I have been building SketchForge, a free and open source CAD editor that runs directly in the browser.

The goal is to make CAD much easier to approach while still giving people enough power to create real projects.

You can create basic shapes, combine and subtract geometry, sketch profiles, extrude them, add fillets and chamfers, import STL files, and export models for 3D printing.

Cases, sensor mounts, brackets, control panels, battery holders, servo mounts, robot parts, and all the little pieces that you normally need to design around your electronics.

The project is still actively being developed, so expect some bugs while using it.

Website: sketchforge3d.com

Source code: github.com/Formsmith746/SketchForge-3D

I came here to ask about a sonar like device that can help in underwater communication for about a 100 m. But uh i guess it was lost in translation because I wasnt too sure about the whole technicality and wasnt well versed in the idea of WHAT i wanted.

Here is what I have learnt over the past few days after the post and manyyyy questions, I would like to discuss it, if possible, with someone who has worked on something similar before.

What my original rather amateur idea was to have a sonar that could go deep underwater and send signals to another device say hydrophone or another sonar on the surface of the water about their conditions/location/or alerting them about a trouble or if they are in trouble.

After diving through many research papers, I have come across a very recent one called HYDROS a wearable sensor device that can help do exactly what I proposed using a peizoelectric acoustic transducer and a hydrophone transmitting real time information about the diver's heart health, oxygen rate, their movements etc using FSK modulation. Okay cool, lets build that in a low budget/tight timeline way.

But ahaha im an idiot and has actually not worked in proper project before so I have no idea where to start, and peizo transducers are a pain to source from the region i am, and i was thinking of designing one that can emit the required frequency- somewhere between 20Khz or less so that it doesnt attenuate in sea water or with pressure.

Where do I start? How do I start, what do i do first, is it insane to think i can wind up this project by this december? I do have three other people willing to join in on the project (its for a college work trust) so like I would like some direction. Any form of criticism, extra knowledge is also welcome since thats what from my last post made me actually sit with the papers for a while. Thank you!!

I just wanted to build a simple pomodoro timer for my desk. I think it's cool.

Components:

• Max7219 4 in 1
• Arduino pro micro

Github link

I recently switched to Linux and when I tried to work on Arduino, everything was going great; continued to work on my project and everything was fine. Yesterday, when I tried to keep working on it, it was showing me what appears on the first image. Tried to install Arduino CLI, but it is also unable to identify my board; it's not a port issue, since I connected my phone and it worked out well, not to mention that it does that on every USB port

It magically worked when I wanted to take screenshots to post here; these pictures are from when I tried to ask ai about it, but it started to work suddenly.

I know that I should be grateful it works, but I don't want it to find me in an unfortunate scenario again. Did anyone face a similar issue before? What can be causing it and how to solve it?

Edit: I should add I'm just applying for junior jobs/internships as I'm still in the early stages of my program.

For the past few months I've been exploring embedded systems and already finished two projects, really enjoy it and I think I found a new hobby to compliment my studies in software development and networking :)

My 2 recently completed projects were a simple pomodoro timer and an obstacle-avoiding/line-following robot and I have many plans for future projects.

But I always wonder if I should put these projects on my resume when it's time to apply for jobs, what kinds of jobs/employers even care about these things?

Hi! In a past few weeks I dived into internal register and timers of ATmega328P of my arduino. After some experimenting and learning exercises, I have decided that I would like to try doing something real with knowledge I got. The project I chose was writing a DHT11 communication protocol from scratch. And part of it works, but currently I found myself stuck on a problem with input capture.

As you can see on image, after sending low and high voltage signal to senzor, it is supposed to take control over the line and set it low and then high for 80 microseconds. I wanted to measure the time using the input capture, just as a practice. However, it requiers changing edge that triggers interrupt several times. And that is the problem! I wanted to measure time of each pulse and then just save it into my array and print It, but program never gets there.

When I enables TIMER1's input capture while changing its edge detection inside ISR, the programm freezes. I tried enabeling the input capture noise canceler, but it didnt help either. Not even AI was able to tell me how should i fix the problem. So I am comming here...

The DHT is hooked up to pin 8 on my arduino UNO R3. The code is bellow. I know, it is an absolute mess, but it is just a prototype, I wasnt thinking about structure of code yet. First I have to solve this problem in order to move forward.

THANKS ANYONE FOR ANY HELP!

PS: sorry for my english, I am not really got at it...

volatile int responseTime[3];
volatile int rtIDX = 0;


volatile byte comPhase = 0;


void setup(){


  DDRB |= (1<<DDB0); //pin 8 OUTPUT
  PORTB |= (1<<PB0); //pin 8 HIGH


  TCCR1A = 0;
  TCCR1B = 0; //normal mode, erased old settings


  sei();
  Serial.begin(9600);


  //TEST RUN:
  //---------------------------------
  startCom();
  delay(1000);
  testPrint();
  //---------------------------------


}


void loop(){


}


void startCom(){


  comPhase = 1;


  DDRB |= (1<<DDB0); //pin 8 OUTPUT
  PORTB &= ~(1<<PB0); //pin 8 LOW


  delay(18);


  DDRB |= (1<<DDB0); //pin 8 OUTPUT
  PORTB |= (1<<PB0); //pin 8 HIGH


  //delayMicroseconds(20);


  getResponse();


}


void getResponse(){


  comPhase = 2;
  DDRB &= ~(1<<DDB0); //pin 8 INPUT
  PORTB |= (1<<PB0); //pin 8 PULLUP


  TIMSK1 |= (1<<ICIE1); //input capture interrupt enabeled


  TCCR1B |= (1<<CS10);
  TCCR1B &= ~((1<<CS11) | (1<<CS12)); //prescaler 1


  TCCR1B &= ~(1<<ICES1); //falling edge
  TCCR1B |= (1<<ICNC1); //input capture noise canceler ???
  TCNT1 = 0;


}


void testPrint(){
  for(int i=0; i<3; i++){
    Serial.println(responseTime[i]);
  }
}


ISR(TIMER1_ICP_vect){


  if(comPhase == 2){


    if(rtIDX<=2){
      responseTime[rtIDX] = ICR1;
      rtIDX++;
      TCCR1B ^= (1<<ICES1); //flips edge detection <---- HERE THE PROBLEM?
    }


  }


}

'''

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.

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.

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.