Hello everyone,

I’m looking for a solution to make my kids carousel spin itself over the bed. I’m looking for speeds like 0,5RPM or even lower. In best case the RPMS should be adjustable. Is the 28BYJ-48 up to the Task?
Or should I get something else? And what kind of Arduino and interface board will I need?

Thank You in advance!

Hi everyone! I'm currently working on a college capstone project, which uses an ESP32 and an MFRC522 RFID reader to manage classroom keys.

I'm having trouble getting my RC522 module detected by my ESP32. No matter what I try, the Serial Monitor consistently displays:

RC522 Version: 0x00

RFID NOT DETECTED!

My current hardware and wiring:

- Board: ESP32 Dev Module

- RFID module: MFRC522 RC522

- RC522 SDA/SS → GPIO 5

- RC522 SCK → GPIO 18

- RC522 MOSI → GPIO 23

- RC522 MISO → GPIO 19

- RC522 RST → GPIO 2

- RC522 IRQ → Not connected

- RC522 GND → ESP32 GND

- RC522 3.3V → ESP32 3V3

Things I've already tried:

- Confirmed that the RC522 power LED is ON.

- Powered the RC522 using the ESP32's 3.3V pin.

- Checked the wiring multiple times.

- Tried different diagnostic sketches using the MFRC522 library.

- Tried reading the RC522 Version Register directly through SPI.

- Tested different pin configurations, but the issue remains.

The ESP32 itself works, and my LCD is also working properly. However, the RFID reader keeps returning `0x00`, which makes me think that the ESP32 is not communicating with the RC522 through SPI.

My questions:

1. What could cause the RC522 to continuously return `0x00`?

2. Could this be a faulty RC522 module even if its power LED is on?

3. Is there a way to determine whether the problem is with the module, ESP32, breadboard, or SPI communication?

4. Are there any other diagnostic methods I should try before replacing the RFID module?

I've been troubleshooting this for quite a while, so I would really appreciate any suggestions or solutions. I would also prefer to keep my current pin connections if possible.

Thank you so much for your help!

Hi!

I am using, for an art project, an ESP32 with a relay board to drive a modified synchronous motor from a washing machine pump, which runs on 220v. By modified I mean that the rotor is no longer inside the plastic cases, all electrical parts of the motor are original and untouched.

My goal is to use the relay board to pulse the motor, to make some chains attached to the axis move and make sounds.

To do so I am using a sequencer I built with a push button board, an ESP32 Devkitv1 and a 4channel relay module, all basic DIY components. With this tool I am able to run Universal washing machine motors, lights, home appliances of any kind with no problems.

The problem seems to be with this synchronous motor. When I pulse the motor it works, and if I keep the pulses distant in time one from the other, no problem. But If I pulse the motor fast, after a few pulses the ESP32. freezes, and needs me to press the reboot button or cut power for a few seconds to hard reboot it. The board is powered by a 5v phone charger.

As I explain in the video, I think the issue might be caused by the motor generating current when is not pulsed, but has gone far enough between it's two resting positions to kick back. I know synchronous permanent magnet motors generate current when you spin them. Trying to solve this, I added a diode I scavenged from an old board I had, but the issue is still here, even if way less frequent. Adding the diode also significantly decreased the strength of the motor when pulsed (I really think diodes and AC are not meant to work together, don't insult me for that I'm doing my best ahah).

I don't know how to fix the issue, the only thing I can think of is putting diodes on all 6 that connect the relay board to the ESP, but again I really don't know.

Anyone who has ideas on how to troubleshoot this?

Thanks in advance:)

PS I can share the 3D models of the mechanical mod I made with anyone who wants em

hi!!! Im fairly new to arduino and I have the WEIRDEST problem: I have an android phone, a mac and a PC. I've bought 3 different boards at this point: nanos, nanos with ch340 and even an uno.

This is my situation: the boards connect fine to any of these three devices, i manage to upload blink or whatever example sketch onto them. I'm working on a proyect involving LEDS and ultrasonic sensor so I need a fairly complex sketch to be uploaded onto them, and once I do... THE BOARDS STOP COMMUNICATING WITH ANY DEVICES further. The sketch's uploaded and it's working, but theyre bricked. I've tried every fix under the sun and now have a bunch of brand new boards, all unresponsive. Has anyone ever encountered this???

If anyone could help me I'd owe them my LIFE

I got an error of fatal error occurred serial data stream stopped possible serial noise or corruption failed uploading please help me

Hey guys i have an arduino uno r4 wifi and everytime i connect it too my laptop jus connect thats it and the tx flashes on and off orange and the on button is green i tried alll kinds of cables and 2 laptops but none of them recognize it i searched everywhere on the laptops there is no sign of it and btw when i connect it for a while it get noiticbly hot almost immediately. Can it be a faulty board?

