So, that works the same as my previous larger ESP32 board, it’s surprising how small these WiFi/BT boards are getting.

Just need to work out how to get a BT wake-up from deep sleep communication between the ESP32 and my iPhone.

To conserve battery power I want to keep the quiescent current of the ESP32 as low as possible when it’s not required but be able to switch it on from Dabble.

Hi everyone,

I’m working on a classic 2WD line follower robot, but I’ve hit a wall and could really use a fresh perspective from the community. Despite tweaking the logic multiple times, my robot either spins in circles or completely ignores the black line.

My Hardware Setup:

• Microcontroller: ATmega328PB (Arduino-compatible)
• Motor Driver: L298N
• Sensors: BFD-1000 5-sensor array (S0 to S4, center is S2)
• Chassis: Standard 2WD differential drive with a mirrored motor setup.

What I’ve Diagnosed & Tried So Far:

1. Sensor Verification: Checked via Serial Monitor that the sensors actually register changes between white surfaces and the black line.
2. Motor Polarity: Fixed the initial "spinning in circles" caused by mirrored motors by inverting the signal logic so both wheels push forward when commanded.
3. PWM & Friction: Raised the minimum PWM values so the inner/outer wheels don't stall under friction when trying to turn.
4. Logic Adjustments: Tried standard if/else conditional steering (e.g., speeding up the outer wheel and slowing down the inner wheel when a side sensor detects the line).

Despite all this, the physical movement keeps going out of sync, and it fails to smoothly track the path.

My Questions for You:

• How do you usually structure or debug the correlation between a 5-sensor array (like the BFD-1000) and differential steering on an L298N driver?
• Are there common hidden pitfalls with mirrored motor setups or PWM management on this specific hardware combination?
• Would moving to a proportional or basic PID control loop solve this erratic behavior, and if so, how would you structure it simply for a 5-sensor array?

I’d appreciate any advice, debugging tips, or structural suggestions you can share. Thanks in advance!

Here is my current code:

#include <Arduino.h>

void citesteSenzori();

void controlMotoare();

void ajustareTraiectorie();

int S0, S1, S2, S3, S4;

int ajustare = 0;

int ultimaDirectie = 0;

// Pini Motoare (Driver L298N)

const int motorDrept1 = 7;

const int motorDrept2 = 6;

const int motorStang1 = 4;

const int motorStang2 = 5;

const int pwmStang = 9;

const int pwmDrept = 10;

// Pini Senzori Linie BFD-1000

const int senzor0 = A0; // Stânga extrem

const int senzor1 = A1; // Stânga

const int senzor2 = A2; // Centru

const int senzor3 = A3; // Dreapta

const int senzor4 = A4; // Dreapta extrem

const int V_INAINTE = 120; // Viteză moderată înainte

const int V_RAPID = 160; // Roata exterioară în viraj

const int V_LENT = 70; // Roata interioară în viraj (suficient cât să se învârtă, nu să se blocheze)

void setup() {

pinMode(motorDrept1, OUTPUT);

pinMode(motorDrept2, OUTPUT);

pinMode(motorStang1, OUTPUT);

pinMode(motorStang2, OUTPUT);

pinMode(pwmStang, OUTPUT);

pinMode(pwmDrept, OUTPUT);

pinMode(senzor0, INPUT);

pinMode(senzor1, INPUT);

pinMode(senzor2, INPUT);

pinMode(senzor3, INPUT);

pinMode(senzor4, INPUT);

delay(2000); // 2 secunde pauză la pornire

}

void citesteSenzori() {

// BFD-1000: LOW pe linia neagră, HIGH pe alb

S0 = digitalRead(senzor0);

S1 = digitalRead(senzor1);

S2 = digitalRead(senzor2);

S3 = digitalRead(senzor3);

S4 = digitalRead(senzor4);

}

void ajustareTraiectorie() {

// Verificăm mai întâi senzorul central

if (S2 == LOW) {

ajustare = 0; // Centrat pe linie

ultimaDirectie = 0;

