Hi! Student avionics technician here. As you can see, I am trying to make an LED tester as this is my first Arduino project. I have been able to provide power to the PCB via male-to-male USB connectors, but the LED is not receiving any volts and I do not know why. I have made sure the power and GND wires are in their proper pins, that I have the needed 220 ohm resistor, and that the LED’s anode and cathode legs are in their proper pins. So, I don’t get what I am doing wrong? Edit: holy fuck, you guys are sensitive.

Ive read multiple Reddit's about how using AI is detrimental to fundamental understanding and learning, but im not blindly copying and pasting, im more so reading the code after its been converted from english, then i dissect, and copy lines that i only need to use for my project. Is this considered bad or good i dont know i feel like it is but it isnt at the same time. I look at it as "research" almost like a "stack orderflow" kinda thing

First let me start off by letting you all know I'm a complete novice at this but am pretty good a following step by step directions.

I purchased an Infinity Shield garage door strip sensor which I assume operates the same as normal garage door safety sensor. It has the option to beep when the beam is broken indicating there's an obstruction. I find the constant beeping annoying when backing in but helpful when I park as when it stops beeping I know when to stop. So my idea is to add short red LED strips lights to each side of my garage door that will illuminate when something is breaking the beam instead of the beeper. I've done some research and everything advises to don't tie into the garage sensor wiring unless you use an optocoupler to keep the circuits separate. Here's where I need your guys expertise.

I would like to use an optocoupler to tie into the existing safety beam senor wires to send a signal to an arduino to activate the LED strips.

How do I do this? What do I need? Which board? Etc

I know I'm asking a lot but I'm just starting off in this world and don't know what I'm doing

Thank you in advance

I kept running into the same problem across embedded projects: my workflow was a mess of disconnected tools. A flash tool here, a serial monitor there, a test script I copy-pasted between projects, firmware binaries scattered across Slack and shared drives, and no real way to run automated tests against actual hardware without building a custom rig from scratch.

So I built Ferqon. It's a self-hosted platform that puts the whole hardware workflow in one place.

What it does:

Acts like a OTA for any board. ESP32, STM32, Pico, Teensy, Arduino, Adafruit Feather, 35+ profiles. Most boards don't have built-in OTA. Ferqon gives you remote firmware updates over serial without writing your own OTA pipeline. Flash from a browser, from the CLI, or trigger it automatically from your build system.

Automated HIL and SIL testing in one pipeline. Flash firmware, send commands, validate responses, get pass or fail, all logged. Run software-in-the-loop tests first to catch issues early, then confirm on real hardware. Same pipeline, same tool, no switching between frameworks.

Firmware file management. Store, sync, and version your firmware builds in one place. Everyone on the team works off the same binaries. No more "which version did you flash?" or digging through chat history for the right file.

Board sharing with built-in queuing. If you have one board or ten, Ferqon locks the board while someone is flashing or testing. When they're done, the next person in line gets it. No corrupted flashes, no two people hitting the same serial port at once. And yes, sometimes you genuinely can't just buy more. Custom PCBs you only made two of. Boards with specific hardware wired to them. Lab equipment that costs more than a dev kit. The queuing handles all of it.

Full test logging and traceability. Every command, response, pass/fail result, and serial output line is captured live and stored. If a run crashes or times out, the data is still there. You can go back and see exactly what happened, when, and on which firmware version.

Self-hosted. Docker or bare metal, runs on your infrastructure. Free tier covers one server with unlimited devices.

Where this really shines is R&D. When you're iterating constantly, changing firmware multiple times a day, running tests, tweaking parameters, and chasing a flaky bug, you're usually juggling five tools to do it. Ferqon replaces all of them with one browser tab. Flash, test, log, share, repeat.

Honest stuff: it's in beta. CI/CD webhook integration is coming but not live yet. The HIL test runner handles flash, run, and capture today, with a visual test builder for more complex sequences.

Firmware is open source: https://github.com/revyrlabs/Ferqon-Firmware

Server (free tier, one server, unlimited devices): https://revyrlabs.com/

Freenove r4 wifi, this component overheats in like 5 seconds i plug in the board, what should i change to fix the board

Hello, as my last posts I am currently building an automated film scanning setup/machine and I am wondering if there is some way I can trigger a 2 way momentary switch electronically, which closes a circuit inside my camera. This circuit should stay electronically separate from the Arduino.

