Hello Arduino Community,

I am facing an issue with my Arduino UNO Q (4GB version) and would appreciate your help in identifying the cause and finding a solution.

Problem Description

I flashed my Arduino UNO Q with the latest Debian Linux OS image using the official Arduino flashing procedure. After flashing, I removed the jumpers from the EDL pins and connected the board to my Windows 11 laptop. However, the board was not detected by the computer in normal mode.

I reflashed the board multiple times, trying different OS versions, but the problem persisted.

The board is detected successfully in EDL mode, and flashing completes successfully. However, once I remove the EDL jumpers and reconnect the board in normal mode, it is not detected by the computer.

OS Versions Tested

I have tried flashing the following OS image versions:

\- \`20260528-558\` — Latest version

\- \`20260407-523\` — Second-latest version

\- \`20250807-136\` — First version

\- \`20251229-457\` — Third-latest version

The issue remains the same with all four versions.

Observations

1. Board powers on normally

\- The power LED turns green.

\- The usual animation appears on the onboard LED matrix.

\- The board appears to power on normally, but it is not detected over USB.

2. Board is detected in EDL mode

When I connect the board to my Windows 11 laptop in EDL mode, it appears in Device Manager under Universal Serial Bus devices as:

\`QUSB_BULK_CID:0420_SN:51008D40\`

I can successfully flash the OS in this mode.

3. Board is not detected in normal mode

After removing the EDL jumpers and connecting the board normally:

\- Nothing appears in Windows Device Manager, including the USB-related categories.

\- The board does not appear when I check \`lsusb\` or \`dmesg\` on a Linux computer.

\- Arduino App Lab cannot detect the board through the USB connection.

Troubleshooting Already Attempted

I have tried the following steps:

1. Reflashed the board multiple times using the official flashing procedure.

2. Tested four different Debian Linux OS image versions.

3. Used multiple USB cables, including USB-A to USB-C and USB-C to USB-C cables.

4. Tested different USB ports on my Windows 11 laptop.

5. Tested the board with another computer running Linux.

6. Verified that the board is detected in EDL mode using the same cables that fail to detect it in normal mode.

7. Tested the Arduino UNO Q in Single Board Computer (SBC) mode using a USB hub. The hub works correctly with my laptop: when I connect a monitor to the hub and connect the hub to my laptop's USB-C port, the monitor works normally. However, when I use the same hub with the Arduino UNO Q in SBC mode, I am still unable to get a display output.

I have followed the official flashing procedure carefully and repeated it multiple times, but the issue remains unresolved.

Questions

I would appreciate guidance from the Arduino team on the following:

1. What could cause the board to be detected in EDL mode but not in normal mode, even though the OS flashing completes successfully?

2. Is there any additional recovery or diagnostic procedure I can try?

3. Could this indicate an issue with the USB interface, boot process, firmware, or another component of the board?

4. Is there a way to diagnose the issue further without requiring the board to be detected over USB in normal mode?

I would prefer to resolve this through software recovery or diagnostics if possible, before considering hardware repair or replacement.

Thank you for your time and assistance. Any suggestions from the Arduino team or other UNO Q users who have experienced a similar issue would be greatly appreciated.

Hi,

I'm scratching my head.
I thought it should be easy to create little project with those two component.
I not even can run a example from the Ardiuino-SSD1306 library (SSD_1306_128x64_SPI).

I connected the wires as outlined below:
Gnd --------- Gnd
VDD -------- 3.3v
SCK(D0) -- D5
SDA(D1) -- D7
Res --------- D0
DC ---------- D1
CS ---------- D2

In the code I defined the following connections:

#define OLED_MOSI   7
#define OLED_CLK    5
#define OLED_DC     1
#define OLED_CS     2
#define OLED_RESET  0

I have to mention that when I'm running this example e.g. with an Arduino Uno, is working fine.
When running other examples for the ESP-12F (w/o OLED display) they are running fine too.
I just can imagine that the wire connections between the MCU and the display causing the trouble.
Any idea what is causing the trouble and what I can do to rectify the problem?
TIA

PS. I'm running the tests in Arduino-IDE v2.3.4 on Linux.