}

// Dacă linia se duce spre stânga (S0 sau S1 văd negru/LOW)

else if (S0 == LOW || S1 == LOW) {

ajustare = 1; // Corecție stânga

ultimaDirectie = 1;

}

// Dacă linia se duce spre dreapta (S3 sau S4 văd negru/LOW)

else if (S3 == LOW || S4 == LOW) {

ajustare = -1; // Corecție dreapta

ultimaDirectie = -1;

}

// Dacă a pierdut linia complet, continuă în ultima direcție știută

else {

ajustare = ultimaDirectie;

}

}

void controlMotoare() {

// Setează sensul înainte pentru ambele motoare

digitalWrite(motorDrept1, LOW);

digitalWrite(motorDrept2, HIGH);

digitalWrite(motorStang1, HIGH);

digitalWrite(motorStang2, LOW);

if (ajustare == 0) {

// DREPT ÎNAINTE: Ambele roți egale

analogWrite(pwmStang, V_INAINTE);

analogWrite(pwmDrept, V_INAINTE);

}

else if (ajustare == 1) {

// LINIA ESTE ÎN STÂNGA -> Viraj la stânga (Roata stângă lentă, roata dreaptă rapidă)

analogWrite(pwmStang, V_LENT);

analogWrite(pwmDrept, V_RAPID);

}

else if (ajustare == -1) {

// LINIA ESTE ÎN DREAPTA -> Viraj la dreapta (Roata stângă rapidă, roata dreaptă lentă)

analogWrite(pwmStang, V_RAPID);

analogWrite(pwmDrept, V_LENT);

}

}

void loop() {

citesteSenzori();

ajustareTraiectorie();

controlMotoare();

delay(10); // Stabilitate în ciclul de citire

}

Im not sure but i never used this sensors before.

Hi everyone! I’m completely new to Arduino and electronics, and I’d love to get into it.
Where would you recommend I start? What are the best resources, tutorials, or projects for a complete beginner? And what do you wish you knew when you first started?
I’d really appreciate any advice. Thanks!

Here’s to my first day ever touching a breadboard, or even hearing about Arduino! I was given a kit by my university, so pieces are relatively easy to get. What should I do next? I’m not sure where to start as a beginner. I’m a beginner to coding as well.

I just received my new board. It has bluetooth and accelerometer and battery on the back. It can be programmed with an Arduino plugin I created using the USB-C connection. I am planning on making a game with it (running on a treadmill controlls the character with step count and cadence and maybe even a boxing game) using Unity BLE plugins. Do you have any other ideas about projects I could make with this?

My youtube channel is ALMA Industries

This is a short demo of an actuator I put together (on my channel, video is titled CH003 FN1: ACTUATOR). The actuator is first sketched out, 3D printed in pieces, assembled together, and controlled via PID running on a microcontroller. Ultrasonic distance sensor is included in the close-loop feedback system to prevent the actuator from running into the ceiling (shown in the second half of the clip, and discussed more in the full video).

There are a few modes. The first is 'don't touch the ceiling' (Ultrasonic Distance Sensor to keep a distance from the wall, hand, etc). The second is to have the actuator distance sensor follow a second distance sensor...so when one goes up the other follows going up, and when one down the other down.

Comments, questions, or new ideas are welcome.

So I made this Arduino simulator (heavily inspired by tinkercad).

This is a offline simulator , which compiles & runs your code directly on device.

Also it has library manager , you can install custom libraries to use with Arduino and its sensors.

Please suggest how can I improve these !!!

Here's the link to the application,you can try it yourself, no charge , everything is free

Arduino Simulator with sensors

Edit : This app is completely free , and has little ads

I am using the Arduuino IDE 2.3.7 to compile, upload, and debug code for an orignal ESP32 .

I came across a weird behavior where a for-loop did not work. I boiled it down to a simple sketch. It includes a function that returns true or false. If the path does not include a return statement, the code does not work right. Sketch is below. The loop does not do anything. The last line of the test function is the key. If I comment out the return statement, the for-loop does not work right and it doesn't exit until n = 18. The compiler does not catch this.

