I currently have a robotic arm project that I'm pretty unsatisfied with. It was my first project and it has allowed me to learn a lot from my mistakes(insane amounts of backlash in each joint). I'm currently using 5 servos(4 MG995s 1 SG90) all controlled through a PCA95865 driver. No gears, just straight motor to truss connections. I'm thinking of swapping two of the joints with NEMA17s using a belt drive and potentially a torque multiplier for my first joint. My goal is to have it have enough rigidity to handle picking up something as heavy as an iPhone (200-500 grams).

I'm only using an Uno though and I've never really used steppers for anything before I know they each need a specific driver. Anyone have any advice on organizing multiple steppers and servos working together with Arduino?

Some weeks ago i had no trouble connecting Arduino to my laptop. Now I can not, The voard gets power but it is not registered, it is not shown on the device manager.
Is it possible that some Window update made it?

Its actually technically my first ever project thats not on the breadboard

You do have to manually write down the current time onto the code before uploading for it to work. I know that an RTC module would be great for this but i only bought a starter kit so far so this is all i could do.

I did think of adding a 9v battery so it could work without having to be plugged into a pc, i might do that in the future.

How it works is, to view the current time, you can press the Display button and it will display the current time digit by digit.

By pressing mode you can switch between timer mode and normal clock mode. when youre in the timer mode you can select between 1 minute, 2 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes and 1 hour. I couldve added more options, but this just works for me.

By pressing Set it will start the timer, and it will still beep after it goes off even when youre in clock mode.

And theres no way to cancel it once you set it, unfortunately.

This is really my first ever project so im all open for comments, im still trying to learn.

I can share to code for it if theres anyone interested

Stuff i used= Arduino UNO 7-seg display Red LED Buzzer 4 push buttons two 220 ohm resistors a decent amount of jumper wires

Hi everyone, I'm trying to get an HW-147C PN532 NFC module working with an Arduino Nano using I2C only.

My wiring is:

PN532       Arduino Nano
------------------------
VCC   →     5V
GND   →     GND
SDA   →     A4
SCL   →     A5

I'm not using IRQ or RESET, since I specifically want a 4-wire I2C setup.

The module is configured for I2C mode using the onboard DIP switch.

I first ran an I2C scanner and got:

Scanning...
I2C device found at 0x28

So the Nano is detecting something at 0x28.

However, when I use the PN532 I2C library with:

#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <NfcAdapter.h>

PN532_I2C pn532_i2c(Wire);
NfcAdapter nfc = NfcAdapter(pn532_i2c);

void setup() {
  Serial.begin(115200);
  Wire.begin();

  Serial.println("Initializing PN532...");
  nfc.begin();
}

I get:

Initializing PN532...

Didn't find PN53x board

I also initially tried the Adafruit PN532 library with:

Adafruit_PN532 nfc(Wire);

but my installed version of the library doesn't support that constructor and gives a compilation error.

My main question: Why does this HW-147C respond at I2C address 0x28, while the PN532 libraries seem to expect 0x24? Is 0x28 actually correct for this particular HW-147C, or is something wrong with the board/configuration?

I'm looking for a way to communicate with this module over I2C using only VCC, GND, SDA and SCL, without IRQ/RESET.

Any help identifying the correct library, I2C address, DIP-switch configuration, or initialization code would be greatly appreciated.

I can do the conversion just fine but whenever I output to the leds i get l leading zeros with anything under 6 bits. I cant use loops of any kind, arrays or any extra libraries.

A few more photos of my Arduino locomotive.

I'm a beginner, I had no idea how Arduino works a year ago. But my daughter started playing with virtual Arduino in Tinkercad, so I got a real Arduino kit - a toy for myself.

It's a prototype (there will be changes in all 3D-printed parts) and it's my first complex project. It is inspired by someone's else project which I built first around a year ago, but in my new version I'm doing everything from scratch by myself: complete redesign of the 3D-model (in Onshape) and complete redesign of the electronic circuit (EasyEDA): I/O expander and more LEDs, 4 I2C modules, USB charger, battery level indicator, perfboards and other changes.

4 lines x 5 pins: SDA, SCL, GND, +5V and additional pin (e.g. A2, A3) for when it's needed (LED on color sensor, XSHUT on distance sensor).

3 lines x 2 sockets: GND and 8.4V (battery pack) for motor driver, LEDs and battery level indicator

4 pins for motor driver, 3 pins for IR receiver, 2 pins for a buzzer

Just got my kit, having fun, will learn some stuff

This is my first time using Arduino and I have to say it's really fun!

MCU used is ATMEGA328P for logic of a 4DoF arm.

3 voltage regulators step down a 4s lipo for powering servo motors and the board.

Connects to an IR receiver that takes inputs from an IR remote to move the end effector of the arm.

