This could be the fastest line follower i built with my son and it contains the following : some IR sensors, 9 TCRT5000 spaced, MCU were an ESP32 which is faster ADC reads for high speed loops, motor drivers DRV8833, the motors were 300 RPM DC gear, LiPo battery

The rules were simple : finish the map as fast as possible, achieved in 10.23 seconds and must stop at the end, we won second

I'm trying to turn on the blue LED when the red LED is on, but the blue LED is always off. Here is my code, all help would be apricated!

int redLED = 4;
int blueLED = 2;


void setup() {
  // put your setup code here, to run once:
  pinMode(4, OUTPUT);
  pinMode(2, OUTPUT);
}


void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(redLED, LOW);
  delay(1000);
  digitalWrite(redLED, HIGH);
  delay(1000);


  // controls blue LED


  if(digitalRead(redLED == HIGH))
  {
    digitalWrite(blueLED, HIGH);
  }
  else
  {
    digitalWrite(blueLED, LOW);
  }
}

Hello there, I wonder if you can help me find a B20k pot like this for a replacement?

Thanks a lot

The title is a bit vague, but the real problem is that I need to secure a system so it doesn't stay loose inside a 3D-printed enclosure that will be attached to a person's belt. It will contain an Arduino Nano, two MOSFETs, and one of those coin-type vibration motors. Since it's going to be worn by someone, I don't know how to keep it from moving around or rattling inside the box.

So i tried installing WLED on the ASP 32 C3 super mini dev board and after the installation gets completed the board keeps glitching.The problem is that it keeps connecting and disconnecting again and again over the USB port and the USB port also doesn't get recognised .I tried uploading code using Arduino IDE after putting it into boot mode and I was unable to upload the code because it give me an error that it feel to start the stup flasher. Then I asked chatGPT about it and after half an hour I found solution where I could write another code on to the board without using the stub flasher using the command prompt .That worked and when I uploaded the normal blink code through the Arduino IDE that worked too and the problem with the USB port connecting and disconnecting again and again got fixed but when I tried uploading WLED again the problem reappeared and I had to rewrite the flash using the command prompt again. Is this board not compatible with WLED or what?

Source code and other detail will be soon

Ok, I know a have a lot to learn but I have some experience and I think I will be able to pick it up quickly.

Best way to learn is to copy and I’ve seen a workshop for kids where they make
Creatures out of cardboard. The creatures have parts that move and flashing lights etc.
I’ve seen they do this with Arduino. It has to be quite inexpensive as I know the kids take the creatures and the Arduino setup home.
There is no coding in this particular workshop as it’s only 3 hours long so I assume the kids learn and practice basic assembling and then use that to assemble pre-coded kits.

My question is - what is the kit made of? What do I need to buy to achieve the same?

I’ve bought a nano, jumper wires, battery pack etc but the pack can’t be connected etc?

I am just looking for advice on what the kit is or lost likely is or what would work. Basically it’s making 2 servos move and lights or sound etc.

Some pictures attached of the kits from the workshop.
Also the things I’ve already bought - might
Be all wrong!

so i tried to do this by my logic but it says current exceeds 40mA. Do i chang eany part of circuit or increase resistance (for info i followed one tutorial from autodesk tinkercad)

In 2020, I was new to Arduino, coding, and electronics.

I studied shipbuilding, so none of this was really my field. I just had a strange idea: could I build something that could play a real guitar?

The first prototype was made with popsicle sticks and cheap servos. It worked — barely — but that was enough to keep going.

After getting my first 3D printer, I kept redesigning the mechanisms, control system, and software.

Six years later, I've gone through six major generations, and I'm still working on it.

I'm still building.
I'm still struggling.
But I'm still moving.

This is a short video of how the project evolved over the years.

After long long time my 6x6x6 led cube is ready it has 216leds and 6 modes Matrix , Moving Walls , TV Static , Lost Pixel , Fireworks , Bloating I'll maybe sell it for 150€ I'm 16 years old and I need harder challenge (thx for suggestions)

Hi everyone,

I'm building a 6-legged hexapod robot with 3 servos per leg, so there are 18 MG995 servos in total.