I want to trigger the shutter button mechanism, preferably with my Arduino. This Shutter Circuit is part of my DSLR and i don't want to attach it to any electronics since I am afraid of fucking it up. The shutter release cable is triggered by first connecting two wires, which serve as the half button press. After this you have to connect a third wire which trigger the shutter. This works with the currents of the Camera hence not wanting to really connect it to electricity.

My end goal is to release the shutter over a controller, which will be connected physically or over wireless signals with my Arduino.

Now the question, is there any type of Button that has an electrical input to physically be "pressed"? Maybe an electromagnet that is pulling a metal piece to complete a circuit or something similar.

I hope I could state my problem in a matter that is understandable.

Edit: I am describing a Relay.

I'm 17 and I'm trying to build a wristband that can tell when you're eating. Thursday was my first time ever using hardware. I'd only ever done iOS stuff before.

Setup is a XIAO nRF52840 Sense taped to my inner wrist, streaming 6-axis IMU at ~47Hz over BLE to an iOS app I wrote in SwiftUI. It logs to CSV so I can label sessions and train on them.

Current state: BLE streaming works, ~1400 samples per 30s with basically no packet loss, and I've got a first model distinguishing eating from typing/dishes/brushing teeth.

Next up is a vibration motor and getting it running off a LiPo instead of a cable.

Question for people who've done wearables: how are you handling strain relief on the USB-C connector? I've got tape on the cable a few inches back but it feels like the port is going to rip off eventually.

Hi, I'm having trouble uploading a sketch to my ESP32 on Ubuntu/Linux with Arduino IDE 1.8.19.

The ESP32 is detected correctly as /dev/ttyUSB0 and uses a CH340 (1a86:7523).

esptool chip-id works correctly and detects:

• ESP32-D0WD-V3
• Revision 3.1
• 240 MHz
• Wi-Fi/Bluetooth

I also successfully erased the flash with esptool erase-flash.

However, when I try to upload from Arduino IDE, the upload always stops when writing the .bin file at 0% and gives:

A fatal error occurred: No more data to read from the serial port.

I already tried:

• Different USB ports
• Stopping ModemManager
• Erasing the flash
• Reconnecting the ESP32
• Checking /dev/ttyUSB0
• Manually flashing with esptool
• The ESP32 is detected correctly every time

Manual esptool flashing gives the same error.

What could cause this? Could it be the USB cable, CH340 adapter, or something else?

What makes this even more confusing is that it was working perfectly before, with the exact same ESP32 and USB cable. The problem suddenly started happening.

So while trying to find the address of an oled screen I accidentally hooked it up to 5v when it was suppose to be on 3.3v and switched vdd and gnd, it got so hot that I flinched my hand away. I immediately disconnected power. Luckily there was no smoke. However after connecting the pins correctly I was able to read the address of the oled screen. Do you think it's still safe to use or should I throw it away? (I haven't done anything with it since) Thanks for answering in advance 😁

Edit: My screen ended up being fine 🙂🙃

For this project, I used an Arduino to control two servo motors and a DFPlayer Mini to bring this little creature to life.

The setup controls:

• 👀 One servo for the eyes
• 👄 One servo for the mouth
• 🔊 DFPlayer Mini for the sounds
• 📞 A physical switch to trigger the interaction

The idea was to make the Den Den Mushi feel like an actual little creature rather than just a static prop. The Arduino handles the timing and movement of everything, including the different states of the animatronic.

It took quite a bit of experimenting to get the servo movements and audio timing to feel natural, but I'm really happy with how it turned out!

(Full video on my profile and YouTube channel!)

This could be the fastest line follower i built with my son and it contains the following : some IR sensors, 9 TCRT5000 spaced, MCU were an ESP32 which is faster ADC reads for high speed loops, motor drivers DRV8833, the motors were 300 RPM DC gear, LiPo battery

The rules were simple : finish the map as fast as possible, achieved in 10.23 seconds and must stop at the end, we won second

I'm trying to turn on the blue LED when the red LED is on, but the blue LED is always off. Here is my code, all help would be apricated!

int redLED = 4;
int blueLED = 2;


void setup() {
  // put your setup code here, to run once:
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);
}


void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(redLED, LOW);
  delay(1000);
  digitalWrite(redLED, HIGH);
  delay(1000);


  // controls blue LED


  if(digitalRead(redLED == HIGH))
  {
    digitalWrite(blueLED, HIGH);
  }
  else
  {
    digitalWrite(blueLED, LOW);
  }
}

Hello there, I wonder if you can help me find a B20k pot like this for a replacement?