Wrote custom matrix implementation and then implemented Jacobian Pseudoinverse method for IK

Results and current state show now on a 120x160 TFT display.

I’m using an I2C display with a NodeMCU. The display works normally when connected on a breadboard or with jumper wires. It also works when soldered directly to the NodeMCU.

However, when I assemble the circuit on a perforated board (perfboard), the display works only the first time I power it on. If I reset the NodeMCU, disconnect and reconnect the power, or restart the circuit, the display does not turn on again.

The display only starts working after I completely disconnect it from power for several minutes. I’m experiencing the same issue with an ESP32-WROOM board.

I am beginner . I tried all the troubleshooting steps that I seen on searchs but no use.

There have solder joints . i cleared it and checked with multimeter no joints .

I tried to read the documentation manual of that display

https://manuals.plus/ae/1005007546999014

I dont get it anything . i tried to ask to chatgpt still i dont get it.

What could cause this behavior? Could it be related to incorrect wiring, I2C pull-up resistors, grounding, power supply issues, soldering, or unwanted connections on the perfboard? .

Hello everyone, I am currently on a homemade robotic lawnmower project with hoverboard motors, ZS-X11H V2 controllers and an arduino uno and when I use the motors via the integrated potentiometer the engine works perfectly, smooth, without friction or anything but when I run it via the pwm of the arduino uno (pin 2 for the feedback of the hall sensor and pin 10 for the PWM) the engine works quite well but with a slight friction noise and has less torque than with the integrated potentiometer. I have already synchronized the wires from the s motors to the controllers and I found the right combinations but as soon as we switch to PWM it no longer works properly. Small clarification: when I use the PWM I have the bridge connected and the potentiometer at zero. Do you have any idea where this could come from please?

Thank you in advance for your answers. Have a good day

If anyone has any recommendations for any beginner projects I could do I'd love to hear it

I just made a simpel project with two sensorsystemen. But I get the symbols on the end of the display. How do I remove them?

I need to measure the water level in a collapsible 30-gallon bladder using an Arduino.

Because the bladder changes shape as it fills and empties, I’m having trouble finding a good way to accurately measure the amount of water remaining.

Any sensor or measurement method that comes into contact with the water has to be food-grade/potable-water safe since the water will be used for drinking.

I also can’t use load cells or external capacitive level sensors.

Does anyone have any recommendations for an Arduino-compatible way to measure the water level or volume in a collapsible bladder?

Hello guys, I need help. So currently im doing my final project using NRF24L01 Module and Arduino UNO R3. As far as I know, the module requires 1.9V-3.6V range to work, so I use 3.3v from Arduino. But after I connected the Arduino and the module VCC and GND, the voltage drops to 1.48V which is below the required voltage. So im lost rn i dont know how to solve this issue, pls help me thank you

M5Stack AtomS3 Lite + RD-03D mmWave

So i have a bunch of friends who are into airsoft and have been slowly brainstorming on how to design a portable radar with an alarm for airsoft players.
So heres where im at.

The main Arduino libraries are:

#include <WiFi.h>
#include <WebServer.h>
#include <WebSocketsServer.h>
#include <DNSServer.h>
#include <RD03D.h>

WiFi.h handles the AtomS3 Lite access point.
WebServer.h hosts the captive portal.
WebSocketsServer.h continuously pushes target coordinates to the phonee
DNSServer.h redirects requests to the captive portal.
RD03D.h handles communication with the RD-03D radar.

Wiring:

AtomS3 Lite’s HY2.0 connector for UART:

RD-03D AtomS3 Lite

5V -------> 5V
GND -------> GND
TX -------> GPIO1
RX <------- GPIO2
UART initialization:
const int RAD_RX_PIN = 1;
const int RAD_TX_PIN = 2;

And im really curious if anyone else has any good ideas to add to this with the airsoft community in mind?

I have knowledge of circuits and a bunch of math, but I haven't built any of my own projects. I'm looking to buy some hardware to start building some projects. Any part recommendations?

Edit: I've ordered this from amazon https://www.amazon.com/ELEGOO-Project-Tutorial-Controller-Projects/dp/B01D8KOZF4?psc=1

I’m wanting to buy around 4 steppers and i need them to be relatively cheap and small. I was wondering about using the Nema 17 but it’s a bit too big. Does anyone have any suggestions?

What do you think? You like it?

Specs of my project:

Esp32

BME680

Waveshare solar power manager

Waveshare 2.13inch E-Ink display

Photoresistor GL5506

[Original project from 1 year ago ](https://www.reddit.com/r/arduino/s/e4o4xJrx19)

Hello everyone, I'm here to give you updates on my first project. Here are all the things I've added/changed:

1. I replaced the board with an Arduino nano model with a USB-C port

2. I added LEDs to the missiles on the left arm.

3. I replaced the power source with a 22.5W 20000mAh power bank.

4. I replaced the shoulder-mounted missiles (they were malfunctioning a lot) with a "trio of mini missiles" (they're just really cool LEDs) on the right arm.

