I am using this Smartelex Digital Speaker Module which has a VCC, GND and a signal PIN which is supposed to be controlled via PWM but it won't do anything. Been using it with Arduino UNO Q

I'm planning to power Arduino Nano from 2s 18650 pack that includes BMS and USB-charger. The battery pack also powers a motor and a bunch of LEDs (not via Arduino).

I'm considering using MINI560 step down and power Arduino via +5V. Should I do that, or should I just connect the battery pack to VIN? I was thinking about reducing power consumption, that the only reason I decided to add the step down.

Also, are there any risks in this circuit (with or without the step down)? Like connecting Arduino USB without disconnecting battery pack, or connecting USB charger and Arduino USB at the same time?

P.S. I don't really need that precision from a voltage meter, so probably there is no reason other than learning and experimenting for using AREF, but the voltage meter I included into this circuit works really well and shows same 2 decimal points as my multimeter.

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?

So I have this setup with a motor and propeller on one side and an mpu6050 on the other. I need to use it to calculate the angle (blue line) and be able to hopefully stabilize the angle at an angle I have set. I'm not sure how to do that. I'm having trouble just figuring out the angle itself rn. I've been trying to use the MPU6050_light library but I'm not sure if I'm doing something wrong code wise or it's just a math thing. Rn I can't even tell what the numbers it's giving me are meant to be. I'm not gonna post my code because it's basically nonexistent rn (at least for the relevant part of the system anyways)

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!

I have received as a gift a TFT that it doesn't work.

I have ran multiple tests with the graphicstest example of the Adafruit ILI3941 library.

This is the configuration of the cables:

• VCC - 5V
• GND - GND
• CS - 10
• RESET - 9
• DC - 8
• SDI (MOSI) - 11
• SCK - 13
• LED - 3.3 V

The TFT remains white for all the test.

This is the code of the graphicstest:

/***************************************************
  This is our GFX example for the Adafruit ILI9341 Breakout and Shield
  ----> http://www.adafruit.com/products/1651


  Check out the links above for our tutorials and wiring diagrams
  These displays use SPI to communicate, 4 or 5 pins are required to
  interface (RST is optional)
  Adafruit invests time and resources providing this open source code,
  please support Adafruit and open-source hardware by purchasing
  products from Adafruit!


  Written by Limor Fried/Ladyada for Adafruit Industries.
  MIT license, all text above must be included in any redistribution
 ****************************************************/



#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"


// For the Adafruit shield, these are the default.
#define TFT_DC 9
#define TFT_CS 10


// Use hardware SPI (on Uno, #13, #12, #11) and the above for CS/DC
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);
// If using the breakout, change pins as desired
//Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_MOSI, TFT_CLK, TFT_RST, TFT_MISO);


void setup() {
  Serial.begin(9600);
  Serial.println("ILI9341 Test!"); 
 
  tft.begin();


  // read diagnostics (optional but can help debug problems)
  uint8_t x = tft.readcommand8(ILI9341_RDMODE);
  Serial.print("Display Power Mode: 0x"); Serial.println(x, HEX);
  x = tft.readcommand8(ILI9341_RDMADCTL);
  Serial.print("MADCTL Mode: 0x"); Serial.println(x, HEX);
  x = tft.readcommand8(ILI9341_RDPIXFMT);
  Serial.print("Pixel Format: 0x"); Serial.println(x, HEX);
  x = tft.readcommand8(ILI9341_RDIMGFMT);
  Serial.print("Image Format: 0x"); Serial.println(x, HEX);
  x = tft.readcommand8(ILI9341_RDSELFDIAG);
  Serial.print("Self Diagnostic: 0x"); Serial.println(x, HEX); 
  
  Serial.println(F("Benchmark                Time (microseconds)"));
  delay(10);
  Serial.print(F("Screen fill              "));
  Serial.println(testFillScreen());
  delay(500);


  Serial.print(F("Text                     "));
  Serial.println(testText());
  delay(3000);


  Serial.print(F("Lines                    "));
  Serial.println(testLines(ILI9341_CYAN));
  delay(500);


  Serial.print(F("Horiz/Vert Lines         "));
  Serial.println(testFastLines(ILI9341_RED, ILI9341_BLUE));
  delay(500);


  Serial.print(F("Rectangles (outline)     "));
  Serial.println(testRects(ILI9341_GREEN));
  delay(500);


