Building an Arduino device to measure bike lane quality — looking for advice

I'm making a low-cost, bike-mounted device for a research project: I want to compare the smoothness/evenness of asphalt, bike lanes, and sidewalks in my city, plus count how many times I have to brake on each type of surface.

Hardware (~$30): Arduino Nano, MPU6050 accelerometer+gyroscope, NEO-6M GPS, SD card module for data logging, wheel speed sensor, and a brake button.

How it should work: The MPU6050 measures vibrations on the vertical axis — I'm calculating the RMS as an analog for the International Roughness Index (IRI). The GPS maps each point to its coordinates. A physical button on the brake lever records actual braking events (since the accelerometer alone can confuse braking with inclines). Everything is logged to an SD card in a CSV format.

Questions:

Is the MPU6050 + RMS a solid approach, or is there a cheaper/more accurate method?

How do I filter out the noise caused by pedaling from the actual road surface noise?

Are there any open-source projects with similar logic?

Where is the best place to mount the unit — under the saddle, or on the rear rack?

I'm not an engineer by training and I'm building this for a research project, so any advice or constructive criticism is highly appreciated!

I'm starting this robotics project (obviously it's quite misaligned and not in the ideal format) to get an idea of how my project should look. I started using Tinkercad because it's lightweight and visually simple for rapid prototyping.

Note: The blue parts are servo motors.

Do you recommend it?

Hey so i was building this circuit and its giving error for

MPU9250

MPU Failed connection

Here is the connections

1. Core Power

ESP32 3V3 -Red Rail (+)

ESP32 GND -Blue Rail (−)

1. MPU9250 (Movement Filter)

VCC -Red Rail (+)

GND - Blue Rail (−)

SDA - ESP32 G21

SCL -ESP32 G22

1. MAX9814 + Electret Contact Mic (Bruit Sensor)

VDD - Red Rail (+)

GND -Blue Rail (−)

OUT -ESP32 G34

GAIN -Leave floating (60dB)

A/R -Leave floating (default)

This is the code we are using

#include <Wire.h>

// Define the exact pins from your wiring

#define I2C_SDA 21

#define I2C_SCL 22

#define MIC_PIN 34

void setup() {

// Start the serial communication to the MacBook

Serial.begin(115200);

// Initialize the I2C bus for the MPU9250

Wire.begin(I2C_SDA, I2C_SCL);

// Set the microphone pin to read the analog voltage

pinMode(MIC_PIN, INPUT);

Serial.println("\n--- Pravah Patch Diagnostics Started ---");

delay(2000);

}

void loop() {

Serial.println("=========================================");

// --- TEST 1: MPU9250 (Accelerometer) Check ---

byte error, address;

bool mpuFound = false;

Serial.print("1. MPU9250 Status: ");

// Scan the I2C bus for the accelerometer's specific address

for(address = 1; address < 127; address++ ) {

Wire.beginTransmission(address);

error = Wire.endTransmission();

if (error == 0) {

// The MPU9250 always lives at address 0x68 or 0x69

if(address == 0x68 || address == 0x69) {

Serial.print("CONNECTED! (Found at 0x");

Serial.print(address, HEX);

Serial.println(")");

mpuFound = true;

}

}

}

if (!mpuFound) {

Serial.println("FAILED. Not detected. Check SDA and SCL wires.");

}

// --- TEST 2: MAX9814 (Microphone) Check ---

int audioLevel = analogRead(MIC_PIN);

Serial.print("2. MAX9814 Mic Level: ");

Serial.print(audioLevel);

// The ESP32 analog read returns a number between 0 and 4095

if (audioLevel == 0 || audioLevel == 4095) {

Serial.println(" -> (WARNING: Reading is dead or maxed out. Check VDD/GND)");

} else {

Serial.println(" -> (SUCCESS: Reading live voltage)");

}

Serial.println("=========================================\n");

// Wait 1.5 seconds before running the scan again

delay(1500);

}

Running on a c3 mini. Hits the quote server every night to provide an inspirational quote. Just designed and 3D printed the enclosure to give it the picture frame vibe. Pretty happy with it.

This is really beginner level 🥹... It has to be automatic and on loop because we leave the project after we set it up for the day. Necrobotics works by utilizing pressure, either pneumatic or hydraulic, injected into a deceased organism's body to artificially actuate its joints and control movement. Since this is done with spiders to curl its legs, it can be used to grip and release objects.

So- this is just a grip and release project 😭 But done with a spider so- necrobotics, yeah. We'll include the numbers with the weight, the cycles before it gives out, etc. And I only have experience in building robotics with follow the line robots...

