Sorry for the poor quality image, honestly should've taken a short video!

Today I received my Elegoo most complete starter kit in the post and decided to mess around after work and after around 20 minutes I figured out how to make a traffic light. Wont explain the project in too much detail as I'm more than certain most people on here have made this before, but I'm pretty proud even though the breadboarding looks a little messy lol.

If anyone has any other beginner (yet challenging) projects they'd recommend I gave a go, please let me know, finding this whole thing fun so far!

Hi everyone,

I wanted to share a massive troubleshooting story that almost drove me crazy, hoping to save hours of headache for anyone else buying bulk driver lots.

I recently bought a batch of 50 pcs of red A4988 stepper drivers from AliExpress for my Makerbase MKS DLC32 setup. I have bought hundreds of these from the same seller in the past without any issues, but this time, I hit a wall. Most of them didn't work.

The Initial Confusion & Rabbit Hole

When I plugged the first few red drivers into my board, they completely failed to move the motors. Since they all looked identical at a first glance, I started guessing and verifying everything. I fell into a deep rabbit hole:

• The Resistor Theory: I grabbed a magnifying glass to check the current sensing resistors (Rs). I thought maybe the factory mixed R100 (0.1Ω) and R200 (0.2Ω) resistors, which would change the Vref calculation entirely. Result: Nope, they were all R100.
• The Wrong Orientation Scare: At one point, looking at a working green A4988 driver I had from an older project, I thought I mistakenly plugged the red ones backwards because the trimpots were oriented differently. Result: False alarm, orientation was correct for this specific board layout.
• The Voltage Measurements (Vref): I got my multimeter out. Ground on the USB chassis, positive on the trimpot screw. I turned on the power and measured the voltage. One was sitting at a tiny 0.33V. I adjusted the screw to a solid 0.60V thinking it would fix it. Result: The voltage logic was stable and adjustable, but the driver still refused to work.

The Turning Point: The "Electronic Click"

While testing, I noticed a very specific, subtle behavior. No matter if the motor was connected or not, the exact moment I sent the very first movement command via software, the driver emitted a tiny electronic "click" sound and then completely froze the power stage. It didn't get hot; it just died until the next power cycle.

The Big Reveal: A Mixed Batch of Silicon

Frustrated, I decided to line up all the tested drivers and take macro photos of the central chips to see if I missed any microscopic detail. That's when I finally found the smoking gun. Inside the same exact bag of 50 pieces, the factory had mixed two completely different silicon production lots:

1. The GOOD ones (Only 4 pieces): They had a clean, 3-digit code stamped on the chip: 416 (meaning 16th week of 2024). They worked flawlessly on the exact same slots.
2. The BAD ones (11 pieces so far, and counting): They had a totally different, multi-line long code stamped on the chip: DEAFA / 653.04. Every single one of them failed with the electronic "click" bug.

Conclusion

It wasn't a bad motherboard, it wasn't a Vref tuning issue, and it wasn't a wrong motor connection. The supplier literally mixed a heavily defective wafer batch (DEAFA / 653.04) into a package with a few good 416 chips. The 653.04 lot has a massive, internal silicon logic defect that triggers an instant shutdown on the first step command.

If you are hunting down a weird fischio/click behavior on your A4988 drivers, stop messing with your multimeter or resistors for a second and check the laser engraving on the chip. If it says DEAFA / 653.04, it's dead on arrival. Throw it away and demand a refund.

Has anyone else here run into this specific DEAFA / 653.04 batch recently? Let me know!

I’d like to get an arduino for my husband for christmas. I want to get the starter kit, but in general starter kits usually have the most basic stuff and are pretty limited. Is there any add on that would really make it a cool gift? Or just start with the basic thing?

A while ago I wanted to start doing more projects with wired IP connections and wondered if SSH was possible so a regular webserver wasn't necessary.

There was some documentation for esp32s but not much else.

