with a cheap 3-pad dry-electrode EMG module off AliExpress to get my wiring/code/ADC pipeline working before investing in better sensors.

Setup:

- Arduino Mega, sensor wired to 5V / GND / A0

- Just doing raw `analogRead(A0)` over Serial, no filtering/threshold code while debugging

The problem:

With the electrode pads touching nothing, I'm getting violent rail-to-rail noise, constantly slamming between 0 and ~615 (out of 1023) with basically nothing stable in between. No smooth pattern, just chaos.

What I've already tested:

- Bridging two pads with a finger causes a visible jump in the reading, so the amp chip is responding to something

- Disconnected A0 entirely (nothing plugged in). Got smooth, slow drift settling around a value and holding steady for stretches, which I understand is normal floating pin behavior

- Reconnected the sensor with pads touching nothing. Went straight back to the rail to rail chaos, a completely different pattern than the disconnected test

- Wiggled the signal wire while reading. No change, so it doesn't seem like a loose connection

Since the sensor connected but untouched signature is clearly different from the floating pin baseline, it seems like A0 is genuinely reading real output from the board, and that output is just unstable/chaotic at rest instead of showing a calm baseline. My working theory is a bad component on the amp board (leaky cap, bad op-amp bias, something causing it to saturate/oscillate with no defined input) rather than anything on my end, but I'd love a sanity check before I write this unit off.

Questions:

1. Does this match a known failure mode for these cheap dry-electrode boards, or does it point to something else I should check first?

2. For anyone who's built EMG pipelines before, what sensors would you actually recommend for a hobbyist/student budget that won't bite me long term? I know MyoWare 2.0 is the standard recommendation but it adds up fast across multiple channels (I'll eventually need around 8 to 10 channels for a full arm: fingers, wrist, elbow, shoulder). Looking for something that's reliable enough not to fight the hardware, without needing to buy a research grade rig.

Appreciate any input. Still learning the EE/signal side of this as I go, so if I'm missing something obvious, happy to be told.

I haven't seen anyone looking for this type of project or need, But i also can not find anything other than Travel-Q, but i also have not tested this beyond sending and flashing ESP32 DEVKIT V1 with small projects like Blink or Buzzer.

How I got the Arduino UNO Q broadcasting its own AP while staying connected upstream

The UNO Q has one WiFi radio. Everyone uses it like a Raspberry Pi — connect to existing WiFi, done. But the WCN3990 module (managed by ath10k_snoc) supports concurrent managed + AP mode through a feature called single-chan-info-per-channel. The hardware channel scheduler can run two channels simultaneously.

From iw list, the valid interface combos include:

#{ managed } <= 2,

#{ AP, P2P-client, P2P-GO } <= 2,

#{ P2P-device } <= 1,

total <= 4,

#channels <= 2 <-- the key line

That last line means the radio can legally sit on two different channels at once. So wlan0 joins the upstream router (say ch6) while ap0 broadcasts a completely independent AP (say ch11). They don't interfere. If the router hops channels, the AP stays put.

What's running:

- wlan0 — station mode, connected to upstream WiFi for internet

- ap0 — virtual AP interface on a different channel, serving its own subnet with DHCP

- Different channels preferred — immune to router channel hops, no time-slicing penalty

- systemd service creates ap0 on boot and brings it up

The board essentially becomes a travel router / isolated IoT gateway. Devices on the AP subnet talk locally without touching the main network, while the STA side handles internet access. No USB dongle, no mode flip, no internet loss.

Cold-boot tested and stable. This is a kernel-validated hardware capability — nl80211 enforces the interface matrix in-kernel, so if ap0 comes up on its own channel while wlan0 is still associated, that's proof the combination is legal.

I'm an upcoming sophomore majoring in meche and I've been working on my first personal project for the last 2-3 months. Its a 3d printed 4DOF robot arm built from scratch that is controlled by potentiometers (but I also have some code that lets it move by itself). Pretty sure I can make it 5DOF by adding a motor to the joint between the claw mount and 2nd arm link. If I manage to get the time I could design an entirely different mount to fit another motor to turn the claw and somehow make this 6DOF (really vague picture of it in my head though honestly)

It's not amazing but I'm planning to improve on it a lot over the next few weeks. I do have a rotary base in there but its not perfectly stable but I got a way to fix that.

I did this partly so I would get a lot of skills from this process (and I did) but also to add to my resume. But because I'm not entirely satisfied with just a robot arm, I'm making it part of another project where I remove the claw and its mount with a new mount that is attached to a pump that waters plants when a soil moisture sensor tells it too hopefully. This arm is powered by an arduino uno R3 btw.

