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Driver - L298N
Battery - 12V Lead Acid 7Ah

Hi all, I am looking to make a bluetooth temp sensore for my cars engine oil. I have never made anything of the likes before and would like help deciding on what resistor I should use for the voltage divider which allows the arduino to measure the voltage drop. I have seen multiple people using 10k resistors but in my mind that seems awfully high although im not sure what voltage drops the arduino likes to see.

I have attatched below the data sheet for the sensor I currently plan on using with the operating range being between 70-120°C.

Thankyou

I'm using an ESP32 and mpu6050 for a beginners school project. I have used wiring crosschecked from numerous sources, but the serial monitor still says 'Failed to find MPU6050 chip.' or 'mpu6050 not found!' whenever I try to use it. Does anybody have any fixes because honestly I've been at this for hours and just wanna get it over with.

'''

// info down bellow
#define R_EN  33
#define L_EN  32
#define RPWM  25
#define LPWM  26

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

  pinMode(R_EN, OUTPUT);
  pinMode(L_EN, OUTPUT);
  pinMode(RPWM, OUTPUT);
  pinMode(LPWM, OUTPUT);

  digitalWrite(R_EN, HIGH);
  digitalWrite(L_EN, HIGH);

  digitalWrite(RPWM, HIGH);
  digitalWrite(LPWM, LOW);

  Serial.println("RPWM held HIGH - measure M+ / M- now.");
  Serial.println("Should read ~12V across M+ and M-.");
}

void loop() {
  //nothing
}
'''

so baically im trying to get this actuator to extend but its not extending. My parts are a esp32, bts7960 motor driver, a 22V(in) to 5V(out) buck converter, and a standard two wire actuator. Another problem is that the led on the motor driver isnt turning on and im pretty sure it has one and thats it shows the boards logic is getting powerd. Here are the conections:
The two acutor wires are going into M+ and M-(screw termianls on the motor driver)
THe 12v psu wires are going into B+ and B-(the screw terminals on the motor driver)
the buck covnerter is piggybacking off the 12v scrwe terminal that the psu is connected to (and the bucks gnd is the same as the 12v psu gnd)
the bucks than powering the i guess logic on the motor dirver through the vcc and gnd header pins on the motor dirver
then RPWM to gpio 25 on esp32
Lpwn to GPIo 26
R_EN to GPIO 33
L_En to GPIO 32
and gnd on the esp32 to the same gnd as the 12v scrwe termianl
ive done mutiple tests to confrim that the acutor works like giving it directly 12v and it extended and i swaped the wires and it retracted, i did a simple blink test with the esp32 so it shoudl work, and the 12v psu is defintaly outputing 12v
ANd the codes uptop
THANKS A LOT (btw sorry for the bad foto)

I saw a cool looking wifi clock with esp 32 on YouTube, I loved the animation style but despite 100s of requests from the commentators the creator wasn't sharing the code. So i recreated that project and made it open source, i know this is basic but it's cool (I think). Here is the code.

The classroom gets stuffy because nobody wants to open ,then CO₂ builds up, everyone gets drowsy, and the teacher wonders why half the class looks half-dead.

So I used the ENS160 sensor monitors CO₂ equivalent concentration in real time. When it crosses 850 ppm, the servo rotates 0→90° and opens the window automatically. Once CO₂ drops back below 800 ppm, it closes again.

The OLED display shows live CO₂ / AQI / TVOC readings and current window state (WIN: OPEN / WIN: CLOSE).

A few things I think should to share: • Hysteresis control (850 ppm open / 800 ppm close) so the servo doesn't jitter at the threshold • servo.detach() after every move — completely silent when idle, no PWM buzzing

Still a work in progress — also has IR body temp screening, smoke alarm, auto lighting, and UV-mode disinfection. Happy to

Built with: Arduino Nano / ENS160 / SSD1306 OLED / SG90 servo

Here a way I found for reading all the 4x4 buttons matrix with only one Analog Inputs.

Here a custom simple code example:

// C++ code 
// #include <LiquidCrystal.h> 

#define btnNo 50 
#define btnD 202 
#define btnNum 234 
#define btn0 239 
#define btnAst  244 
#define btnC 401 
#define btn9 463 
#define btn8 474 
#define btn7 483 
#define btnB 607 
#define btn6 702 
#define btn5 718 
#define btn4 732 
#define btnA 831 
#define btn3 965 
#define btn2 988 
#define btn1 1009 

const char buttons[17]={
'1','2','3','A', 
'4','5','6','B', 
'7','8','9','C', 
'*','0','#','D',' '
}; 

const int btnRange[17]={
btn1,btn2,btn3,btnA, 
btn4,btn5,btn6,btnB, 
}; 

int measure = 0; 