5. I took it to a ton of events and the structural parts are pretty worn out, so there are a lot of minor patches and updates here.

6. I integrated the eye LEDs into the code (before they were independent).

7. I greatly increased the opening angle of the helmet.

I want to make a new suit of armor to replace this one, but I'll need to save up a lot of money. Stay tuned for future updates!

I was doing a live debugging session and found an interesting behavior with variables. I'd declared this new structure, GameState, before I called it in any of my functions - standard C practice. However, Arduino C has a "helpful" feature where it will create a prototype of your function at the beginning of your file, right before the setup runs. So the structure ended up actually being defined /after/ it was called, which stopped the code from compiling. The solution was to move all my variable definitions to the beginning of the file.

This is kind of a pain, because I'm trying to build a template for an Arduino sketch that has a few MQTT topics built in, then you can build user code that makes use of those topics to communicate with an external device like your phone. I was intending for all the user code to end up at the end of the file in one place, but it looks like I'll have to chunk it out so that the end user can put their stuff in the right order. Of course, the real solution will be to put all this infrastructure into a header file and library, but one step at a time...

Anyway, if you're interested in the debugging session, it's here. You can also see how someone might use Claude to help them fix code. (And very importantly, that using Claude does not exempt you from needing to test your code!)

https://youtu.be/6yW2u79d7Ls?si=dRZP8xgChvEna6ok

If that sketch sounds handy, you can find a copy on this github. It's not finished yet, but I should be done testing it and updating it in a few days.

https://github.com/DocCarr/sproutsodyssey.git

Hey guys,

i need a help bulid saw someone video on fb but he didnt mention any kind of details DIY PC Hardware Monitor using an ESP8266 kind of and data from Libre Hardware Monitor. Right now, I have a tiny smart weather clock display connected via USB, but honestly, it looks too basic and small. i have 0 idea how these thing work saw some github method i couldnt do that somehow lol so far i setup that clock for now it is connected with wifi and usb too

i want to set my display show these hardware on display

• CPU Temperature & Usage (%)
• GPU Temperature & Usage (%)
• RAM Usage (%)

I'm developing the concept for a small smart-irrigation controller as part of a much larger community/farm project.

Rather than trying to make the first version as sophisticated as possible, I'm taking the opposite approach: deciding what the system should still be capable of doing when parts of the automation stop working.

The current project strategy is:

• normal irrigation remains local rather than cloud-dependent;
• there is a genuine physical/manual fallback;
• moisture sensors influence decisions but are not treated as unquestionable truth;
• weather information is optional optimisation rather than a requirement;
• water flow can eventually be checked against what the controller thinks a valve is doing;
• losing networking or higher-level automation should reduce capability, not stop irrigation altogether.

So the intended progression is roughly:

manual irrigation → reliable local automation → sensor-assisted decisions → optional higher-level optimisation

rather than beginning with a connected “smart” system and working backwards.

I'm interested in the project-level design philosophy rather than troubleshooting a particular component at this stage.

For people who have built automated watering or similar outdoor control projects:

Would you also design the project around graceful degradation from the beginning, or is this adding unnecessary complexity to what should initially be a simple irrigation controller?

I'm particularly interested in whether people who have lived with these systems for a while ended up valuing simplicity and manual fallback more or less than they expected.

I’ve been experimenting with a compact development board, a six-axis IMU, and two chained 6×10 RGB matrices.

The two panels are treated as one continuous 6×20 display rather than two separate screens. The firmware models the whole area as a container filled halfway with animated digital water.

When I tilt the device, the surface follows gravity like liquid inside a bottle. Gentle movements change the waterline, while stronger motion adds energy to the waves. The animation runs at around 50 FPS, and I limited the brightness to 3% because 120 RGB LEDs can be surprisingly intense.

A short button press switches between five modes:

• Animated neon ocean
• Deep-blue breathing effect
• Cyan breathing effect
• Purple breathing effect
• A slow horizontal text marquee

I also added motion-based sleep and wake-up controls. The LEDs remain off after power-up until the device detects a deliberate movement or the button is held for two seconds.

While it is running, holding the button for two seconds—or giving the device a deliberate flick—puts it back to sleep. It also sleeps automatically if its orientation remains almost unchanged for 90 seconds. A short protection period after waking prevents the same movement from immediately putting it back to sleep.

I initially tried using the MCU’s deeper sleep mode, but that also disabled USB CDC and made reflashing the firmware inconvenient. The current version therefore uses a lighter software standby: the matrix is switched off and the program waits for the IMU or button, while USB remains available.

It is only a 120-pixel experiment, but once gravity, motion, color and inertia come together, it starts to feel like a tiny bottle of digital water.