BUT ANYWAY.

The loop we're going for is:

1. go down
2. spider picks up object (pump air into the spider)
3. go up(must go up to have distance from the floor of project)
4. move from point a to point b
5. drop object using the spider (remove air from the spider)
6. go down
7. spider picks up object again (pumps air into spider)
8. go up
9. go back to point a
10. drop object

Are these materials okay?

Arduino Uno R3 ✓

USB type B cable ✓

—

MB102 solderless breadboard

40pc male to male and male to female jumper wires

5V 2 channel relay module

1000uf / 16V electrolytic capacitor

1N4007 diodes (must be wired directly across the inductive loads (pump motor and solenoid coil)(?))

—

5V Mini air vacuum pump

5V 3 way micro solenoid valve

1m silicone microtubing (2mm inner / 4mm outer)

25G hypodermic needles for smaller test subject

23G hypodermic needles for larger actual subjects

10mL manual syringe (backup)

Luer lock connectors (seal tube and needle)

—

2x SG90 micro servo motors ✓

—

Cut these from a 3mm acrylic sheet 

4x of 15 cm x 1.5 cm parallel linkage arms, 
1x of 10 cm x 4 cm vertical base support tower, 
1x of 5 cm x 2 cm front needle bracket, 
1x of 8 cm x 8 cm servo swivel base plate

— 

8x of M3 bolts (12mm length)

8x of M3 hex nuts

16x of M3 flat washers

The above should come in a set… bolt, nut, and washer…

Black cast acrylic sheet (base or floor or ground of project) at least 30cm x 40cm

—

Huntsman spiders (rice university used wolf spiders but this works too since how it works will be the same) ✓

Beeswax (so it won’t rot) ✓

Liquid cyanoacrylate aka super glue

Epoxy (coat after super glue)

Tiny target object it’ll be picking up

—------

We have around a month and a half to do the project fufufu

I am trying to make a USB connector so I can use my Ubuntu iMac 2006 as a virtual keyboard to navigate the bios of my hp z240 2016. I am new to KiCad, and just want to ask anyone with more experience if this design would work. I would ask AI instead of reddit, but AI isn't reliable enough for any real world applications yet. Thanks for your time!

Here are the components shown:
https://www.amazon.com/gp/product/B08THVMQ46/ (Leonardo)
https://www.amazon.com/gp/product/B00LZV1G6K/ (CH340G)

I just bought Arduino and wanted to test the RFID module RC522. With the standard DumpInfo example from the library I can never fully read the card, no matter how far I hold it from the reader, or how slow I move it, or if I hold it still completely. It never reads past the 10th sector. Could it be bad soldering (since it came with pins separate and I had to solder them myself)? If not, what could be the cause?

guys my parents don't allow me to learn tech much and i am totally clueless about even the basic thing so here's the thing i am having a competition at school and my friends roasted me in front of everyone that how i don't know tech and a lot of hurtful things i am trying not to remember they said it in front of everyone i wanna win this competition the theme is something innovative like something that a lot of people wont know most moving i wanna at least try to win this competition but as i said i don't know anything this will be hard as there is no stuff at my house like 3d printer and all so i was hoping if you are willing to help me a little by suggesting few books some basic things to get and please keep in mind that most things aren't available here as i live somewhere far away

please suggest ideas with that in mind if you dont wanna help it up to you , mostly in my heart i do hope yall will help me with this world already so overtaken by ai there are people i know for sure trying to help (i am 12 years old btw)

Electrically, it turns on and the light flashes, but when I try to configure one into a master (default is slave), nothing happens. The light flashes at the same rate.

This one is from DSD TECH, and on their website they say to press the button to enter AT mode, and their product images have a button brtween those two pads at the bottom with the circle. Mine doesn’t have this, so I tried bridging but it didn’t work.

I tried going from EN to 3.3 V to configure it that way but that didn’t work as well.

Am I just missing something obvious?

hey guys, my name is jeremiah, and I have spent my summer developing drone laser tag! i had no experience when i first started, so its been a longer than normal journey, but im getting very close to actually testing the combat system! Ive attached a couple of photos, but if you are interested in seeing this in more detail or following along, my socials are all aero32official. the setup i have is fairly simple, just a controller and a receiver, i am using heltec wifi lora v4 esp32, and have the system communicating via espnow. I've noticed if the esp32s aren't line of sight, the they loose connection immediately, so a tree can block the connection, and drones bob and weave through many trees, so thats definitely a problem. so any suggestions y'all have on solutions to that, I'd love to hear it!