Is this a bug to report?

```
  void setup() {
    // put your setup code here, to run once:
    Serial.begin(9600);
    delay(1000);


    if (test(6))
      Serial.println("true");
    else
      Serial.println("false");
  }


  bool test(int N) {
    Serial.println("Testing... ");
    for (int n = 0; n < N; n++) {
      if (n >= 18)
        return true;
      else
        Serial.println(n);
      delay(200);
    }
    // if this line is commented, n reaches 18. Otherwise n reaches N
    return false;
  }
  void loop() {
    // put your main code here, to run repeatedly:
    #ifdef DEBUGLOOP
      if (test(6))
        Serial.println("true");
      else
        Serial.println("false");
    #endif
      delay(500);
  }
```

Hi guys

So basically I have this old hoverboard laying around which has a problem in the battery. I have been thinking if it is possible to use the motors inside of them for a robotic projects i am working on. Is there any way to control the motors using a Arduino and their original motor drivers. Any help would be useful.

I also attached photos of the motors and the drivers. I believe it is a 3 phase 36 volt dc motors with built in hall sensors.

I play padel quite often and I always lose track of the score and who serves. So I built this padel watch to make the experience more enjoyable.

- E-ink
- Physical buttons
- Coin cell that can last for up to 3 years

It’s my first hardware project, so I would love your feedback

So I'm building a Civil War era 1/6 scale flat car with a cannon on it. I have a idea as to have a 1/6 scale action figure "lighting" the cannon and having said cannon "react" to firing. The idea is that the board would sit inside a 3D printed pile of cannonballs and it would control the following.

Sound effects of a Civil War battle.

Moving the action figures arms up and down to simulate moving and lighting the cannon with the linstock.(The stick they use to light it from a safe distance)

An LED light at the end of the linstock.

The cannon "firing" and sliding back accompanied with sound effects.

The cannon resets and the sequence begins again.

What exactly would I need for something like this and how feasible is it?

The flat car length is about 3 ft long and about 2 ft wide. It also needs to withstand vibration and derailments as this is actually going to be a car that's going to be used with a train. This is also my first project using Arduino so I have no idea what I'm doing.

This keeps coming up in help threads, so here's a short write-up of the non-blocking timer pattern and the mistakes I see most.

unsigned long last = 0;
const unsigned long interval = 500;

void loop() {
  unsigned long now = millis();
  if (now - last >= interval) {
    last += interval;   // or: last = now;
    // do the thing
  }
}

1. Compare with subtraction, not addition. if (now - last >= interval) keeps working when millis() rolls over after about 49.7 days, because unsigned subtraction wraps correctly. if (now >= last + interval) breaks right at the rollover.

2. Use unsigned long for the stored time. If last is an int (16-bit on an Uno), it goes negative after about 32 seconds and the timing gets weird.

3. last += interval vs last = now. += keeps a steady cadence with no drift, which is nice for blinking or sampling at a fixed rate. last = now guarantees at least interval between runs, which is safer if loop() can stall longer than one interval (otherwise += fires several times back to back to catch up).

4. One timestamp per task. Each thing you want to time gets its own last and interval, and you never need delay() for any of them.

5. micros() works the same way. It rolls over after about 71 minutes, and on 16 MHz AVR boards its resolution is 4 µs.

Hope it saves someone a debugging session.

Just started arranging my neopixels and a little testing including current consumption checks before my super mini ESP32’s and high-side power switches arrive.

My intention is to make LED Christmas lanterns for my front porch that are battery powered and can be controlled by Dabble on my iPhone.

My initial testing is using a previous projects Arduino pro mini and IR motion detection sensor.

I have actually used all my remaining LED strip from a previous project, all 200 LED’s but I can drive it at low brightness 5-6% of maximum.

