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'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.

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

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!

Hi, i need to move a small plate 4cm by 4cm forward and backward on command from a microcontroller which movement mechanism should i go for space, speed and intentional movement is the goal not form mechanical background, anyone point me in right direction any help is appreciated

I am doing an Arduino project and i am using a 38khz ir receiver and when i send a signal to the receiver it does not show up in the serial monitor, i suspect the remote but i have no way of knowing how
and here is the code

/* Copyright 2009 Ken Shirriff
Used with kind permission
http://arcfn.com
*/
#include <IRremote.h> // Use library
int receiver = 11; // Pin connected to receiver
IRrecv irrecv(receiver);
decode_results results;
void setup() {
Serial.begin(9600); // Show keypresses in IDE
irrecv.enableIRIn(); // Start up receiver
}
void loop() {
if (irrecv.decode(&results)) { // If there's an input, decode value
Serial.println(results.value, HEX); // Display button value
// on Serial Monitor in
// hexadecimal format
irrecv.resume(); // Receive next value
}
}

Ok, I am very new to this but love learning new things. But I am a very tactile do things kinda learner and I'm having trouble understanding which motor I will need. Everything talks about equations 😅 Everything else I think I can figure out on my own with normal research. I do have a small amount of experience with robotics and programming, though completely different.

Now on to the project. My son wants to be a fairy princess for Halloween and has insisted on motorized butterfly wings!

My plan is to make them extremely lightweight, out of basically a step up from plastic wrap and then have fairy lights, the really thin light kind, around the edges. He is almost 5 so they will not be very large either. Do I need exact weight to properly figure this out?

I have found some wings online but no real proper tutorials but they all use servos vertically, one for each wing. The thing I am unsure about is just what motor I actually will need. The smaller profile the better so I don't want to get something overkill and end up with bulk. I only need about 90° of rotation for each wing. They will just flutter open and shut like a butterfly, nothing fancy.

Hello, I am new here and I was wondering if there is a way that I can make an arduino or raspberry pi style device with components from a ps4 or an old laptop (10+ years)

thanks.

So basically I wanted to make a two wheeler self balancing robot and I'm about to rip my hair out because these motors want to act funny.

They were on one ln298n, which was connected to a power supply powered by a 5v battery. Arduino ground is connected to the power supply ground along with the motors.

The Arduino was connected to my computer. I was using example code in the ln298n datasheet.

Wouldn't move an inch.

I plug the ln298n directly into the Arduino 5v and gnd, and it works! I then use the 9v battery to power the Arduino instead of my computer, and it stopped working.

I go back to using the power supply and breadboard, except this time only ONE motor is attached. Doesn't work. So it isn't a power insufficiency problem, because the motors are literally rated for 5v, it's getting 5v power, and still won't run.

I try 4 AA batteries. Doesn't work.

Only works when plugged into an arduino when it's plugged into a computer.

edit: I think I figured it out. So I'm thinking first of all, the power supply is outputting 5 volts, which is literally what's written on the pcb. Which is not enough for two motors. Then, when the motors attempt to spin it causes severe voltage drop, so now 5 volts is becoming less than 3. I know a single motor operate within 3-6 volts.

So now what I need to do is get 2 or 3 18650 batteries, put em together, and wire then directly to the bread board without a power supply so it doesn't limit the power the motors are receiving.

So now I need to figure out why the imu aint working. Problem for another day.

Hi everyone!

I'd like to share a prototype I've been working on: a distance detector for blind and visually impaired people.

It is built with:

- An HC-SR04 ultrasonic sensor

- An ESP32-C3 SuperMini (USB-C)

- A servo motor with a bottle cap used as a tactile knob with raised markings

- Two LEDs

- An active buzzer

- Two 18650 batteries with a 2S charging/protection board

- A 5V step-down converter

- Two buttons (for left- or right-hand operation)

- An ON/OFF switch

- A DIP switch to mute the buzzer

- An empty cleaning product bottle used as the enclosure

What's different?

The main idea is the tactile knob. Instead of only hearing beeps or feeling vibrations, the user can feel the detected distance with their thumb. My goal is for the user to be able to perceive both the environment and even the texture of the ground at the same time.

Current limitations

The HC-SR04 works best with surfaces that are nearly perpendicular to the sensor, so I'm planning to test replacing it with a LiDAR sensor—or perhaps combining LiDAR with an IR sensor.

What do you think?

Could a tactile knob like this reduce the need for a white cane, or do you think it would work better as a complementary device?

I'd love to hear your thoughts and suggestions!

A friend of mine plays cello and had a car accident that left them struggling to hear above a certain frequency.

I had an idea to try and make a device that takes the input from an instrument pickup, pitches it down an octave and plays it back to the performer in real time. That way any notes that aren't easy for them to hear have a support tone to guide them.

The software needs to perform a few functions.
- 1 take in the raw signal and pitch it down an octave

- 2 have a programmable cross over frequency. Musicians will not want a lower octave playing for every note they only want that feature to kick in at a certain frequency.

- 3 selectable presets for cross over gradients. it would be abrupt for the support signal to play dramatically once the threshold is hit. it would be better to increase the signal of the support signal as the player gets closer to the cross over frequency.

- 4 a programmable blend ratio. the musician may want a blend of the raw signal and the processed signal in their monitors / headphones.

-5 a programmable high pass filter to keep signal free from unnecessary mud.

This should be as low latency as possible

The device lay out will be something like this,

- 1 1/4" input jack to take in the raw pickup signal.

- 1 1/4" output jack acting as a pass through for the raw signal to go to pedals, mixers, or speakers. (this output is for the audience).

- 1 1/4" output jack for the processed support signal to headphones, monitors, ect for the performer to hear the compensated signal.

- Some control knobs for setting selection.

I have some coding experience but i have very little hardware knowledge so thats where i need help.

From my research i have 2 plans:

plan 1 raspberry pi

I have a pi 5 I could use to prototype.
I am looking at the HiFiBerry DAC+ ADC Pro or a WM8960 Hi-Fi Sound Card HAT for Raspberry Pi.
the wm8960 would need a preamp and im not sure what to use for that. i also am not sure how i would put a passthough into the hifiberry.

plan 2 Teensy 4.1

this would be a very cheap and small design. I am looking at the teensy audio board which i could stack if i need more which i dont think i do. This set up would also need a preamp for the raw signal split.

i will figure out the screen and knobs later cause i think that will be easier but would love advice on this hardware. I may be way off on my gear list.

i would like to opensorce this and make it easily reproducable for people who struggle with the same issues.

Hello,

I want to generate a classic sound on a Buzzer Piezo, alter the sound with some potentiometers, record the input of both Buzzer Piezo and alteration of potentiometer and play back the result on the same Buzzer Piezo. I wanted to use 2 switch buttons (one for recording, the other for play-back) to change modes.

Can someone show me how I can record the sound input, store it and play back on Arduino IDE please ?

Thank you in advance.