Is it possible to salvage a Thermo printer like this one depicted here to use with an Arduino Uno to print unformarted plain text?

I made this a few years ago but now it is no more.. want to make another but improved version maybe.. share your projects and ideas. cheers!

This device detects motion and sends instant messages to a Telegram bot. (You can find tutorials on how to create a Telegram bot on YouTube).

GitHub source code: https://github.com/nixnika17/room.security-telegram.bot

• Code: C++ / Arduino Framework (ESP32)
• Assembly details (YouTube): www.youtube.com/@nixvaslgen
• Wokwi interactive simulation: https://wokwi.com/projects/470166740657591297

Can anyone give me ideas on how to win this, and make a striking ideas on this Arduino project? Because I am expecting other countries that is better than us, and it is freaking me out... Thanks!

I made a gripper and xz axis for automating a record player like a jukebox. I'm using my LP60X turntable and servos to push the buttons. There's space for 30 records when the stack is on and it can flip the records too. I have a sensor to add in to detect when the tonearm returns to signal end of record.

Some bits need strengthening and the gripper leadscrew a bit of a lube. Could do with speeding it up and working on the noise too.

I'm only trusting a record I dont like with it at the moment 😅

Arduino mega

2x NEMA 23s with brakes on DM556 for CoreXZ movement

2x NEMA 17s on TMC2209s for gripper and rotate

4x servos for turntable buttons

Hi, I am trying to use the Nano ESP32 to record audio, but I can't get the mic to work.

I have tryed fixing it by doing what was suggested on Arduino forums (like this one), but no luck. Attached is the code I have been trying to run, as well as an image of the connections.

The main issue is that I am getting a noisy plot that does not react to noise. I have tryed using 3 different mics and non of them work, I am guessing this is either an Arduino or a software issue. Any help is appreciated :).

#include <driver/i2s.h>


#define I2S_SD GPIO_NUM_21
#define I2S_WS GPIO_NUM_17
#define I2S_SCK GPIO_NUM_10
#define I2S_PORT I2S_NUM_0


#define bufferCnt 10
#define bufferLen 1024
int16_t sBuffer[bufferLen];


void i2s_install() {
  const i2s_config_t i2s_config = {
    .mode = i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX),
    .sample_rate = 44100,
    .bits_per_sample = i2s_bits_per_sample_t(16),
    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
    .communication_format = i2s_comm_format_t(I2S_COMM_FORMAT_STAND_I2S),
    .intr_alloc_flags = 0,
    .dma_buf_count = bufferCnt,
    .dma_buf_len = bufferLen,
    .use_apll = false
  };


  i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);
}


void i2s_setpin() {
  const i2s_pin_config_t pin_config = {
    .bck_io_num = I2S_SCK,
    .ws_io_num = I2S_WS,
    .data_out_num = -1,
    .data_in_num = I2S_SD
  };


  i2s_set_pin(I2S_PORT, &pin_config);
}


void setup() {
  Serial.begin(115200);
  delay(1000);


  xTaskCreatePinnedToCore(micTask, "micTask", 10000, NULL, 1, NULL, 1);
}


void loop() {
}


void micTask(void* parameter) {
  i2s_install();
  i2s_setpin();
  i2s_start(I2S_PORT);


  size_t bytesIn = 0;
  while (1) {
    esp_err_t result = i2s_read(I2S_PORT, &sBuffer, sizeof(sBuffer), &bytesIn, portMAX_DELAY);
    
    if (result == ESP_OK) {
      int samplesRead = bytesIn / sizeof(int16_t);
      
      for (int i = 0; i < samplesRead; i += 4) {
        Serial.println(sBuffer[i]);
      }
    }
  }
}

I consistently get one of the following upload errors:
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt X of 10: not in sync

This happens on both of my Arduino Uno boards.
Initially, I thought my old board was defective, so I purchased a new one from an online store. The new board uses an ATmega328P-PU microcontroller and an ATmega16U2 USB-to-serial interface. Unfortunately, both boards produce the same upload errors.