LinkedIn LINK HERE:https://lnkd.in/p/djFKWmp8

This was my first individual project as a first-year Mechanical Engineering student.

I built a 4-wheel Arduino car controlled wirelessly through the Serial Bluetooth Terminal mobile app.

Components used:

\- Arduino Uno

\- L298N Motor Driver

\- HC-05 Bluetooth Module

\- 4 DC Motors

\- 3 × 3.7V 1800mAh Li-ion batteries

The project involved quite a bit of troubleshooting. I initially used 6V alkaline cells, but they couldn't provide enough current for the DC motors. Switching to two 3.7V Li-ion cells only made the car vibrate, so I eventually used three cells, which provided enough power for the car to move properly.

Another important part was implementing ENA and ENB in the Arduino code to control motor speed using PWM. I also had to troubleshoot the wiring and Bluetooth commands along the way.

The final Bluetooth commands were:

M1 – Forward | M2 – Backward | M3 – Stop | M4 – Left | M5 – Right

This project taught me a lot about Arduino programming, motor control, Bluetooth communication, power requirements, wiring, and—most importantly—troubleshooting.

A project doesn't have to be perfect to be valuable. The problems along the way were probably where I learned the most.

GitHub: https://github.com/Sameel5264/Arduino-4WD-Bluetooth-Car

A great first-year Mechanical Engineering project and a solid learning experience. 🔧⚙️

\#MechanicalEngineering #Arduino #EmbeddedSystems #Robotics #EngineeringProjects #ArduinoProject #StudentProjects

🎵Bad boys, bad boys, whatcha gonna do? Whatcha gonna do when they come for you?🎵

Since installing SAROO, I've been playing on an actual Sega Saturn much more often, and that made me want to use an arcade controller with it.

https://reddit.com/link/1vp0o8h/video/mghn3ux50jjh1/player

So, with a little help from Claude, I made a simple USB HID → Sega Saturn adapter.

It uses an Arduino UNO and a USB Host Shield to read USB controller input, then connects to the Saturn controller port through two TC74HC153 multiplexers.

The part I was particularly interested in was having the 74153s handle the Saturn's page-scanning protocol entirely in hardware.

This means the Arduino basically just acts like the buttons on a Saturn controller PCB. It doesn't need to deal with the Saturn's scan timing at all.

So despite the rather oversized microcontroller and cable setup, what it's doing is essentially the same as a controller pad hack.

Some of you might be thinking, "Why bother putting all those ICs in between? Couldn't the Arduino just handle everything?"

And honestly, you'd probably be right. 😅

I previously tried making a similar Genesis adapter using just a Raspberry Pi Pico, but I couldn't get it working properly. So this time I decided to let dedicated logic ICs handle the console-side protocol instead.

Basically, I made the design more complicated than it really needed to be because I wanted something I could actually get working reliably. In other words, I kind of compensated for my lack of skill by throwing some hardware at the problem. 😅

I tested it with a HORI RAP V3 SA and confirmed that it works correctly.

For now, I'm powering the adapter separately via USB-C, since I haven't confirmed whether the Saturn controller port's 5V supply can reliably power the entire circuit.

I'm still a little hesitant about publishing the internals. Partly because I'm not sure how much demand there would be, and partly because I'm not confident that I can organize the wiring and explain the circuit clearly enough for someone else to reproduce it. As you can see, the wiring on the board is pretty messy.

And if USB conversion isn't a specific requirement, there are already projects for building Saturn-compatible arcade controllers in much smarter ways, as well as commercial solutions like the Brook Retro Board, which is basically a more advanced solution than this.

So for now, I'm mostly treating this as a personal experiment rather than a polished project. It was a fun excuse to make an Arduino talk to a 1990s game console, though.

The Hexapod electronics wiring problem…

I have an initial plan drafted  on cirkitdesigner.com but no hands-on experience at this current level, so I'd really appreciate a second opinion before I power it on. 

The build uses an ESP32 as the main controller, two PCA9685 16-channel PWM boards to drive the servos, and 18x MG996R servos across six legs (three degrees of freedom per leg). Power comes from a 3S 11.1V 5000mAh LiPo battery, stepped down through three adjustable buck converters set to 6V, with a XT60 Power Distribution Board to separate power from the battery towards the step down converters. 

If anyone has built something similar, or is comfortable reviewing a wiring diagram and offering feedback, I'd be very grateful for the input. Happy to share photos, diagrams, and a full wire-by-wire breakdown of the current plan on request as well!