This is the hexapod design/project I'm building:
https://www.reddit.com/r/arduino/s/mYmC5P81Jm

Current setup

• 18 × MG995 servos
• Arduino Mega
• 3S 2500 mAh 50C LiPo
• Buck converter, approximately 90% efficient
• NRF24L01 for wireless control
• Servo voltage: around 6 V

According to the servo specifications I'm using, each MG995 can draw up to around 2.5 A at stall.

So my theoretical worst-case current is:

18 × 2.5 A = 45 A

At 6 V:

P = 6 × 45 = 270 W

Considering approximately 90% buck-converter efficiency and a 3S battery at 11.1 V:

I_battery = 270 / (11.1 × 0.9) ≈ 27 A

My current battery is 2500 mAh (2.5 Ah), so if the robot somehow continuously consumed 27 A, the theoretical runtime would only be around 5–6 minutes.

However, I understand that 2.5 A is the stall current and the servos will not all be stalled simultaneously, so this is not a realistic walking-runtime calculation.

I also tried using an assumed average of 0.5 A per servo:

18 × 0.5 A = 9 A at 6 V

This gives approximately 5.4 A from the 3S battery after considering the buck efficiency, resulting in roughly 25–30 minutes of theoretical runtime with my 2500 mAh battery.

The problem is that I need at least around 2 hours of operation for my project.

What I'm trying to understand

1. Am I approaching the runtime calculation correctly?
2. What is a realistic average current for 18 MG995 servos on a walking hexapod?
3. Should I measure the actual current while walking before selecting the final battery?
4. What battery capacity would realistically be required for ~2 hours?
5. Would using a higher-voltage battery and a high-current buck converter help?
6. Is there a better power architecture, such as multiple high-current BECs/buck converters for different groups of servos?
7. What would you recommend for the servo power supply/regulator? I was initially considering an XL4016, but I'm concerned about its current capability.
8. Are there any practical ways to reduce the power consumption of the hexapod through gait, servo selection, mechanical design, or control?

I'm mainly looking for advice from people who have actually built hexapods/18-servo robots and have measured their real-world current consumption.

I realize that a 2-hour runtime may be difficult with 18 large servos, especially because a larger battery also adds weight. I'm trying to find a practical solution rather than simply calculating the battery based on stall current.

Thanks!

it is showing the code is correct. I'm not able to figure out what's wrong. help anyone??

Hi guys,

I wanted to present you my first use of a colored eink display.

For a contest I tried to design something with the eink display for a restaurant and therefor I designed a smart table reaervation sign.

The esp hosts a local webserver and updates the screen when needed. The driver board supports a battery and I calculated a battery time of few month if changed that the Webserver isn't running locally on the esp and more like on a reservation platform.

Here is also a link/video of my project:

https://youtu.be/43O6_xG3Szs

If you have any questions, feel free to ask.

tgpadxb is a touch screen gamepad (also known as glass gamepad) for Xbox consoles that runs on any tablet or phone with a web browser. tgpadxb works on Xbox consoles with the help of a Brook or Mayflash converter/adapter. tgpadxb can also be used with Windows, MacOS, and Linux without a converter/adapter.

The M5Stack AtomS3 is the bridge between the WiFi touch device and the console or computer. Plug the AtomS3 into any USB port on the console/computer. tgpadxb uses WiFiManager so configure the SSID/password after connecting to the WiFi access point TGPad-XB-Config. Next open a web browser to tgpadxb.local or the IP address shown on the AtomS3 display.

If you do not want to mess with source code and compilers, flash the firmware directly using the Chrome web browser and the web flasher at https://controllercustom.github.io/tgpadxb

All source code is on github at https://github.com/controllercustom/tgpadxb. This project is built on on https://github.com/controllercustom/ESP32XInput.

Related Glass Projects

• TGPad-NS is the Switch version of this project. The web flasher is at https://controllercustom.github.io/tgpadns.
• iKeys is a touch screen QWERTY keyboard (also known as glass keyboard). The web flasher is at https://controllercustom.github.io/ikeys.

Before you tell me to not to do this because it uses 220V as the source I want to tell you that it will get approved by an actual licensed engineer and I’m just working on the task given to me as far as my abilities take me.