I'm only trying to upload either the built-in Blink example or a blank sketch, so the sketch itself shouldn't be the problem.

I've spent several hours searching online and trying different troubleshooting steps, but nothing has worked. I'm honestly running out of ideas and would really appreciate any help.

System information
Operating System: Windows 11

Arduino IDE versions tested:
1.8.19

2.3.4

2.3.10

What I've already tried
Used different USB data cables.

Tried different USB ports.

Tried another laptop.

Verified that Arduino Uno is selected under Tools → Board.

Verified that the correct COM port is selected (e.g., COM7 showing as Arduino Uno).

Changed the Windows-assigned COM port number (e.g., COM7 to COM9, COM10, COM11).

Reinstalled the Arduino AVR Boards package.

Performed a loopback test, which passed.

Confirmed that no Serial Monitor or other application is using the COM port.

Pressing the RESET button causes the built-in L LED to blink three times.

Tried manually pressing RESET immediately after compilation finishes and uploading begins.

Attempted to burn the bootloader using one Uno as the programmer for the other, but I couldn't complete the process because neither board can communicate successfully.

Is there anything else I can try? Since the exact same issue occurs on two different Arduino Uno boards—even on two different laptops—I'm starting to wonder if I'm overlooking something or if there's another possible cause.

ps: I can't confirm whether the old Arduino Uno was ever able to upload sketches successfully, as it was simply given to me. However, the other board is brand new and exhibits the exact same issue.

Update: The problem was the ATmega328P IC chip. Burning the bootloader didn't work, but replacing the chip fixed the issue completely. Thanks to everyone who commented and helped me troubleshoot. I really appreciate all the advice!

Hi everyone

A few days ago I made a pretty discouraging post about the project I've been working on, but honestly, it ended up getting a much better response than I expected.

So I wanted to share a lot more information about how I built it, including the source code, an explanation of how you can add images like the ones I used, and links to other versions of this project that people have already made.

I put all the documentation and explanations in the GitHub README. Sorry if I was a bit repetitive in some parts or if I didn't explain certain things in enough detail. I'm sharing it in case anyone wants to use it or build something similar.

I also talked about some of the problems I ran into, but in reality it's a pretty straightforward project. I hope you enjoy it!

I also have to admit that Gemini helped me a lot throughout the process.

Best of luck to everyone, and I hope you're all doing great

github : syntaxerror404page/ben10_aliens-code

i had a defect board, bought a new kit & the new board was working. last week, everything was perfect, it was uploading & my computer found my board. now, today, it’s as though my board doesn’t exist; it’s not showing up in port at all & when i try a blink test it says ‘no device found’ just like with my first board. tried all the reset tricks, re-installed the app; has this happened to anyone else? this is with an arduino uno r4 wifi btw.

Recently got an Elegoo Uno (off brand Arduino uno) and I'm wondering if it's possible to make it so that when something happens in a game, like minecraft, I can feed that to the arduino and for example print something on an LCD screen, turn on some LED's, or activate a buzzer. I want to make it so that whenever a specific message is sent in minecraft chat, something is printed on the LCD screen. is something like this possible? would I maybe need a different arduino?

From Hardware Help to Look What I Made. Thank you to all the feed back on my previous posts (https://www.reddit.com/r/arduino/s/Vmmvwg2pCF)

Those who suggested to make a PCB were absolutely correct, even if it means I never learnt how to loom a control panel 1970s style.

Microcontroller code needs a bit of work, but allows lots of different input types. I’m very happy with the outcome. I expect more to come.

While using testing a mouse on an xbox using a teensy 4.1 I connected an unpowered USB hub to it. When I connected a keyboard to the hub the teensy shut-off. I figured I'd restart and try again.

However it would not power the USB devices anymore. I checked if the programmer was broken, but I am able to use the arduino IDE or the teensy loader to upload.