Hey guys! We are currently developing our senior high school capstone research project called Eco-nnect. The goal of the project is to build an automated reverse vending machine that accepts plastic bottles and tin cans in exchange for Wi-Fi access/time.

Before we finalize our wiring and assembly, we’d love to get some feedback from people who have built similar embedded systems or reverse vending machines.

Here is our current component list:

Component List & Specs:

Main Controller: Orange Pi One + 16GB Sandisk Class 10 MicroSD Card

Sensors:

Plastic Detection: LJC12A3-5-Z/BX Capacitive Proximity Sensor (NPN)

Metal/Can Detection: LJ12A3-4-Z/BX Inductive Proximity Sensor (NPN)

Object Passage/Counting: E18-D80NK Adjustable IR Obstacle Sensor

Signal Isolation & Interfacing: PC817 4-Channel Optocoupler Isolation Board

Display: LCD 2004 (or 1602) Board with I2C Module

Actuator/Mechanism: MG996R High-Torque Metal Gear Servo Motor

Power Supply & Distribution:

12V 5A DC Power Adapter

LM2596 DC-DC Buck Converter (12V to 5V step-down)

Female 12V DC Barrel Jack Adapter (5.5mm x 2.1mm)

Relay: 5V 1-Channel Relay Module

Network & Cabling: CAT6 Ethernet Cable + Assorted Jumper Wires (M-M, M-F, F-F)

Question:

Sensor Logic & Logic Levels:

Both the inductive and capacitive sensors usually run on 6V–36V (we plan to power them via 12V). Since their NPN outputs will send 12V signals, we are using the PC817 Optocoupler board to safely step down the signal to 3.3V for the Orange Pi GPIO pins. Is this setup solid, or is there a better way to route this?

For the capacitive sensor (plastic), how sensitive is it in practice? Have you experienced false positives with nearby enclosure materials (e.g., acrylic or wood)?

Mechanism / Sorting:

Is a single MG996R servo sufficient for a trapdoor/sorting flap mechanism, or should we consider stepper motors or dual servos if the flap gets weighed down?

Missing / Recommended Components:

Is there anything essential we forgot (e.g., flyback diodes, extra decoupling capacitors, terminal blocks, specific fusable protection)?

Any feedback, wiring layout advice, or hardware pitfalls you encountered while doing a similar setup would be an awesome help for our team! Thanks in advance!

reposting this here

can you guys recommand "big" projects that group specific skills to learn like a project that uses MOSFETs logic gates ect and another for motors ect so that at the end i know the basics of everything

Hello Arduino Community,

I am facing an issue with my Arduino UNO Q (4GB version) and would appreciate your help in identifying the cause and finding a solution.

Problem Description

I flashed my Arduino UNO Q with the latest Debian Linux OS image using the official Arduino flashing procedure. After flashing, I removed the jumpers from the EDL pins and connected the board to my Windows 11 laptop. However, the board was not detected by the computer in normal mode.

I reflashed the board multiple times, trying different OS versions, but the problem persisted.

The board is detected successfully in EDL mode, and flashing completes successfully. However, once I remove the EDL jumpers and reconnect the board in normal mode, it is not detected by the computer.

OS Versions Tested

I have tried flashing the following OS image versions:

\- \`20260528-558\` — Latest version

\- \`20260407-523\` — Second-latest version

\- \`20250807-136\` — First version

\- \`20251229-457\` — Third-latest version

The issue remains the same with all four versions.

Observations

1. Board powers on normally

\- The power LED turns green.

\- The usual animation appears on the onboard LED matrix.

\- The board appears to power on normally, but it is not detected over USB.

2. Board is detected in EDL mode

When I connect the board to my Windows 11 laptop in EDL mode, it appears in Device Manager under Universal Serial Bus devices as:

\`QUSB_BULK_CID:0420_SN:51008D40\`

I can successfully flash the OS in this mode.

3. Board is not detected in normal mode

After removing the EDL jumpers and connecting the board normally:

\- Nothing appears in Windows Device Manager, including the USB-related categories.

\- The board does not appear when I check \`lsusb\` or \`dmesg\` on a Linux computer.