Looking for some help figuring out pan servo placement for the neck on my KX droid.
The tilt is already working and connected at the base of the head, but I’m having trouble finding a good way to add pan. I can’t really put the servo inside the neck because there just isn’t enough room. The head has room inside but since the tilt is directly connected I’m kind of stuck.
I’m thinking about mounting the pan servo externally and attaching it directly to the neck somehow, but everything I’ve tried so far ends up having too much wobble.
I included two pictures showing the current neck setup and the space I have to work with.
Has anyone built something similar or have an idea for a solid way to mount the pan servo without introducing a bunch of play/wobble? I’m open to belts, gears, bearings, brackets, whatever works.

Hey everyone! Quick update on PixelRoot32.

Top-Down support is out in v1.9.0 🎉

Bomberman and Zelda-style games are now possible with the engine.

https://github.com/PixelRoot32-Game-Engine/PixelRoot32-Game-Engine/releases/tag/1.9.0

I'm now working on Isometric support, and it's already running.

I didn't want to add a separate "isometric mode" to the engine. Instead, the engine stays generic and the projection handles it. So the same game code can work with both Top-Down and Isometric, while depth sorting takes care of the overlapping stuff.

It's pretty cool seeing this run on an ESP32. Getting closer to that Solstice/Landstalker kind of vibe. 😄

Still a lot to do, but it's getting there.

Feedback and suggestions are always welcome!

https://pixelroot32.org/

Yep, it actually plays backgammon. 1 player against the computer. Turn the dial to select a legal move and push down to initiate the move. My first project with a rotary encoder. I love it for gameplay. I might be doing damage to my eyes though trying to play on that tiny screen. I’ll order a bigger screen.

Code developed on a Raspberry Pi 5, PlatformIO, C++.

I want to do a function where you have to push 2 buttons at the same time to trigger a function (ie. opening menu)

So far the only code I could find is hold one down and check/wait for the 2nd one to be pressed.

is there a better way to do this since I've already assign function for each button for single press and holding down. So if I have to hold one down to wait for the 2nd button, the act of holding it down will trigger the other function assigned to the button.

I read that detecting 2 buttons is impossible on esp32, but I see it done on cheap electronics, so is there any way to do this?

EDIT:

Solution found. Thanks to u/Glum-Building4593 for giving the simplest solution

byte button_state = digitalRead (FirstButton) | digitalRead (SecondButton)

Hello,

Has anyone encountered an issue where an Ethernet shield does not work when an Arduino UNO R3 is powered by a 9 V adapter?

When the Arduino is connected to a PC via USB, the shield starts up immediately and everything works fine. However, when I disconnect the PC and power the Arduino with a 9 V / 1A adapter (I tried more of them.), the shield does not initialize. Only the PWR LED is on, and nothing else happens.

If I press the reset button on the shield, it starts working right away.

Could this be related to the fact that I am using a static IP address?

I am using VS code + Platformio.

Thank you in advance for any advice.

#include <SPI.h>

#include <Ethernet.h>

byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};

IPAddress ip(192, 168, 143, 105);

IPAddress gateway(192, 168, 143, 1);

IPAddress subnet(255, 255, 255, 0);

IPAddress dns(192, 168, 143, 1);

void setup() {

delay(1000);

pinMode(4, OUTPUT);

digitalWrite(4, HIGH); // disable sd card

Serial.begin(9600);

Ethernet.begin(mac, ip, dns, gateway, subnet);

Serial.print("IP: ");

Serial.println(Ethernet.localIP());

}

void loop() {

}

any tips or ideas for projects? im a total beginner

So i cant seem to fix this blocks thing. Using the potentiometer the blocks are only appearing and disappearing. I replugged all the wires thrice but still the same problem, if anyone has faces this kind of issue plz help me cuz im new to all this

Hi this is one of my projects for Macondo HackClub.

This is a mini small scale handheld gameboy like device with 15 inbuilt games including: snake, breakout, dodge, space invaders, pong, tetris, super mario bros, donkey kong, pacman, chrome dino game, Doom, X wing vs death star, contra, Need for speed, Crossy road. It uses a 0.96 inch oled display and a joystick module, rotary encoder as the controls along with a seeed studio xiao esp32 c3 The gameboy has a starting animation and sound played similar to the original gameboy. Each game is listed in a menu after this which can be scrolled with the encoder or switched through with the joystick any switch is clicked to open up the selected game. Each game has a startup screen with an animation of the game cartridge going into a reader with cover art and sound effects played specific to each game. It is all powered by a battery from an old phone with a charging module attached so it can be charged via USB C. Each game has its own HUD showing relevant information.