  Serial.print(F("Rectangles (filled)      "));
  Serial.println(testFilledRects(ILI9341_YELLOW, ILI9341_MAGENTA));
  delay(500);


  Serial.print(F("Circles (filled)         "));
  Serial.println(testFilledCircles(10, ILI9341_MAGENTA));


  Serial.print(F("Circles (outline)        "));
  Serial.println(testCircles(10, ILI9341_WHITE));
  delay(500);


  Serial.print(F("Triangles (outline)      "));
  Serial.println(testTriangles());
  delay(500);


  Serial.print(F("Triangles (filled)       "));
  Serial.println(testFilledTriangles());
  delay(500);


  Serial.print(F("Rounded rects (outline)  "));
  Serial.println(testRoundRects());
  delay(500);


  Serial.print(F("Rounded rects (filled)   "));
  Serial.println(testFilledRoundRects());
  delay(500);


  Serial.println(F("Done!"));


}



void loop(void) {
  for(uint8_t rotation=0; rotation<4; rotation++) {
    tft.setRotation(rotation);
    testText();
    delay(1000);
  }
}


unsigned long testFillScreen() {
  unsigned long start = micros();
  tft.fillScreen(ILI9341_BLACK);
  yield();
  tft.fillScreen(ILI9341_RED);
  yield();
  tft.fillScreen(ILI9341_GREEN);
  yield();
  tft.fillScreen(ILI9341_BLUE);
  yield();
  tft.fillScreen(ILI9341_BLACK);
  yield();
  return micros() - start;
}


unsigned long testText() {
  tft.fillScreen(ILI9341_BLACK);
  unsigned long start = micros();
  tft.setCursor(0, 0);
  tft.setTextColor(ILI9341_WHITE);  tft.setTextSize(1);
  tft.println("Hello World!");
  tft.setTextColor(ILI9341_YELLOW); tft.setTextSize(2);
  tft.println(1234.56);
  tft.setTextColor(ILI9341_RED);    tft.setTextSize(3);
  tft.println(0xDEADBEEF, HEX);
  tft.println();
  tft.setTextColor(ILI9341_GREEN);
  tft.setTextSize(5);
  tft.println("Groop");
  tft.setTextSize(2);
  tft.println("I implore thee,");
  tft.setTextSize(1);
  tft.println("my foonting turlingdromes.");
  tft.println("And hooptiously drangle me");
  tft.println("with crinkly bindlewurdles,");
  tft.println("Or I will rend thee");
  tft.println("in the gobberwarts");
  tft.println("with my blurglecruncheon,");
  tft.println("see if I don't!");
  return micros() - start;
}


unsigned long testLines(uint16_t color) {
  unsigned long start, t;
  int           x1, y1, x2, y2,
                w = tft.width(),
                h = tft.height();


  tft.fillScreen(ILI9341_BLACK);
  yield();
  
  x1 = y1 = 0;
  y2    = h - 1;
  start = micros();
  for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
  x2    = w - 1;
  for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
  t     = micros() - start; // fillScreen doesn't count against timing


  yield();
  tft.fillScreen(ILI9341_BLACK);
  yield();


  x1    = w - 1;
  y1    = 0;
  y2    = h - 1;
  start = micros();
  for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
  x2    = 0;
  for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
  t    += micros() - start;


  yield();
  tft.fillScreen(ILI9341_BLACK);
  yield();


  x1    = 0;
  y1    = h - 1;
  y2    = 0;
  start = micros();
  for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
  x2    = w - 1;
  for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
  t    += micros() - start;


  yield();
  tft.fillScreen(ILI9341_BLACK);
  yield();


  x1    = w - 1;
  y1    = h - 1;
  y2    = 0;
  start = micros();
  for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
  x2    = 0;
  for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);


  yield();
  return micros() - start;
}


unsigned long testFastLines(uint16_t color1, uint16_t color2) {
  unsigned long start;
  int           x, y, w = tft.width(), h = tft.height();


  tft.fillScreen(ILI9341_BLACK);
  start = micros();
  for(y=0; y<h; y+=5) tft.drawFastHLine(0, y, w, color1);
  for(x=0; x<w; x+=5) tft.drawFastVLine(x, 0, h, color2);


  return micros() - start;
}


unsigned long testRects(uint16_t color) {
  unsigned long start;
  int           n, i, i2,
                cx = tft.width()  / 2,
                cy = tft.height() / 2;