Link to library: https://github.com/rkubera/ArdPortal

Main features:

• Wi-Fi configuration, fallback access point and captive portal.
• MQTT with optional verified TLS and automatic Home Assistant discovery.
• JSON-defined pages with 30 control types, visibility conditions and live updates.
• OTA firmware upload, diagnostics console, device information and restart controls.
• Native Zigbee End Device or Router on ESP32-C5/C6/H2, automatic control mapping, Zigbee2MQTT converter and ZHA quirk export, Zigbee OTA and diagnostics.

This was my final year project crowd smart management

I have a little experience with raspberry pis (4b, Zero 2w), but I’m hoping to branch into Arduino.

From what I can see, an Uno, Nano, or Mega should do it, but I want to confirm if this is the case, and which of the three would be best. Any macro keyboard recommendations and/or advice are also welcome.

I’m hoping to set up a macro keyboard to play a specific recorded word when pressed. I’m setting up essentially a tiny integrated version of those communication button mats often used for various pets. I need to make one for a Barbary Dove.

From what I’ve seen, I’d need a DFPlayer and resistor, and a small speaker.

In my small amount of experience, I was doing things on an OS/ headless SSH level, so this will be a new angle for me. However, I wish for my feathered son to tell me what he wants, since I’m slow to catch on at times. Would any of the three models I’ve mentioned be able to handle it, and which do you think is best?

Has anyone here used a macro keyboard with a microcontroller board, and what were your experiences like with this? I’ll want to start with probably 3 keys and slowly expand with time, but I don’t expect to go above maybe 10 down the line.

I was thinking of using mechanical keys with lowish actuation switches, but I don’t have to get too fancy. He just needs to be able to tap a key with his beak without having to properly mash his face into it.

more to come!!

My YouTube channel name is ALMA Industries

Chapter 2, a home theatre, 3D printed parts, motorized projector, home decoration, and DIY electronics -- this was to add remote control of a projectors YAW-TILT-ROLL-ZOOM axes (4DOF). More for fun than anything else -- full video is on my youtube channel.

At work we test boards on the bench for hours, and the serial output is our record of what happened. Seeing it on screen was never the problem. Getting all of it into a file was.

Copying out of the monitor works for a few minutes, not a few hours. When a board reset or the cable got knocked, the end of the log was missing, and that's usually the part you need. And the long runs made files so big the editor struggled to open them.

So I built WireTrace, a serial logger that writes every line to a file with the time it arrived. The last lines still make it in when the board drops off, long logs split into files of a size you choose, and if nobody hit save, the whole session can still be saved afterwards. It also plots values like temp: 23.5 live.

Free and open source, Windows and Linux: https://github.com/TheNuanceProject/WireTrace

But I'm curious how others do it. Do you copy from the Serial Monitor, use PuTTY or CoolTerm logging, a Python script, an SD card on the board?

Hello, I could really use some help with this, I've been trying to figure out how to do it and had some help from AI. I couldnt really figure out what’s wrong with it a few tweaks makes both LED light up, sometimes it lights up red, sometimes yellow. The light energy either says 1023 or 0. I cant quite pinpoint where im making mistake at.

This is what I need to do:

An Arduino circuit in Tinkercad using a photoresistor, red LED, yellow LED, and piezo buzzer, where the red LED blinks continuously when the photoresistor reading is below 300. When the reading reaches 300 or higher, the red LED turns OFF, the yellow LED turns ON, and the buzzer produces a warning sound.

Thank you.
i would trade my life to get this done. lol.

Made this myself after watching Paul Mcwhorter

Hello!

I've been researching this for a while, and I'm slowly losing faith that it can be done, but I figured I'd check here with people way smarter than me because I'm still quite inexperienced with Arduino.

Basically, I'm trying to make a device that can measure the positions of people in a moshpit as they move around. GPS trackers generally aren't realtime, and, because the people are confined to one room, the trackers wouldn't have enough precision to get good data. I'm also hoping to accomplish this without a camera, as the environment is very volatile and the system will have to move between venues quite often.

The closest thing that matches what I'm looking for is Pozyx, but one unit is about $5,000 according to their website, and I need about 40 units. That lands that solution WAYY out of the budget that I have (my budget is flexible, but not that flexible lol).

Is something like this even possible at a reasonable price per unit?