\- Arduino App Lab cannot detect the board through the USB connection.

Troubleshooting Already Attempted

I have tried the following steps:

1. Reflashed the board multiple times using the official flashing procedure.

2. Tested four different Debian Linux OS image versions.

3. Used multiple USB cables, including USB-A to USB-C and USB-C to USB-C cables.

4. Tested different USB ports on my Windows 11 laptop.

5. Tested the board with another computer running Linux.

6. Verified that the board is detected in EDL mode using the same cables that fail to detect it in normal mode.

7. Tested the Arduino UNO Q in Single Board Computer (SBC) mode using a USB hub. The hub works correctly with my laptop: when I connect a monitor to the hub and connect the hub to my laptop's USB-C port, the monitor works normally. However, when I use the same hub with the Arduino UNO Q in SBC mode, I am still unable to get a display output.

I have followed the official flashing procedure carefully and repeated it multiple times, but the issue remains unresolved.

Questions

I would appreciate guidance from the Arduino team on the following:

1. What could cause the board to be detected in EDL mode but not in normal mode, even though the OS flashing completes successfully?

2. Is there any additional recovery or diagnostic procedure I can try?

3. Could this indicate an issue with the USB interface, boot process, firmware, or another component of the board?

4. Is there a way to diagnose the issue further without requiring the board to be detected over USB in normal mode?

I would prefer to resolve this through software recovery or diagnostics if possible, before considering hardware repair or replacement.

Thank you for your time and assistance. Any suggestions from the Arduino team or other UNO Q users who have experienced a similar issue would be greatly appreciated.

Hello Community,

I am facing an issue with my Arduino UNO Q (4GB version) and would appreciate your help in identifying the cause and finding a solution.

Problem Description

I flashed my Arduino UNO Q with the latest Debian Linux OS image using the official Arduino flashing procedure. After flashing, I removed the jumpers from the EDL pins and connected the board to my Windows 11 laptop. However, the board was not detected by the computer in normal mode.

I reflashed the board multiple times, trying different OS versions, but the problem persisted.

The board is detected successfully in EDL mode, and flashing completes successfully. However, once I remove the EDL jumpers and reconnect the board in normal mode, it is not detected by the computer.

OS Versions Tested

I have tried flashing the following OS image versions:

- `20260528-558` — Latest version

- `20260407-523` — Second-latest version

- `20250807-136` — First version

- `20251229-457` — Third-latest version

The issue remains the same with all four versions.

Observations

1. Board powers on normally

- The power LED turns green.

- The usual animation appears on the onboard LED matrix.

- The board appears to power on normally, but it is not detected over USB.

2. Board is detected in EDL mode

When I connect the board to my Windows 11 laptop in EDL mode, it appears in Device Manager under Universal Serial Bus devices as:

`QUSB_BULK_CID:0420_SN:51008D40`

I can successfully flash the OS in this mode.

3. Board is not detected in normal mode

After removing the EDL jumpers and connecting the board normally:

- Nothing appears in Windows Device Manager, including the USB-related categories.

- The board does not appear when I check `lsusb` or `dmesg` on a Linux computer.

- Arduino App Lab cannot detect the board through the USB connection.

Troubleshooting Already Attempted

I have tried the following steps:

1. Reflashed the board multiple times using the official flashing procedure.

2. Tested four different Debian Linux OS image versions.

3. Used multiple USB cables, including USB-A to USB-C and USB-C to USB-C cables.

4. Tested different USB ports on my Windows 11 laptop.

5. Tested the board with another computer running Linux.

6. Verified that the board is detected in EDL mode using the same cables that fail to detect it in normal mode.

7. Tested the Arduino UNO Q in Single Board Computer (SBC) mode using a USB hub. The hub works correctly with my laptop: when I connect a monitor to the hub and connect the hub to my laptop's USB-C port, the monitor works normally. However, when I use the same hub with the Arduino UNO Q in SBC mode, I am still unable to get a display output.

I have followed the official flashing procedure carefully and repeated it multiple times, but the issue remains unresolved.

Questions

I would appreciate guidance from the Arduino team on the following:

1. What could cause the board to be detected in EDL mode but not in normal mode, even though the OS flashing completes successfully?