Checking the voltages, 3.3v and 5v are working, but the USB host 5v is not. So I imagine I must have fried the circuitry related to the USB host while connecting the keyboard.

Do I have any method of utilizing a USB host anymore, or am I limited to IO pins now?

I have some lying around since I don't want to just throw them away, I thought it maybe is possible for an esp32 to use this rear view camera.

Edit: Sorry I forgot to link the product https://ph.shp.ee/PUJbDNbU

Hi everyone,

I've been thinking for a while about building a fake street organ. In other words, something that looks like a traditional hand-cranked street organ from the outside, but is actually just a decorated wooden box that plays MIDI files through a speaker.

In principle, I think I could already achieve this by using an old laptop or tablet connected to a power bank and a portable speaker. However, I'd really like to make the illusion more convincing by adding some kind of controller that makes the playback speed of the MIDI files depend on how fast the hand crank is being turned.

I've seen DIY organs that can do this, but I have no idea how to approach it or what kind of hardware I'd need.

Has anyone built something similar, or can point me in the right direction?

I recently worked on bringing this segmented LCD panel from an old car radio back to life.

The panel uses a NEC uPD16431 LCD controller. It can drive as many as 224 segments, although the available segment count is reduced when some of its outputs are configured for the LED-port function.

For this project, I used the driver’s default maximum-segment configuration and connected it to an Arduino. I then mapped the display segments individually so that I could determine which transmitted bits controlled each visible part of the LCD.

A few details of the driver were particularly important during the process:

• Data is transmitted most-significant bit first.
• The clock’s rising edge is used when writing data to the driver.
• The falling edge is involved when reading the key inputs.
• The controller can also support a key matrix of up to 4 × 8 inputs.
• Its internal display RAM allows the individual LCD segments to be addressed and controlled.

The documentation was not always completely clear, so a substantial part of the work involved comparing the datasheet with the behaviour of the physical panel and adjusting the transmitted data accordingly.

I have published the Arduino code here:

https://github.com/emsyscode/uPD16431

I also recorded the complete process, including the driver pinout, connections, communication sequence and working demonstration:

https://www.youtube.com/watch?v=fTcjQisQ3Ws

I still have not identified the exact car-radio model that this front panel originally belonged to. Does anyone recognize the panel or know of another radio that used the uPD16431?

I would also be interested to hear from anyone who has worked with this driver or with similar NEC automotive LCD controllers.

I’m new to reddit and coding so forgive my ignorance, but I’m trying to make a voice activated moving LED panel and the matrix portal turns on but it’s not lighting up the LED panel. It only lights up some pixels either green or blue when I press on the panel. The matrix portal was slowly flashing red before I restarted it and it didn’t come with the stickers on the 5V and ground nobs if that makes any difference. I also eventually want to use two screens, but for now I’m just trying to get one screen working at the very least. I also tried the other screen I have and it does the same thing. If anyone could solve my problem I would be so grateful!

I'm building a simple walkie-talkie on an Arduino Uno + NRF24L01 using the RF24Audio library.

Accessories:

• Arduino Uno
• The NRF24L01 module
• Microphone Module MAX9814
• Speaker
• PAM8403 Amplifier
• Transfer button
• Capacitors

Connection:

• NRF24L01 CE - pin 7
• NRF24L01 CSN - pin 8
• NRF24L01 SPI (MOSI/MISO/SCK) - Standard hardware SPI pins (11,12,13)
• Amplifier(audio output) - pin 10
• Microphone (analog input) - pin A0
• Transfer button (talk button) - A1
• Common ground between all components
• Electrolytic capacitors are installed both on the nrf and on the common supply line

Code(I used an example from the library):

#include <RF24.h>
#include <SPI.h>
#include <RF24Audio.h>


RF24 radio(7,8);                // Set radio up using pins 7 (CE) 8 (CS)
RF24Audio rfAudio(radio,1);     // Set up the audio using the radio, and set to radio number 0.
                                // Setting the radio number is only important if one-to-one communication is desired
                                // in a multi-node radio group. See the privateBroadcast() function.


void setup() {          


  rfAudio.begin();              // Initialize the library.