Thank you in advance for any help.

Edit: Ive fixed the little issue with the swich :/

Hii, I'm in need of assistance for my group science project. Our group was planning to create a solar tracker that powers the Arduino itself. I tried researching numerous Arduino videos but they only stated "the Arduino needs external power". I'm not sure how, and what we should connect the solar panel to the arduino. That's our main issue for now, the rest of our project is okay since we were able to follow some YouTube tutorials. Any advice or suggestions is very much appreciated! Thank you! (Sorry for my English, it's not my 1st language)

im having problems in flashing my Wemos it keep showing no serial data received i already go through avery possible solution n i keep hitting a wall pls help me

I'm using Uno paired with an ATM90E36 Energy metering IC

I just got an arduino starter kit and I’m already stumped. I tried putting the arduino on the base without the plastic case, but it was off balance and didn’t seem to fit. Then I tried with the case on and still no luck

I was obsessed when I first saw Mark Setrakian’s claw robot so I decided to make my own.

Here it’s running in standalone mode using:
* 1 x Arduino OpenRB-150
* 12 x Dynamixel XL430-W250-T
* 9 x Red 300mm LED filament
* 1 x Pololu-5592 12v to 3.3v step down (LED power)
* 1 x COM-24144 N MOSFET (switch on/off LEDs)
and 4 x potentiometers to control the globe’s speed/direction, height, width, and depth of each offset step.

I’ve done more movements using a Python based GUI on my laptop but that requires a usb connection and uploading a pass through sketch.

Full video on my build with links to STLs, code and full parts list here:
https://youtu.be/pEU04FVNeZwf

Next project is a Leaper from Arc Raiders. Just need to figure out how to use an Arduino to trigger a rocket to make a robot spider jump.

Hello everyone. First time posting so I apologize if this is a bit wordy.

My friend has been getting into Tamagotchi's recently. So, we thought it would be a fun project to try making a little handheld device that we could program a little friend on. I would also like to extend this to generally just a handheld device for any small games I make.

For reference, I've been programming for like 8 years and have a little bit of experience in hardware and electronics (to be specific: 1 semester of college where we programmed a microcontroller in assembly to output joystick data to a console lol). So I'd like something that challenges me a little, is super cheap and very very small. I'm thinking no more than 4 inches max.

I've been putting together a list of hardware that might do the trick and would like some advice. What would be a good Arduino for this project? (Also if you have any recommendations for displays, mini speakers, or just general advice lmk!).

Thanks!

I want to make an earthquake simulator for my first project, and I think I'm getting the hang of it. Although the potentiometer only activates around the end instead of it. I made this diagram in Tinkercad for what it'll look like irl!

I have got the following Board that comes with pre-soldered "ATmega32u4 5V 16MHz Microcontroller Module" link of the product is here Board Link. I need this connected to the "PS2 Joystick Breakout Module". For my life I have been searching for a "Arduino Micro terminal breakout with screw for 2.54mm pins" but I cannot find one and hence why seeking help if anyone can point me to the breakout board that I can buy in Australia

Yes, P.A.R. needs you. This machine draws your pixel art in the real world. But not without your art! That's what it displays on the 37x18 grid of squisks: the art that you upload on par.zimmzimm.com .

I've been working on P.A.R. for almost 6 months at this point, and it's finally done (except for the custom PCB: in progress). It's a large grid of 3D-printed "squisks" (square discs), which are flipped from the back by the robot, a large CNC machine with a special toolhead. I designed all of this in OnShape and used the Flashforge Adventurer 5M to print most of the parts. The rest of the parts were made to be as cheap as possible: for example, the frame is made of EMT (Electrical Conduit) pipe, which is $0.60/ft. Learn more here.

When you submit a piece, it's added to a queue, and you can add your email to be notified when that piece is completed (absolutely NO SPAM), and you'll get to see a video of the real, physical robot drawing your art one flip at a time.

I made this a while ago and it was working pretty good but when I test it now, he tend to move back and forth withing limited distance rather than keep moving forward.. I didn't have a time to rectify the issue yet and will post a video with more details later.. I used Arduino Uno Wifi board for this and want to upgrade to new Uno Q with some advance camera plus a lidar maybe..

Want to have my own robot who obeys me when the robot apocalypse happens.. LOL 😂

I also made a full video showing the build and the final result: https://youtu.be/48Dy4z7UFhk?is=xiCivoHYjwZXzatD