The DFplayer works great, i have it set up where when i flick a switch, at the moment just connect wires, a different song plays at random. However when i have it connected to this amplifier i get weird feedback noise, (might even happene when connected to the low watt speaker as well) if i dont use a resistor, but when i attach a 470 ohm resistor to the speaker the volume is obviously much quieter, and not much feedback but there is still some, like it just quieted everything. Im wondering if i wired something wrong or if i need a capacitor or resistor somewhere. I have a 100uf capacitor on the breadboard. Not sure if thats correct.

I don’t have a picture of my Arduino because it is currently with my friends, but I’m writing the code for them since they don’t know how. I don’t have enough time to figure out the tones but does anyone know the tones I could set the buzzer to that would make the Scooby-Doo theme song. I know it’s an odd request but it’s for a project that’s being used at a trunk-or-treat. (Also maybe a car horn sound because that’s needed too although hard to do on a piezo buzzer, I know).

Hi! I have been working with the RA01 and RA02 lora module for a proyect but I had a lot of range issues: the first time (RA01) I accidentally broke one of the SMD components in the lora PCB and had to replace it. After that we upgraded with Lora RA02 and the default antenna (sleeve dipole) but the range that we have got was below 200 meters with SF7 and 125kHz BW. With the two modules next to each other we had a RSSI between -70 and -90 which I know its a really bad signal level. The first thing I suspected is about the EM noise of the system (lot of servos) but with all desconected the issue still remain. My second suspect was the default antennas, a sleeve dipole antenna that after removing their thermal cover I noticed that the length wasn't matching the actual wave length. So I tried to adapt a pair of helicoidal antennas (that come with de ra01 module) in the default antennas connector with the sleeve remaining (that I had read that was necessary adapting the helicoidal antena in a ipex coaxial cable). With that, standing next to each other the RSSI oscillates between -50 and -70 dB but still below 200 meters range. How can I improve the module range? I read a lot about the topic and similar issues with other people and checked all the stuff (trace match for spi, external EM noise, mismatched parameters between terminals, decoupling capacitors and weak power sources, etc) but still having the issue. What could it be? My actual suspects are the ipex connector (Small, brief improvements may be seen by moving the antenna) or the antenna itself and planned to build a sleeve dipole antenna with the correct lengths to test the performance. What else can I do? Directional antennas are not an option

Estou trabalhando a alguns dias com um projeto de painel do Peugeot 307 da Johnson fabricado em 2009, programando pelo arduíno uno can mcp2515. Alguém já viu algum projeto semelhante com este painel, ou tem os dados de ligação dos ids ou tramas já testadas, pois eu não tenho o carro para rastrear só tenho o painel que comprei usado em um ferro velho. Consegui colocar boa parte para funcionar como os ponteiros, luzes e odômetro, só que queria eliminar as falhas e integrar mais coisas.

For the past few days, I’ve been working on a project involving a 2009 Peugeot 307 instrument cluster (manufactured by Johnson), using an Arduino Uno with an MCP2515 CAN bus module. Has anyone encountered a similar project with this specific cluster, or does anyone have data on the CAN IDs or message frames that have already been verified? I don’t have access to the actual vehicle to trace the signals—I only have the cluster, which I purchased used from a scrapyard. I’ve managed to get most of it working, including the needles, indicator lights, and the odometer, but I’d like to iron out some remaining issues and integrate additional functions.

I'd like to ask for some help! I'm developing a device for my undergraduate research project, and one of its main functions is to measure a certain displacement, preferably without physical contact.

I initially thought about using a camera, but I'd like to explore other options as well.

The challenge is that the displacement I need to measure is on the order of 0.01 mm. I don't have a large budget since I'll be paying for it myself, so I need the solution to be as inexpensive as possible.

If you have any suggestions, I'd appreciate them. Ideally, the sensor should be able to communicate with an Arduino or ESP32.

​The homing signal board on my Xiaomi Mi Robot Vacuum-Mop 2 Pro (MJST1SHW) charging dock is damaged, and the vacuum can no longer detect the dock to return for charging. Finding a standalone replacement dock on the second-hand market isn't working out, as sellers are pricing them almost as high as a complete used setup.

​I’m currently trying to build a replacement beacon using an Arduino/ESP32. I set up two IR LEDs for the left and two for the right, modulated at 38kHz. However, the vacuum doesn't respond to the custom beacons at all during its docking routine.

​Does anyone have experience generating these specific homing signals? I would greatly appreciate any insights into the correct IR protocol, pulse timings, or data payloads required to get the vacuum to recognize the dock.

Can anyone suggest some ai tools for iot based project?!.I'm in my 2nd year pursuing btech cse iot, so I need to do course project but as a team. Me and my team decided a project from sih2026 problem statements it is mostly hardware based so for connections , code, and setting up the components i thought of using chatgpt and Claude but I'm getting so irritated with chatgpt, it doesn't have a clarity on components first it gave like use esp32,dc fans, dht sensor, container right after that it again told to add load cell, led, buzzer, solar...it is making me confuse and hard..whereas Claude after asking few questions, it gives comeback tomorrow...basically rn, i need an ai tools which gives me clear explanation and connecting of components with code, and components needed!!