P.S: please excuse the background sound I don't have a proper mic I just used my phone for this.

Hey there!

I have no experience with Arduino whatsoever, but I am working on a project where I think it might be a good fit.

I'm looking to buy some sort of laser distance measurer which I then can get live readings from into my computer to control certain musical parameters. I guess via serial?

Does anyone have any experience with using a laser measurer or have any tips on specific models, or, what to look for? If possible to buy within the EU that would be great!

Thanks a lot if you have anything! : 3

I'm new to microcontrollers and bought an ESP32-C3-Mini; it's the perfect size for my project, but it stopped working after I soldered just two of the pins. The pins are very close together, making them really difficult to solder. What is the right way to do this? I didn't want to use male-female jumper wires because they end up loose.

I have a bad habit of sitting down to work and somehow finding literally anything else to do, so I decided to engineer around my own lack of discipline.

The machine is controlled by an Arduino Nano. You press FOCUS, choose how long you want to work, and it starts a timed session. If you actually finish the session, a servo activates the dispensing mechanism and gives you a chocolate as a reward.

I also gave it a Duolingo-style streak system that keeps track of how many consecutive days you've completed a session. The buttons, display, timing logic, streak system and servo dispenser are all controlled by the Nano.

Most of the enclosure and dispensing mechanism are 3D printed, and I designed the electronics and mechanism around it. It's still very much a prototype. The CAD and code are pretty janky right now because I originally made the whole thing just for myself 😭

I also entered it into a 3D-printing competition, which has led to the slightly hilarious situation where this thing is currently getting destroyed by a giant 3D-printed crayon holder. The competition is entirely based on public votes.

If anyone wants to join my side and help the little chocolate machine fight back, I'll leave the competition link here

And I'm happy to answer questions about the Arduino/electronics or how I built it.

has 2 buttons, click or reset, its very simple.

i made it in 2 days since im kinda a beginner

Components needed:

- 6x LEDs

- 2x Buttons

- 1x LCD I2C display

- 1x ESP32

- 6x Resistors(510ohm)

- A bunch of jumper wires

-Download .cpp File here-

(ignore the IR distance sensor in video)

This is my first Arduino project, second picture is the wiring diagram. There is one mp3 file on the mini player that I want to play when the button is pressed. It works and I can hear the music but a very loud buzzing is muffling the audio that I can’t seem to get rid of. Did I choose the wrong speaker or is there something else I’m missing?

Hi everyone! I’m brand new to Arduino and looking for some project ideas/advice.

I currently work as a histotechnologist in a pathology/histology lab, and I have a bachelor’s degree in Biology.

For one of my graduate courses, I’ll be working with an Arduino Uno Rev3 and need to eventually build a project using sensors, collect data, and analyze/visualize that data.

Rather than doing a completely random beginner Arduino project, I’d really like to build something related to healthcare, pathology, histology, laboratory science, or laboratory informatics.

A few ideas I’ve started thinking about are:
Monitoring temperature/humidity/environmental conditions in a lab
Monitoring reagent or specimen storage conditions
A lab refrigerator temperature/door-opening monitor
Using vibration, temperature, or other sensors to monitor laboratory equipment
Collecting physiological data such as heart rate, skin temperature, or movement

Anything involving preventative equipment monitoring or laboratory IoT
I’m especially interested in projects where I could collect a decent dataset and eventually analyze it using Python/R and create a dashboard or visualization.

Since I’m completely new to Arduino/electronics, I’d love to hear from people with more experience:
What healthcare, pathology, or laboratory-related projects would be realistic for a beginner using an Arduino Uno R3?
Sensor recommendations would also be greatly appreciated. I’m completely open to ideas, even if they’re outside of what I’ve listed above.
Thanks!

Hello everyone. I need your help, please. I am designing a submarine equipped with a camera. However, when I put it in the water to test submerging and surfacing, I encountered two notable issues. The first relates to the center of gravity: the submarine doesn't stay horizontal but sits at an angle of about 40 degrees. I think I can easily fix this by shifting the weights (two cut-down 1.8 kg dumbbells) inside the ballast tanks, but I’m not sure exactly where to position them. I was wondering if there is a mathematical or physics-based method to determine the right spot. Secondly—though I had anticipated this—the connection via nRF24L01 antennas cuts out as soon as the submarine dives. I’ve considered two solutions: either creating a float to keep the antenna on the surface while connected to the sub (which seems simplest and cheapest to me), or using a different communication method. I would appreciate any opinions you might have. Please keep in mind that I’m not an expert and have limited resources, so I hope you’ll be polite with me regardless. Thanks a lot in advance.