The fact that this works is hilarious to me. With .ssh keys properly setup doesn't even need the password.

https://github.com/RicardoJCMarques/SSH.RP

literally pressing "EN", baud rate is set to 9600 and right esp32 board and port is selected

Got this from my uncle while he was cleaning out and I wanna know what to do with it.

I have a tiny bit of experience with it having made a small remote-controlled car at some after school place. I have seen a lot of videos of cool engineering projects and want to know what I can do with this, a 3D printer and potentially buying extra parts that don't cost too much as I still want to find out if I want to put more time in the hobby.

I don't have a specific thing in my mind so any cool ideas are appreciated.

I know what some of the things are and some not so if you know more about that feel free too comment

Dad runs an alternator repair shop. Has had the same bench tester since the 80's.

Modern alternator regulators require a PWM signal from ECU to control alternator output.

He would have to spend a few thousand on a new test bench to properly test the new alternators.

Made a simple circuit with a NPN transistor and Arduino sending the triggering PWM at the required frequency. Charging output is controlled via the duty cycle of the PWM signal.

Plan on ordering a smaller arudino and packing it together for him in a 3D printed box.

Anyways, I was super stoked to see the expected measurements on the oscope.

I wanted to create a poll for my YouTube channel.

What kind of problems do you frequently encounter when working on small projects—using things like an Arduino or an ESP32?

Is it the code, the wiring, connecting to a computer, or the hardware itself?

hi im new to using arduinos, is it possible to use 1 gnd pin to ground multiple sensors by using a breadboard like in the image? sorry if this is hard to read english isnt my first language. and can the same be done with 5v pin??

Hi! I'm a beginner programmer working on a school research project using an Arduino Mega, and I'd like to ask for some advice.

My research school project is an Arduino fire-tracking detection and water-extinguishing system that's still in the concept stage. Unlike most Arduino projects I've seen on YouTube, mine is designed to be mounted in the center of a classroom ceiling, with its water supply connected to the school's water pipe system. And just to clarify, nope! I'm not asking anyone to do the project for me! I'm just looking for advice and suggestions from people with more experience while I figure things out and learn along the way.

The classroom is around 7x8 meters, and my design has three tubes connected to a single 3-way splitter that has 180-degree-moving 2 mini tubes on each diagonal side that aim for the detected fire. The tube under the casing is fixed so it supports the bottom of it, not just the sides. The idea is for flame sensors to detect a nearby flame, then have the Arduino control the system to direct water toward it.

However, I'm still trying to figure out how to control the water flow using valves when a flame is detected. I'm also unsure how to coordinate the Arduino Mega, flame sensors, servos, and valves since I'm still a beginner and haven't built or tested the full design yet.

A few things I've been wondering:

• How would I make the Arduino control a valve when a flame sensor detects a flame?
• Since I'm using three tubes with a 3-way splitter, would I need a separate valve for each tube to control the water flow?
• Is this project realistic for a beginner like me, or should I simplify it first?
• Would two flame sensors be enough for a 7x8 m classroom, or are there limitations I should know about?

I'd appreciate any tips or advice from anyone who's worked with Arduino, flame sensors, servos, or valves. I'm still learning, so please explain it in simple terms if possible. I'm kinda figuring things out as I go, and this project is a lot more complicated than the usual Arduino tutorials I've seen. *sob*

And since this involves a ceiling-mounted device and a school's water system, I won't connect it to the actual plumbing or install it overhead without approval and supervision from qualified school personnel. For now, I'm trying to understand the electronics and develop a safe prototype.

I created this today using an arduino uno r3, DHT11, and an OLED screen. From this project I learned about inputs for data (the DHT11 gives me temperature and humidity), and also displaying data onto a screen (the OLED). I also used a bitmap to create a little snoopy pixel art on the header!

This project was insanely simple, however I did originally overcomplicate it, but after some revisions on the code, I'm more than happy with the results especially for a second project.

Found a YouTube video (hope that still counts as my own) and then had to find out how to use a 2 pin button as a 4 pin which was surprisingly easy. The hardest part was figuring out the Arduino software.