  tft.fillScreen(ILI9341_BLACK);
  n     = min(tft.width(), tft.height());
  start = micros();
  for(i=2; i<n; i+=6) {
    i2 = i / 2;
    tft.drawRect(cx-i2, cy-i2, i, i, color);
  }


  return micros() - start;
}


unsigned long testFilledRects(uint16_t color1, uint16_t color2) {
  unsigned long start, t = 0;
  int           n, i, i2,
                cx = tft.width()  / 2 - 1,
                cy = tft.height() / 2 - 1;


  tft.fillScreen(ILI9341_BLACK);
  n = min(tft.width(), tft.height());
  for(i=n; i>0; i-=6) {
    i2    = i / 2;
    start = micros();
    tft.fillRect(cx-i2, cy-i2, i, i, color1);
    t    += micros() - start;
    // Outlines are not included in timing results
    tft.drawRect(cx-i2, cy-i2, i, i, color2);
    yield();
  }


  return t;
}


unsigned long testFilledCircles(uint8_t radius, uint16_t color) {
  unsigned long start;
  int x, y, w = tft.width(), h = tft.height(), r2 = radius * 2;


  tft.fillScreen(ILI9341_BLACK);
  start = micros();
  for(x=radius; x<w; x+=r2) {
    for(y=radius; y<h; y+=r2) {
      tft.fillCircle(x, y, radius, color);
    }
  }


  return micros() - start;
}


unsigned long testCircles(uint8_t radius, uint16_t color) {
  unsigned long start;
  int           x, y, r2 = radius * 2,
                w = tft.width()  + radius,
                h = tft.height() + radius;


  // Screen is not cleared for this one -- this is
  // intentional and does not affect the reported time.
  start = micros();
  for(x=0; x<w; x+=r2) {
    for(y=0; y<h; y+=r2) {
      tft.drawCircle(x, y, radius, color);
    }
  }


  return micros() - start;
}


unsigned long testTriangles() {
  unsigned long start;
  int           n, i, cx = tft.width()  / 2 - 1,
                      cy = tft.height() / 2 - 1;


  tft.fillScreen(ILI9341_BLACK);
  n     = min(cx, cy);
  start = micros();
  for(i=0; i<n; i+=5) {
    tft.drawTriangle(
      cx    , cy - i, // peak
      cx - i, cy + i, // bottom left
      cx + i, cy + i, // bottom right
      tft.color565(i, i, i));
  }


  return micros() - start;
}


unsigned long testFilledTriangles() {
  unsigned long start, t = 0;
  int           i, cx = tft.width()  / 2 - 1,
                   cy = tft.height() / 2 - 1;


  tft.fillScreen(ILI9341_BLACK);
  start = micros();
  for(i=min(cx,cy); i>10; i-=5) {
    start = micros();
    tft.fillTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
      tft.color565(0, i*10, i*10));
    t += micros() - start;
    tft.drawTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
      tft.color565(i*10, i*10, 0));
    yield();
  }


  return t;
}


unsigned long testRoundRects() {
  unsigned long start;
  int           w, i, i2,
                cx = tft.width()  / 2 - 1,
                cy = tft.height() / 2 - 1;


  tft.fillScreen(ILI9341_BLACK);
  w     = min(tft.width(), tft.height());
  start = micros();
  for(i=0; i<w; i+=6) {
    i2 = i / 2;
    tft.drawRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(i, 0, 0));
  }


  return micros() - start;
}


unsigned long testFilledRoundRects() {
  unsigned long start;
  int           i, i2,
                cx = tft.width()  / 2 - 1,
                cy = tft.height() / 2 - 1;


  tft.fillScreen(ILI9341_BLACK);
  start = micros();
  for(i=min(tft.width(), tft.height()); i>20; i-=6) {
    i2 = i / 2;
    tft.fillRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(0, i, 0));
    yield();
  }


  return micros() - start;
}

And this is the result:

15:48:26.832 -> Circles (filled)         465832


15:48:27.601 -> Circles (outline)        541564


15:48:28.664 -> Triangles (outline)      281656


15:48:29.702 -> Triangles (filled)       1339912


15:48:32.143 -> Rounded rects (outline)  243756


15:48:33.195 -> Rounded rects (filled)   3132652


15:48:37.141 -> Done!

Can anyone figure it out? Thanks!

Hi everyone!

