Arduino Uno R3
Arduino Uno R3 का इंटरैक्टिव पिनआउट — PWM, I2C, SPI और analog पिन, करंट की सीमा, Arduino IDE और PlatformIO सेटअप, और कंपाइल-जाँचा कोड।
सामुदायिक ड्राफ़्ट — गलती बताएं
Uno R3 क्लासिक 5 V बोर्ड है: 16 MHz पर ATmega328P, एक USB-serial चिप (ओरिजिनल में ATmega16U2, भारतीय क्लोन में ज़्यादातर CH340), 5 V रेगुलेटर, और ऐसे हेडर जिन पर लगभग हर shield फ़िट हो जाती है।
इसमें Wi-Fi नहीं है और RAM सिर्फ़ 2 KB है, पर यह सीधा-सादा है और छोटी-मोटी गलतियाँ झेल लेता है — इसका 5 V लॉजिक ज़्यादातर hobby मॉड्यूल से मेल खाता है, और Playground इसी बोर्ड को पूरी तरह emulate करता है।
पावर USB से दें, या barrel jack या VIN पर 7–12 V दें। USB पर 5V पिन कुछ सौ mA दे सकता है; 3.3V पिन सिर्फ़ लगभग 50 mA।
इंटरैक्टिव पिनआउट
किसी पिन पर होवर या टैप करें — उसके फ़ंक्शन और सावधानियाँ दिखेंगी। फ़िल्टर से सभी I2C, ADC या बूट पिन देखें।
- Safe for most uses
- Works, with a caveat
- Avoid unless you know why
- Power / control
करंट का ध्यान रखें: हर पिन 20 mA, पूरी चिप 200 mA। 220 Ω रेज़िस्टर के साथ LED ठीक है। रिले, मोटर, बज़र और LED स्ट्रिप के लिए ट्रांज़िस्टर या ड्राइवर मॉड्यूल चाहिए — इन्हें कभी सीधे पिन से न चलाएँ।
आउटपुट 5 V लॉजिक, इनपुट भी 5 V लॉजिक। Uno के 5 V आउटपुट से 3.3 V मॉड्यूल (ESP-01, कई सेंसर) ख़राब हो सकते हैं। लेवल शिफ़्टर या डिवाइडर लगाएँ, और 3.3 V पार्ट को 3.3V पिन से तभी चलाएँ जब वह ~50 mA से कम लेता हो।
D0 और D1 ख़ाली छोड़ें। ये USB serial की लाइनें हैं। इन पर कुछ भी जुड़ा हो तो अपलोड रुक सकता है और Serial Monitor में कचरा दिख सकता है।
कंप्यूटर सेटअप
- Install Arduino IDE 2.x from arduino.cc.
- Boards Manager → install Arduino AVR Boards (we compile against avr 1.8.8).
- Tools → Board → Arduino Uno, then pick the port that appears when you plug the board in.
Your platformio.ini:
[env:uno]
platform = atmelavr
board = uno
framework = arduino
monitor_speed = 9600[env:uno] platform = atmelavr board = uno framework = arduino monitor_speed = 9600
पहला प्रोग्राम
// Blink the on-board LED (pin 13) of an Arduino Uno R3 or Nano.
void setup() {
Serial.begin(9600);
pinMode(LED_BUILTIN, OUTPUT);
Serial.println(F("FlashReady: blink started"));
}
void loop() {
digitalWrite(LED_BUILTIN, HIGH);
delay(500);
digitalWrite(LED_BUILTIN, LOW);
delay(500);
}// Blink the on-board LED (pin 13) of an Arduino Uno R3 or Nano.
void setup() {
Serial.begin(9600);
pinMode(LED_BUILTIN, OUTPUT);
Serial.println(F("FlashReady: blink started"));
}
void loop() {
digitalWrite(LED_BUILTIN, HIGH);
delay(500);
digitalWrite(LED_BUILTIN, LOW);
delay(500);
}आम एरर
avrdude: stk500_recv(): programmer is not responding
गलत पोर्ट, गलत बोर्ड, या D0/D1 पर कुछ जुड़ा है। USB लगाने पर जो पोर्ट आता है वही चुनें, Tools → Board → Arduino Uno सेट करें, D0/D1 से तार हटाएँ और दोबारा कोशिश करें। CH340 वाले क्लोन को उसका ड्राइवर चाहिए — हमारे ड्राइवर लिंक देखें।
पोर्ट धुँधला (greyed out) है या दिख ही नहीं रहा
सिर्फ़ चार्जिंग वाली USB केबल या CH340 ड्राइवर नहीं है। ऐसी केबल आज़माएँ जो पक्का डेटा चलाती हो; ड्राइवर सिर्फ़ wch-ic.com से इंस्टॉल करें।
Sketch too big / low memory की चेतावनी
Uno में सिर्फ़ 2 KB RAM है। स्थिर टेक्स्ट को F("…") में लपेटें ताकि वह flash में ही रहे, और लंबे चलने वाले स्केच में String class से बचें।
इसके प्रोजेक्ट: Arduino Uno R3
ECG trace on an OLED for learning (Arduino Uno + AD8232) — not medical
See the P-QRS-T wave of a real heartbeat — the biology textbook diagram, live.