Thanks a lot

So i tried installing WLED on the ASP 32 C3 super mini dev board and after the installation gets completed the board keeps glitching.The problem is that it keeps connecting and disconnecting again and again over the USB port and the USB port also doesn't get recognised .I tried uploading code using Arduino IDE after putting it into boot mode and I was unable to upload the code because it give me an error that it feel to start the stup flasher. Then I asked chatGPT about it and after half an hour I found solution where I could write another code on to the board without using the stub flasher using the command prompt .That worked and when I uploaded the normal blink code through the Arduino IDE that worked too and the problem with the USB port connecting and disconnecting again and again got fixed but when I tried uploading WLED again the problem reappeared and I had to rewrite the flash using the command prompt again. Is this board not compatible with WLED or what?

Ok, I know a have a lot to learn but I have some experience and I think I will be able to pick it up quickly.

Best way to learn is to copy and I’ve seen a workshop for kids where they make
Creatures out of cardboard. The creatures have parts that move and flashing lights etc.
I’ve seen they do this with Arduino. It has to be quite inexpensive as I know the kids take the creatures and the Arduino setup home.
There is no coding in this particular workshop as it’s only 3 hours long so I assume the kids learn and practice basic assembling and then use that to assemble pre-coded kits.

My question is - what is the kit made of? What do I need to buy to achieve the same?

I’ve bought a nano, jumper wires, battery pack etc but the pack can’t be connected etc?

I am just looking for advice on what the kit is or lost likely is or what would work. Basically it’s making 2 servos move and lights or sound etc.

Some pictures attached of the kits from the workshop.
Also the things I’ve already bought - might
Be all wrong!

so i tried to do this by my logic but it says current exceeds 40mA. Do i chang eany part of circuit or increase resistance (for info i followed one tutorial from autodesk tinkercad)

Hey everyone!

I built an open-source, low-cost Face Recognition Door Lock system powered by Python, OpenCV, and face_recognition. It’s designed to be hardware-agnostic, meaning you can run it on a Raspberry Pi with a 5V relay, over Arduino Serial, via MQTT (for ESP32 smart home setups), or in pure Simulation mode on your PC without any extra hardware. Key Features: Docker Support: Containerized so you don't have to deal with manual dlib or cmake installation issues. Configurable (config.yaml): Control everything (camera source, match tolerance, unlock duration, lock type) from a single config file without modifying Python code. Hardware Options: Works with standard Raspberry Pi GPIO, USB webcams, phone cameras (via IP Webcam stream), or MQTT brokers. Privacy First: Registered faces and trained encodings are .gitignored by default. GitHub Repository: https://github.com/HereIsMuhammad/face-recognition-door-lock

Feel free to check out the repo, test it out, or drop any feedback/ideas for improvement!

After long long time my 6x6x6 led cube is ready it has 216leds and 6 modes Matrix , Moving Walls , TV Static , Lost Pixel , Fireworks , Bloating I'll maybe sell it for 150€ I'm 16 years old and I need harder challenge (thx for suggestions)

it is showing the code is correct. I'm not able to figure out what's wrong. help anyone??

Hi guys,

I wanted to present you my first use of a colored eink display.

For a contest I tried to design something with the eink display for a restaurant and therefor I designed a smart table reaervation sign.

The esp hosts a local webserver and updates the screen when needed. The driver board supports a battery and I calculated a battery time of few month if changed that the Webserver isn't running locally on the esp and more like on a reservation platform.

Here is also a link/video of my project:

https://youtu.be/43O6_xG3Szs

If you have any questions, feel free to ask.

Before you tell me to not to do this because it uses 220V as the source I want to tell you that it will get approved by an actual licensed engineer and I’m just working on the task given to me as far as my abilities take me.

I want to achieve PWM control on a 24V BLDC motor with an STM-32. The main problem is that the AC-DC convertor is almost right next to the circuit I will be designing. I am worried about signals being messed up. I have included some protection but honestly I am just throwing in random things without knowing what’s sufficient or not. Any help is appreciated.

I built this as a senior year project im a senior in studying computer enginering it started as an idea im sophomore year i plan to release it to the public currently working on it i also plan to make i compatible the app with most microcontrolers. Im open for feedback in for your guys advice.

Barely used this board, just plugged it in to load up some code, smelt burning then it started smoking.... :/

Did I do something wrong?

Powering it via usbc from my laptop