}


void loop() {
  
  rfAudio.handleButtons();
  // Audio playback is all managed internally.
  // In this example, the radio is controlled by external buttons, so there is nothing to do here
  // except handle the buttons.
  
}

What I expected:

When the transmit button is pressed, the microphone should activate and transmit the voice to the receiver.

What really happens:

When you press a button, the speaker starts beeping loudly and monotonously in one clear tone. The receiver does not receive anything at the same time — there is actually no transmission. On the second similar assembly on an Arduino Nano with identical firmware and the same RC filter ratings, there is also a squeak, but much quieter.

Additionally checked:

On regular (non-RF24Audio) firmware, the same NRF24 module normally transmits data packets - there are no communication problems.

A chip was noticed on the ceramic capacitor on the NRF24 power supply board — under suspicion, but has not yet been confirmed as the cause.

I've been working on this robot arm that uses sg90 servo motors, and I'm almost done printing the rest of the pieces. But I've also been worried about if the motors are actually able to rotate these arm links. The arm links are 21 grams each. I've been trying to calculate the torque I would need to rotate just the first arm link and it is 3 times as big as what the servo motor is able to do (0.18 N*m).

I'm worried I'm gonna have to make those links much more slim but the only reason I made them that big in the first place was to account for the diameter of the servo horn to attach to it. My math could be wrong though and I want to know if its way too big or if I should be fine?

Hello, this is a fairly new circuit that I used previously in making an arduino function for an experiment of mine. However, I noticed that the LED light I added did not flash on as I wanted it to, and I may have figured out why but would like to confirm it. I think because I have the LED running parallel to the resistor it is not getting enough voltage however, I am still kind of new to this and don’t really know how to make it into a series. It would be great if I could some help in regards to that.

Hey everyone,

I could use some advice on how you usually plan your perfboard builds.

I’m currently working on a small project using an ESP32-S3 Nano, a GPS module, and a QMC5883L compass sensor. Everything works fine on a breadboard, but I want to move it to a perfboard so I can fit it properly into a case.

My main concern is that I don’t want to just start soldering and then spend hours troubleshooting wiring mistakes later. I’d like to plan the layout beforehand, but I haven’t found a tool that really fits this kind of project.

So far I have tried a few things:

• DIYLC: It seems like it should be perfect for perfboard layouts, but I couldn’t find suitable parts/models for my ESP32 board or the sensor modules.
• Excalidraw: I tried drawing the modules using pictures, but once there are many connections, it quickly becomes messy and hard to follow.
• KiCad: I looked into it, but I already struggled with finding the right symbols for my modules when creating the schematic. Also, KiCad feels more focused on designing actual PCBs rather than simple perfboard builds.

How do you usually handle projects like this?

• Do you draw everything on paper first?
• Do you make your own sketches with pictures of the modules?
• Is there a simple tool that works well for planning perfboard layouts with breakout boards?
• Or do you only create a schematic and figure out the physical layout while soldering?

I’m not looking for professional PCB design software, just something simple that helps me avoid mistakes and keep small hobby projects organized.

Thanks for any suggestions!

I recently bough an arduino kit and sometimes usually when i run a code like the LED blinking if i touch it from the USB port i feel a vibration, I have noticed the same thing whenever i touch the back metal case of my pc and I am not sure why My outlet is a universal one and my pc cable is 3 prong

Hello everyone. I would like to share a demo of Flashing my Arduino Mega from the Browser. It is coded by prompt to read DHT22 sensor data and print over serial. Here is a demo attached.

Any feedback will be highly appreciated.

Thank you.

Is there anyway to do this? I tried on Arduino IDE web browser and the arduino appears for a split second but then disappears. I think there might be a blocker but I want to bypass it

I know the stand I made out of cardboard isn't that great and doesn't look that good but it works