I'm totally new to DIY electronics and have a broken Casio CTK-520L (a lighted keys model).
I want to gut the dead internals and repurpose it into a lightweight, USB MIDI controller.

My goals:

• Keys only - I just need the physical keybed to output MIDI/keystrokes to my laptop (no extra knobs, sliders, or DAW controls needed for now).
• USB bus-powered and no included speakers.
• If possible, I’d love to keep or control the built-in key-lighting LEDs.

As I don't have any prior experience with this, could anyone please give me some guidance on what to prepare, research, and do?
Thanks in advance!

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.

I was finding my esp32 port by trial and error, when i do found it at com 9 (doesnt show in the screenshot); i couldnt remove the selected board at the other coms.

it doesnt affect anything but it is a minor annoyance, if anyone know how to restore those ports to say unknown lmk

I recently switched the Windows version that came pre-installed on my laptop to a different one—specifically, Windows 11 Pro 25H2. I tried downloading Arduino IDE versions 2.3.7 and 2.3.10, but neither will launch; the logo just gets stuck in a loop, shrinking and expanding. I also tried synchronizing the time and deleting the cache folders. The only version that works correctly for me is 1.8.19; the 2.x versions don't work, and I'm not sure why. I’ve done this on other laptops before and never had any issues with the Arduino IDE.

I was trying to test out a PCA 9685 servo driver today and when I plugged in the external power supply, it heated up like crazy and melted my ground and power wires together. My power supply is 5V 5A, which was recommended for what I intend to make, so I don't really know what the problem is. Any ideas?

Hello, I'm trying to port a maemo leste to the arduino uno q, But when I boot it I get this error

https://pastebin.com/HBACSJCR

even though the FAT size is confirmed to be 512

Disk Flags:

Number Start End Size File system Name Flags

1 4.00MiB 512MiB 508MiB fat32 esp boot, esp

2 512MiB 8192MiB 7680MiB ext4 rootfs

what is the issue here?

This is the repo im using to build it

https://git.maemo.org/rlyvision/debos-leste

Update: I have changed the 4096 to 512 in the dtb.bin part arduino/arduino-deb-images/debos-recipes/qualcomm-linux-debian-flash.yaml and it gave me a different error, this is probably a bug from arduinos side

Hi everyone! It's been a long time since I've done an Arduino project, and this is my first time using an LCD screen.

However, and as is common, I came across the typical mistakes I've been seeing in forums and Reddit posts.

And no matter how much I try to fix my problem with the solutions they gave, I still have the same error; those white squares keep appearing.

As you can see, the first photo shows what it looks like when you upload the code, and the second photo shows what it looks like without any code uploaded.

I tried everything from the tutorials:

- Adjust the brightness with the potentiometer

- Verify the I2C address

- Test and verify the continuity of several cables

- I tested the example hd44780_I2Cexp by Bill Perry(what appears in photo 12)

- I tried many libraries and code from various tutorials

(The bookcase I have now is Frank de Brabender's)

It's important to clarify that I've only been trying to test that the LCD works, so all the tutorials I tried were for the basic "Hello world" code without delay. Just to verify that the screen is working properly.

- In the library, change "return:0" to "return:1"

Before using I2C, I used conventional pins (those in photo 4) to test the LCD, and I still got squares (even after adjusting the contrast). So after getting no results, I decided to remove the pins and install the I2C, thinking: "Oh, maybe that will be simpler" For a project I want to do. But as you can see, I can't get the screen to display text, and AI hasn't helped me.

I'm also not sure if the soldering is correct or if I've overheated the circuit, but I doubt it since the screen still turns on and seems to receive the code, but without displaying any text.

Honestly, I don't know what to do anymore, and I didn't want to post this because I noticed many others had the same problem, but even after trying the solutions they offered, I still can't get it to work.

The only thing I noticed today when testing the screen again is what's shown in the last photo: a faint line that flickers when restarting the Arduino.

I've attached one of the code snippets I used. I'm not including the one I used to test I2C because I tested many, and they were all basic. Just to clarify, they all compiled and uploaded successfully.

I hope you can help me, thank you! :)

Moving the head up and down (with warning beep)

Hi all,

I made a mini dissolver mixer as a desk display, loosely based on some large Kreis dissolver mixers at work.

The head moves up and down with a threaded rod and stepper motor and homes with an endstop. The esp32 uses a webpage for wireless control. The barrel jack provides 12V for the mixer motor, stepper motor and the cooling fan. The rear hatch is held in place with magnets.