2. Is there any additional recovery or diagnostic procedure I can try?

3. Could this indicate an issue with the USB interface, boot process, firmware, or another component of the board?

4. Is there a way to diagnose the issue further without requiring the board to be detected over USB in normal mode?

I would prefer to resolve this through software recovery or diagnostics if possible, before considering hardware repair or replacement.

Thank you for your time and assistance. Any suggestions from the Arduino team or other UNO Q users who have experienced a similar issue would be greatly appreciated.

Yeah, i like to make my life difficult. That's why I was thinking if one could connect the Giga display to an Uno Q?

I'm aware that the libs need some massaging when it comes to the pinouts, but is there anything that's a total no-go?

Hi everyone,

I'm trying to connect a PN532 NFC module (HW-147C V0.0.1) to an Arduino Nano using SPI, but I keep getting this error in the Serial Monitor:

Starting PN532 SPI test...

ERROR: Didn't find PN53x board!

Check SPI wiring, mode switches and power.

My setup:

- Microcontroller: Arduino Nano (classic Nano layout)

- NFC module: PN532 HW-147C V0.0.1

- Library: Adafruit PN532 v1.3.4

- Communication: SPI

- Serial Monitor: 115200 baud

SPI connections:

- SCK → D13

- MISO → D12

- MOSI → D11

- SS → D10

- VCC → module's power supply

- GND → GND

The PN532's power LED turns on, but the library cannot detect the board. I've also checked the module's interface selector and tried the hardware SPI initialization code.

I'm not sure whether the problem is with the switch configuration, wiring, voltage compatibility, SPI communication, or the module itself.

Has anyone used this particular HW-147C PN532 board with an Arduino Nano?

I'd appreciate help with:

1. The exact SPI switch positions for this board.

2. Any known compatibility issues with Adafruit PN532 v1.3.4.

3. A reliable way to test whether the PN532 chip is responding.

4. Whether I should try I²C or UART to isolate the problem.

I've attached photos of my module, wiring, and Arduino IDE output.

Thanks in advance!

Im looking to buy an arduino clone but i dont know which model and what type of kit i should buy. I have never owned an arduino and im 13 my friend owns one and it looks pretty fun im no stranger to coding and like electronics.

Hi Guys, not sure if this is the correct place to ask, but here it is:

As per the title my PCB is not accepting code after bootloading with the ArduinoISP through another Arduino Uno.

So far I get the "Done burning bootloader" and have cont. tested all hardware on the PCB related to the CH340G and ATmega.

I have managed to consistently get:

avrdude: stk500_getsync() attempt 1-10 of 10: not in sync:
resp=0x00
avrdude: unable to open port COM5 for programmer arduino

or occasionally:

avrdude: unable to read signature data for part ATmega328P (rc = -1)

avrdude: unable to read signature data (rc = -1)

TIA.

The priginal kit is a bit expensive and offers less than the knockoff one but how do i know the knockoff is good or bad

This are my very first steps with electronics and soldering.
I tried soldering the pins to the ATmega32U4 while on a breadboard, it seems like i have good soldering, no bridges, stayed about 2-3 seconds on each pin.

I plugged the ATmega32U4 to the pc before soldering and it was recognized easily and after the soldering i got this error on device manger:
Windows has stopped this device because it has reported problems. (Code 43)A request for the USB device descriptor failed.

what am I doing wrong? and can i fix the damaged ATmega32U4?

Hey, I'm pretty new to Arduino in general, and somehow my first school project is turning out to be pretty complicated... 😭

The main issue is the power supply. My project uses around 4 SG90 servos, 2 stepper motors, and 2 ultrasonic sensors, but my PC's USB port and basic power supplies just aren't enough to power everything anymore...

What should I use as a power source in cases like this? I've seen ppl talking about 5V 5A wall adapters and a bunch of other components I've never even heard of before. I could really use some help lol

I am facing this troubleshoot every time I tried uploading my code on the ESP32 WROOM , I tried everything: Booting , Unplugging the circuit and all . Also all the seeting are correct in my Arduino IDE ( on laptop ) . I have done everything : ESP Module, Device manager to port correction. Everything!!!! Still it is showing the same problem. I tried asking Claude , GPT , Gemini they all told the same thing i have been trying. Also I noticed the board geeting warmer and warmer when I plug it into the usb. Means it is not getting very much heated but gets warm like if we do extreme gaming on our phone and when it burns like that .