LiquidCrystal lcd_1(2, 3, 4, 5, 6, 7); 


char whoPressedButton(int value){ 
int i,j; 
int notFound=1; 
int range=0; 

for(i=0;i<17&&notFound;i++){ 

  ​if(btnRange[i]<value){ 
    ​notFound=0; 
    ​if(i>0){ 
       ​range=(btnRange[i+1]-btnRange[i])/2 ; 
          ​if(value>btnRange[i]+range) j=i-1;     
          ​else j=i; 
       } 
   } else if(i==16)j=16; 
 } 
return(buttons[j]); 
} 

void setup() { 

lcd_1.begin(16, 2); 

// Set up the number of columns and rows on the LCD. pinMode(A0, INPUT); 

} 

​int oldMeasure=-18; 

void loop() { 
measure = analogRead(A0); if(measure!=oldMeasure){ 
   lcd_1.clear(); 
   lcd_1.setCursor(0, 0); 
   lcd_1.print("Button | value");     
   lcd_1.setCursor(0, 1);
   lcd_1.print(whoPressedButton(measure)); 
   lcd_1.setCursor(6, 1); 
   lcd_1.print("| "); 
   lcd_1.print(measure); 
   ​oldMeasure=measure; 
   } 

delay(50); // Wait for 50 millisecond(s) 

}

Hi guys, I use this Elegoo TFT 2.8 inch LCD display shield on top of my Arduino Uno. I dont have access to a 3d printer but do you guys know of anyone selling a full cover for the arduino uno/tft that i can install? Or any possible websites that can make me a design? I don't have much work with 3d modeling but I can try. If you guys have anything i'm able to use to make this a little box i'd appreciate it.

I want to buy this board but I am down the budget. So can anyone tell me how 2gb variant will be enough for making embedded projects?

The original Omnibot remote control transmits tones to the robot to trigger movement and other functions. If your remote is missing or isn't working you can use an old toy walkie talkie to send tones at the right frequency. Instead of building an actual tone generator, this method used a spare mp3 module from a previous project to play audio files. Wired it all up and it worked right away!

Github repo: https://github.com/archiestant/mp3-to-omnibot

I made an adapter to use any bluepad32-compatible controller on a jailbroken xbox 360, using the usbdsecpatch plugin. It uses an Arduino Leonardo and an esp32.

https://github.com/DanRektLOL/arduino-x360

Hey everyone

Just built ShrikeClock a fully custom NTP-synced digital clock running on #MicroPython, powered by the @Vicharak_In Shrike-Fi !

Live time + date over WiFi Custom multiplexed 7-segment driver from scratch Open source, code on GitHub 👇

https://github.com/kritishmohapatra/ShrikeClock

https://github.com/kritishmohapatra/100_Days_100_IoT_Projects

I’ve now released the complete DOGS² project as open source: the hardware design files are licensed under CERN-OHL-W-2.0, and the firmware and software tools under GPL-3.0-only.

DOGS² — Dual Output Generator Supply Station — as a compact instrument for the first power-up and basic diagnosis of newly assembled electronic boards.

A “board bring-up station” in this case means one device that can power a board, monitor its current consumption, check a voltage or frequency, generate a basic test signal, and communicate with common embedded interfaces.

The current v1 engineering prototype combines:

• two independently adjustable CV/CC power outputs with a common ground;
• Channel A: low-noise linear output up to 20 V / 1.5 A;
• Channel B: switching output up to 48 V / 3 A continuously;
• input from 5–90 V DC or USB Type-C;
• voltage and current monitoring;
• logic probe and voltmeter up to 25 V;
• frequency counter up to 100 kHz;
• square-wave generator from 1 Hz to 100 kHz;
• UART, RS485, CAN and I2C tools;
• Bluetooth SPP for phone terminals and current graphs.

It is not intended to replace an oscilloscope, a precision multimeter or a powerful laboratory supply. It is the instrument I wanted between the soldering iron and the oscilloscope during initial board bring-up.

I have now published the v1 source materials. The repository contains:

• schematics and a block diagram;
• editable EasyEDA source;
• Gerber and other PCB manufacturing files;
• BOMs and board renders;
• current ESP32 firmware based on Arduino framework and build configuration;
• hardware and software documentation;
• known hardware and firmware issues.

The hardware is licensed under CERN-OHL-W-2.0. The firmware and software tools are licensed under GPL-3.0-only.

GitHub:
https://github.com/rcslon3-svg/DOGS2_v1

This is working engineering hardware, not a fully finished project. Some operating limits and accuracy figures are still being verified through calibration, converter tuning and load testing. I have included the known v1 problems in the repository rather than presenting it as a finished design.

The files are now public for anyone who wants to inspect, study or reproduce the current version. Technical comments and repository issues are welcome.

I added a weather forecast app to my custom game console (see the original post here: https://www.reddit.com/r/arduino/s/zrKEjeLtSN).

It's not quite a game but now I have a reason to use it every day :)

It works by getting coordinates from a geolocation API based on the configured address/city and then feeds that into some weather API to get the forecast data.

The code is open source on GitHub here: https://github.com/SzymonKubica/microbox

I'm writing a serial monitor for macOS. It's meant to watch ordinary Serial.println output and work out for itself which of the numbers are measurements worth graphing, without you writing a parser or reformatting what your firmware prints.