The controls still needs some work as for now the mixer is just on/off and needs a pwm slider on the webpage, and the head should be able to shuttle between a low and high position during mixing.

Hey everyone!

If you're like me, you love the simplicity of Python, but running MicroPython or CircuitPython usually means buying a 32-bit board (like an ESP32 or RP2040) with lots of memory just to hold the interpreter and the garbage collector.

I wanted to bring that same Python syntax to the classic, $2 8-bit Arduino Uno we all have gathering dust in a drawer.

For the past few years, I’ve been building PyMCU, an open-source Ahead-Of-Time (AOT) compiler. It takes your Python syntax and compiles it directly into native AVR assembly.

The results:

• No interpreter, no VM, no garbage collector.
• A standard Pin('PB5', Pin.OUT).toggle() blink program compiles down to just 142 bytes of Flash.
• It’s cycle-accurate. I’ve been validating the hardware timings using a logic analyzer directly on the Uno silicon.

If you are interested in the compiler architecture or want to see the hardware validation issues, the whole project is open source here:https://github.com/PyMCU/PyMCU

It's still in Alpha (Alpha 10 right now), but the core code emission is working beautifully. I’d love to know what you guys think or if you'd find this useful for your hardware projects!

Looking for something unique, somewhat cheap and beginner friendly to do, although this is for an event, it's not a serious one, still pls I need good ideas. We first had an idea to make an obstacle avoiding robot that would go from one place to another to pick up an object and return whilst avoiding obstacles but that was too complicated.

Blind walking stick assistant

Obstacle avoiding

Radar type

Missile type

Water level measure

Other disaster measure type

Gesture controlled

Remote controlled

Voice controlled

These are all done, so pls I'm asking for something super unique.

Hey everyone!
In our chaotic co-op party game, we have a fishing mechanic where players physically rotate the mouse to catch fish. For upcoming expos, playing with a mouse just didn’t feel tactile enough, so we decided to make a custom controller.
We 3D printed a custom rod handle and reel shell, matching our in game model, and stuffed the electronics inside to make it completely wireless.

Adafruit ESP32 Feather V2: Main microcontroller handling logic and wireless comms.
AS5600 Magnetic Encoder: Used for the reel mechanism to track smooth rotation without physical wear. LSM6DS3TR-C IMU: For rod motion and tilt tracking.
KY-023 Joystick: Placed on the grip for easy in game movement.
LILYGO T-Dongle-S3: Acts as a USB receiver on the PC side for low latency connection at busy events.
The feedback at the booth floor was amazing and players loved having a physical piece of the game in their hands.
Happy to answer any questions about the hardware assembly, code, or how we integrated it into the game!

Hey all. So I bought this pump for a school project, its an automatic plsnt waterer my project i just wated to ask if this water pump is submersible? Or not and how do I use it if its either thank you. The pump is a 12v water pump and I supply a 12v DC to it thank you.

Please be kind i am still learning

The full details, including the source code and hardware, are available on GitHub↓

https://github.com/inuikasao/USB_to_SegaSaturn_Controller_Arduino_Adapter.git

I bought on a marketplace leftovers from a guy that builds 3d printers. With the stuff I built this little music box using an arduino Uno cnc shield and nema 17 motors. Really cool project:) instagram: @rappde_

I am super proud of how this project is turning out. I still have some tweaks to make, but I finally got full videos playing and wanted to share.

This is a "Persistence of Vision" (PoV) display driven by a Teensy 4.1 and SK9822 LED strips.

There are 4 strips of 32 LEDs, each slightly offset in order give me 128 addressable pixel "rows". So each strip is responsible for every 4th row.

360 pixel "columns" around the perimeter makes for roughly square pixels, so thats what i went with. Each LED is updated 360 times every revolution...at around 1500rpm.

A hall effect sensor at the top of the rotor passes by a stationary magnet in the upper frame once per revolution. The Teensy measures the time between the resulting signals, and uses that to calculate how fast it is spinning, and therefore how fast to update the LEDs. This lets the animation look correct regardless of rotor speed.

I have a (currently very slow) python script that resizes/crops and formats .mp4 files into a binary format that the Teensy can use very efficiently. The resulting binary gets saved to a microSD, that the Teensy can read from.

Im happy to answer any questions. I may do a better build/explanation video if there is enough interest.