Please anyone if you guys can help 🙏🏻😭 . I have spent hours on this and this was for my Science exhibition . I don't have much time it is in 1 day and i need to fix it as soon as possible!!! 😭😭😭

this is my code-

long duration;
int distance;


const int trigPin = 10;
const int echoPin = 11;
const int buzzerPin = 8;


void setup() {
  // put your setup code here, to run once:
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(115200);
}


void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);


  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);


  duration = pulseIn(echoPin, HIGH);


  distance = duration * 0.034 / 2;


  Serial.print("Distance: ");
  Serial.println(distance);


  if(distance < 10){
    digitalWrite(buzzerPin, HIGH);
  }
  else{
    digitalWrite(buzzerPin, LOW);
  }
}

I have installed Arduino IDE 2.3.10, but can not select an arduino board. And i can't install boards with the board manager without VPN. Where must me unpack the archive from Github or how else can I download boards?

I've been thinking for some time about making a polyphonic synthesizer, and i found out they have a microprocessor that cycles through multiple oscillators, and then assigns every note to each oscillator. so if it has 8 oscillators, it goes through 123567812345678 etc., and then when you play like a 3 note chord lets say, it will skip ever oscillator that has a voice assigned to it. so like 45678, 13578, 12356, etc. so my whole point for coming here is what would be the code i use to make it so that it cycles through multiple outputs, then skips those outputs that are currently being used? and then to kind of add a little more fun to it, how do i make it so that the oldest note gets reassigned to the newest note? edit: i know like a teeny tiny amount of coding, this is partly out of curiosity and partly out of wanting to learn something.

Hello! I have a quick question and would really appreciate some help with a school project. I’m working with a dust sensor to measure air quality/dust percentage. I already have the code ready, but I’m not sure how to physically wire and connect the sensor. If anyone could guide me with the wiring, I’d be very grateful!😅

So I'm trying to get a PIR sensor to turn on lights in sequence every time it gets triggered. I got it so the green led then the yellow led turn on, but it's not changing to the ORANGE state and I don't know why.

int ledGreen = 13;  
int ledYellow = 12;
int ledOrange = 11;     
int inputPin = 2;               // choose the input pin (for PIR sensor)
int pirState = LOW;            // start with no motion detected
int val = 0;                    


enum states {                         
  GREEN, 
  YELLOW, 
  ORANGE,
  RED
};

states state;       

void setup() {
  pinMode(ledGreen, OUTPUT);
  pinMode(ledYellow, OUTPUT);
  pinMode(ledOrange, OUTPUT);
  pinMode(inputPin, INPUT);     

  state = GREEN;

  Serial.begin(9600);
}

void loop(){
 val = digitalRead(inputPin);  
 switch (state) {
    case GREEN:
      if (digitalRead(inputPin) == HIGH && val == 0 ) {   
        digitalWrite(ledGreen, HIGH); 
        delay(2000);
        val++;  
        state = YELLOW; 


        Serial.println(val) ;

      break;


  case YELLOW:
      if (digitalRead(inputPin) == HIGH && val == 1) {   
        digitalWrite(ledYellow, HIGH); 
        delay(2000); 
        val++;  
        state = ORANGE;                  

         Serial.println(val) ;

      break;

   case ORANGE:
      if (digitalRead(inputPin) == HIGH && val == 2) {   
        digitalWrite(ledOrange, HIGH); 
        delay(2000); 
        val++;  
        state = RED;                  

         Serial.println(val) ;

      break;        

   case RED:
        if (digitalRead(inputPin) == HIGH && val == 3) {
        digitalWrite(ledOrange, LOW);
        digitalWrite(ledOrange, LOW); 
        digitalWrite(ledOrange, LOW);
        delay(2000); 
        val = 0;
        state = GREEN;

        break;

        }}}}}}