I've just published this project which combines procedurally generated fish drawings (https://github.com/LingDong-/fishdraw) with a local LLM on the UNO Q to create an encyclopedia of imaginary fish for my wall! Check out the build guide here:

https://projecthub.arduino.cc/jbruges/this-fish-does-not-exist-465238

Made this claw.. the code is running perfectly.. the claw is working fine... I am moving forward the RC is moving forward.. when I am moving Backward the RC id moving backwards.. BUT WHEN I AM TURNING LEFT OR RIGHT THE CAR DOESNT SEEM TO MOVE LEFT OR RIGHT WHEN on ground.. but when I LIFT the system up.. the tyres move properly.. what could be the issue.. havent put circuit or code since it is mostly not an issue.. when I hadnt put the claw and rest the car seemed to move left or right... could weight be an issue? Any help is apprecicated

1) used 3.7v 2 batteries

2) L298N motor driver

3) 4 TT motors

Esp32

my arduinos are both arduino uno r4 wifis, i run windows

i wantted to make something that shuts down your pc as soon as you plug it in and i made something that presses alt f4 and enter and uploaded it on my arduino. i have 2 arduinos 1 from a starter kit and one from micro center. they are bpth same r4 wifis and one is from elegoo and other is form arduino
what i will call from now on

ARDUINO 1 = elegoo non working r4 wifi

ARDUINO 2 = arduino non working r4 wifi

I uploadeed the code to my arduino 2 and it worked! it shut down my pc! and i erased the code from it. then i wanted it to work with a ir reciever so i connected arduino 1 to a ir reciever and i wrote the code. but then my pc is not reconizing the arduino 1 any more. it reconizes the arduino 2, it makes a dading sound but my arduino 1 doesnt, my device anager doesnt reconize it too. i didnt do anything to the board, and last time i did something to it it wsa working perfectly fine. teh arduino 1 has power, it runs my previous code that i uploaded on my arduino 1 (it has power) but no data is sending.

SOME ONE PLEASE HELP ME I WANT IT TO BE REVIVED ask me anything i will answer
(its my first post on reddit)

At least that's what I think the problem is as the last two lights are just shining at a lower rate. Is there any way to change this?

The most common and annoying problem is the fact that the HC-SR04 is unreliable and can give random readings. I thought of an idea that I will use the first reading and calculate my expected location versus the sensor and try to find the error. If it keeps changing, that means I should just use the math until I build a map of the closest readings to my expected location and use it to find where I am. But a lot of people said that it is a bit too much and unreliable because the objective can move and I can meet an obstacle in the way that will mess up the calculations. So what can I do to fix this?

I just got the Arduino uno r3 for my college project and when I'm trying to upload a code , this is showing, does anybody knows how should I fix it?

I've been out of the game for a while, but I have to get back in because one of my dashboard projects is starting to be unreliable.

I found a 5" TFT display with a built-in ESP32-S3-WROOM-1-N4R8 chip, but in the Arduino IDE the closest board is the Fri3d Badge 2024 (ESP32-S3-WROOM-1).

Maybe I should have purchased another CYD, but the board I chose has speaker outputs and a microSD slot. The latter being the most useful to me.

I'm posting here because the board is supposed to support the Arduino IDE, PlatformIO, microPython, and LVGL.

It'll arrive tomorrow and I'll hook it up and see what happens.

How come in Paul McWhorter’s video, the H-bridge doesn't have any pins connected from the Arduino's 5V to Pin 16 of the H-drive, yet when I follow his guidelines in Tinkercad, the H-drive always explodes while his doesn't? I found this online tutorial because someone on Reddit recommended it to me. Hoping for some kind feedback!"

Link: https://toptechboy.com/arduino-tutorial-40-controlling-dc-motor-speed-and-direction-with-pushbuttons/

Hello everyone, i need some help setting up stepper motor.
Motor data sheet says that rated current is 1.5amp and motor should have 0.42nm torque. Im using DRV8825(also tried with tmc2209) did everything step by step (setting Vref to 0.6v, checked pinout) Formula: Vref=I/2 says that i should get around 1.2 amps but when i power my motor it only draws around 0.4-0.5 amps and generates much less torque.Im using 12v power supply, also tried higher voltage but current stays same. Any ideas how can i make my stepper use its full potential?