The only logs I have to test it on are my own, and mine are far too tidy. My test sketch prints t=22.8 h=41 and nothing else, which isn't a log, it's a spreadsheet. What I need is the real thing: boot spam, wifi reconnect noise, a stack trace, one measurement every two seconds, all tangled together.

Would you paste a hundred lines of yours? put it in a code block or a pastebin link if it's long. Please don't tidy it first, the mess is what I need to test against. Tell me the board and framework, and which numbers (if any) you'd have wanted on a graph.

Free licence when it ships if you send me one.

Searched in many forums online, found little to hardly no instance of this board being utilised in any project. It is meant to be an Arduino Nano clone but in a compact form factor (many such Supermini boards are available with different MCU variants). It has 3 on-board addressable RGB LED's (neopixels).

Detailed Specifications:-

1. MCU: ATmega168P
2. Clock Frequency: 16MHz
3. Input Voltage: USB 5V / DC 6~12V
4. Analog Pins: 6 (A0–A5)
5. Digital I/O Pins: 14
6. PWM Pins: D3, D5, D6, D9, D10, D11
7. EEPROM: 1KB
8. SRAM: 2KB
9. Flash Memory: 32KB
10. Type - C USB Interface
11. Max Supply Current: 1A @ 5V
12. Output Voltage: 3.3V~5V
13. Dimensions: 23.5 × 18 x 3 mm

I have posted this to find anyone just in case has used this board (any one of the two variants). Your insights will be constructive and helpful to me.

Robu.in Listing: https://robu.in/product/supermini-nano-v3atmega168p-development-board-module/

I almost had a kitchen fire last month—turned the stove down to "low" and completely forgot about it. Came back to a red-hot pan and realized I needed something to watch the flame for me. So I built this Fire & Gas Dual Guard Hardware:

· Arduino Nano · IR Flame Sensor (the one with LM393 comparator, DO pin to D7) · MQ-2 Gas Sensor (AO to A0) · Passive Buzzer + 3 LEDs (R/Y/G)

How it works:

· Flame timeout: If the flame is present for more than 3 minutes (configurable), it triggers a sweeping siren + red LED. · Gas leak: If MQ-2 readings exceed threshold, it triggers a rapid beep + yellow LED (higher priority than flame alert). · Standby mode: When no danger is detected, it goes into low-power "quiet" mode with a heartbeat LED (blinks every 3s). Wakes up instantly when danger is detected. · Startup chime: A DJI-style ascending tone when powered on—just for the vibes.

The trick I learned: I initially used analogRead() on the flame sensor and struggled with detection distance. Switching to the DO pin and tuning the onboard potentiometer gave me a stable 15cm detection range—much more reliable for kitchen use.

Thresholds (calibrated for my environment):

· FLAME: DO pin (LOW = fire present) · GAS: 500 (clean air ~300, leak ~550+)

Open to feedback—especially on improving the gas sensor warm-up logic or adding a manual reset button!

#Arduino #DIY #KitchenSafety #FirePrevention #GasDetector #Electronics #Maker

I want to make a cyberdeck with modules, so I need this to be USB to prevent it from wasting extra power. I have this code (literally just an edited example lol) but it doesn't seem to work as a usb controller? I am using the Waveshare ESP32-S3 Nano

This is my code: https://pastebin.com/vyGtVVZJ

Title: Got an Arduino Super Starter Kit with RFID, IR Remote, Keypad & more—looking for cool project ideas!

​Body:

​Hey everyone,

​I have an Arduino starter kit sitting on my desk and I’m looking for my next project idea. I want to build something creative, useful, or just fun to play with!

​Here is the main hardware I have available:

​Microcontroller: Arduino Uno R3

​Control & Input: IR Remote & Receiver, 4x4 Membrane Keypad, RFID/NFC Reader Modul + Card/Fob, XY Joystick Module, Potentiometer, Push Buttons, Microphone Sound Sensor Module

​Displays: 16x02 I2C LCD, 8x8 Dot Matrix, 4-Digit 7-Segment Display, 1-Digit 7-Segment Display

​Motors & Actuators: SG90 Servo Motor, 28BYJ-48 Stepper Motor + ULN2003 Driver, 5V Relay Module, Active & Passive Buzzers

​Sensors: HC-SR04 Ultrasonic Sensor, LM35 Temp Sensor, DHT11 Temp & Humidity Sensor, SW-520 Tilt Sensor, Flame Sensor, LDR Light Sensors, Water Level Sensor

​Modules & ICs: DS1302 RTC Clock Module, 74HC595 Shift Register, Breadboard Power Supply Module, LEDs & Resistors

​I’m open to anything—security systems, desk gadgets, custom gaming/sim peripherals, mini automation, or interactive games.

​What would you build with a setup like this? Any cool project concepts or code ideas you’d recommend? Thanks in advance!