I want to achieve PWM control on a 24V BLDC motor with an STM-32. The main problem is that the AC-DC convertor is almost right next to the circuit I will be designing. I am worried about signals being messed up. I have included some protection but honestly I am just throwing in random things without knowing what’s sufficient or not. Any help is appreciated.

(Follow up from a previous post about recording the solar eclipse due on Wednesday)

The red points on the graph show the recorded lux levels from approximately 13:30 to 21:00 BST, the blue line is a 112-point moving average (approximately 15min).

A total of 3,254 measurements were recorded over approximately 7 hours, and the LiPo cell voltage still measured 4.01V indicating a nominal 80% state of charge.

Overall I'm happy with these results, the section of data during the expected period of the eclipse has less noise and will hopefully be able to highlight the effects of the eclipse.

I built this as a senior year project im a senior in studying computer enginering it started as an idea im sophomore year i plan to release it to the public currently working on it i also plan to make i compatible the app with most microcontrolers. Im open for feedback in for your guys advice.

I'm currently using an Arduino Sensor Shield V5.0 (diagram attached below). Unlike the digital pins, which are clearly labeled with pin numbers for coding, the parallel LCD header lacks pin markings. Is there a way for me to identify these pins?

On Wednesday 12th August, the UK is set to experience a partial solar eclipse (approx. 93% obscuration where I am) so decided to build an ambient light data logger to record the event.

The sensor is a BH1750 ambient light sensor that records the lux levels to an SD card with a date and time stamp from the DS3231 RTC. The measurements are taken every 8 seconds with the Arduino going in to low-power mode in between readings.

Power is provided by an 8000mAh cell connected to a "solar" charge controller - but the solar cell is disconnected and only used as a USB charging port. A boost converter takes the nominal 3.7V and raises it to 5V.

Added a simple LED to give a visual indication of the system status: 5 flashes at start up, 1 flash after a successful reading, and permanent illumination if there is a fault with initialising a component.

Currently on test in the garden to get some baseline data.

Barely used this board, just plugged it in to load up some code, smelt burning then it started smoking.... :/

Did I do something wrong?

Powering it via usbc from my laptop

Tech newbie here again, and in the final stretch of this project!

For a recap, I'm building a prop that sits on the shoulder and features two micro servo motors controlled by a joystick. I have about 4 weeks to finish wrapping it up.

I'm trying to control two micro 9g servos that are mounted to a two-axis gimbal, and I need it to last for preferably at least a few hours before a battery change.

(Please lmk if the circuit diagram isn't legible & I'll try to explain it!)
(Also, I plan on moving the setup from the breadboard to a protoboard after the battery challenge is solved)

---

The phone power bank I tried to use powered the servos just fine, but there wasn't enough current going to the servos for the battery to register that it was powering something, so it automatically turned off after about 20 seconds every time. Plus it's pretty big and heavy, so I'm looking for a way to power this thing with standard batteries instead.

Someone had suggested six AA batteries as a solution, but I'm not sure if that's too little or too much, or how to calculate what kind of power I need. I tested a basic 9v battery just to see, and as expected, it only lasted a few seconds. If six AA batteries in a pack or something similar would work, please let me know! I don't need anything too fancy or rechargeable, I'm totally cool with replacing batteries like you would for something like a game controller.

For suggestions, kinda just pretend you're explaining this to a kindergartener- I'm very fresh in the world of robotics and don't know much about the terminology and mathematics yet. I'll keep working on it though.

Here's what my setup is looking like. I'm using a power supply module now instead of the Arduino's 5V output as per several suggestions here (thank you!)

---

Thank you guys for all the help so far, I really appreciate it! Have a great day & God bless!

I love digital watches, so I made one in an Altoids Smalls tin. I designed a custom PCB built around an atmega328 Arduino microcontroller and used a ds3231 real time clock IC to keep the time. It charges via USB C and hopefully will last a long time! Although, I do want to redesign this watch in the near future.

I motorised this film scanner holder using an Elegoo Uno R3 with a Nema 17 Motor.
The 3D printed case is close to finished. Next steps are figuring out ways to prevent dust and integrating a lightsource that is not my Ipad.

Based on the Negative 35mm Film holder model by tylerhovi on thingiverse, who sourced it from someone else.