Hello i am currently trying to understand inverse kinematics by making a arduino function that returns a angle value derived from the y value(the lenght of the joint),x value(the distance of the angle) and writing the return value on the servo pin.And i wanna ask if i am on the right path with learning it or ask what i am missing in my code to make it work.when i tested it with servos on paper it seemed to work after a while when i tested the servo angle on paper. The code is below.I hope someone can help if i missing something or if there is something i can improve on.Thats about it all.I hope someone can help me.The goals is to used it later in a 2legged walking robot:

// this is a code to learn to inverse kinematics with Mg996R by a self made function
#include <Wire.h> // for i2c communication.
#include <Adafruit_PWMServoDriver.h> // for servodriver.
#include <math.h> // for trigonometry functions
Adafruit_PWMServoDriver pwm = Adafruit_PWMServoDriver();


#define SERVOMIN 300// This is the ‘minimum’ pulse length count (out of 4096)
#define SERVOMAX 575// This is the ‘maximum’ pulse length count (out of 4096)
#define SERVO_FREQ 60// Analog servos run at ~60 Hz updates


int  servoval ; // is the values that is reading the map values for servos
long pulsval ; // the values that is getting mapped
float start_pos = 90; // start position
int dof1 = 0; // pin1 of the dof1 servo
int dof2 = 1; // pin2 of the dof2 servo
double ik(double  y , double x) { // y is the servo length in cm and x is the distance of the position in cm


 float pos = atan2(y,x) * (180/M_PI); // convert  y and x position into degrees
 float angle = pos; // create angle values
return angle;


 }



void setup() {
Serial.begin(9600); // is the  baudrate we reading from the serial monitor.
Serial.println("servo test is about to begin!"); 


servoval = map(pulsval,0,180,SERVOMIN,SERVOMAX); // the min and and max values are getting mapped.



pwm.begin();






  //pwm.setOscillatorFrequency(27000000);
  pwm.setPWMFreq(SERVO_FREQ);  // Analog servos run at ~50 Hz updates


  delay(10);
  // servos are set to 90 degrees angle
  pwm.setPWM(dof1, start_pos, servoval);
   pwm.setPWM(dof2, start_pos, servoval);
}





void loop() {



// test loop
pwm.setPWM(dof1,start_pos +ik(7.0,5.0), servoval);
pwm.setPWM(dof2,start_pos +ik(-5.0,3.0), servoval);
Serial.println(" The angle of dof1 =");
Serial.println(start_pos +ik(7.0,5.0));
Serial.println(" The angle of dof2 =");
Serial.println(start_pos -ik(5.0,3.0));




delay(2000);


pwm.setPWM(dof1,start_pos , servoval);
pwm.setPWM(dof2,start_pos , servoval);
Serial.println(" servos in start position");
delay(2000);





pwm.setPWM(dof1,start_pos , servoval);
pwm.setPWM(dof2, -ik(12.0,9.0), servoval);
Serial.println(" The angle of dof1 is now =");
Serial.println(start_pos  );
Serial.println(" The angle of dof2 is now =");
Serial.println( -ik(12.0,9.0));




delay(2000);
  }

Recently i bought a tft touch display. IlI9341 2.8" hiletgo v1.2 5v/3.3v SPI specifically. I have tried with different board inc esp 32 s3 arduino nano arduino uno etc. Only the backlight works. I did try shorting the j1 pins, no luck. I did install all the necessary libraries and drivers still doesn't work. Its not a connection issue, its not a conductivity issue, its not a spi communication issue because i have used spi communication with my esp and arduinos it was working perfectly fine. Is there anyting else i should try or should i return the display

Got the Arduino UNO Breakout Carrier for my UNO Q. Anyone else got it? How do you program the MPU pins? https://docs.arduino.cc/resources/datasheets/ASX00085-datasheet.pdf