2 h · Student projects
Bluetooth RC car controlled from your phone (Arduino Uno + HC-05)
Drive a robot car from your phone over Bluetooth.
3 h · Robotics
Classroom noise meter with a traffic-light LED bar (Arduino Uno + KY-038)
A green-yellow-red bar that shows how loud the class is — and reminds when it’s too loud.
1 h · Student projects
Classroom voting machine for class elections — an EVM model (Arduino Uno + 16x2 LCD)
One BALLOT press, one vote, one long beep — a class-election model of an EVM.
2 h · Student projects
Colour sorting machine with two servos (Arduino Uno + TCS34725)
Drop coloured beads in the tube — the machine sorts them into bins by itself.
4 h · Student projects
Contactless infrared thermometer (Arduino Uno + MLX90614 + OLED)
Point it at anything and read its surface temperature.
1 h · Student projects
Debate and elocution competition timer with warning lights (Arduino Uno)
Green, yellow, red and a bell — speakers see their time without anyone waving a card.
2 h · Student projects
Digital compass with a needle on an OLED (Arduino Uno + GY-271)
A needle that always points north — and the maths that makes it work.
1.5 h · Student projects
Digital dice on an 8×8 LED matrix (Arduino Uno + MAX7219)
Press the button — the dice tumbles and lands on 1 to 6.
45 min · Student projects
Dual-axis solar tracker with four LDRs and two servos (Arduino Uno)
A small panel that follows the sun across the sky on two servos.
3 h · Robotics
Fire-fighting robot model that finds and puts out a candle (Arduino Uno + flame sensors)
Seeks a candle flame, drives up to it and sprays until it’s out.
5 h · Student projects
Fire and smoke alarm with heat-rise detection (Arduino Uno + MQ-2 + DS18B20)
Smoke, high heat or a fast temperature rise — any one sets off the alarm.
1.5 h · India utility
LPG gas leak alarm with SMS alert (Arduino Uno + MQ-6)
MQ-6 sensor, loud buzzer and an SMS to your phone when LPG builds up.
2 h · India utility
GPS tracker that texts its location (Arduino Uno + NEO-6M + SIM800L)
Texts a Google Maps link with its location to your phone.
3 h · Student projects
GSM farm motor control by SMS (Arduino Uno + SIM800L)
SMS "MOTOR ON" from your phone; the farm motor starts through a contactor and stops itself after 2 hours.
4 h · India utility
Digital tachometer with a Hall sensor and magnet (Arduino Uno + A3144 + TM1637)
A magnet, a Hall sensor and an interrupt — RPM of any rotating thing on a 4-digit display.
1.5 h · Student projects
Inverse-square law of light experiment (Arduino Uno + BH1750 + VL53L0X)
Move a light sensor away from a lamp and watch the brightness fall as 1/d².
2 h · Student projects
Control a lamp with any TV remote (Arduino Uno)
Use any spare TV remote to switch a lamp on and off.
1 h · Home automation
Joystick-controlled robot arm with three servos (Arduino Uno)
A thumb joystick turns the base, lifts the arm and works the gripper.
2 h · Robotics
Keypad door lock with a servo latch (Arduino Uno)
Type the PIN to open the latch — three wrong tries lock it out.
1.5 h · Student projects
Snake game on an 8×8 LED matrix with a joystick (Arduino Uno + MAX7219)
The old Nokia snake on 64 LEDs — steer it with a joystick.
1.5 h · Student projects
Line follower robot with two IR sensors (Arduino Uno)
Two IR sensors keep it on a black line.
3 h · Robotics
Medicine reminder with a “taken” button (Arduino Uno + DS3231 + LCD)
Beeps at dose time until the “taken” button is pressed; shows what was missed.
1.5 h · Home automation
Milk collection weighing scale with price display (Arduino Uno + HX711)
Weighs milk to the gram and shows the ₹ amount to pay on a 16x2 LCD.
2.5 h · India utility
Mini sumo robot for college robo-fests (Arduino Uno + HC-SR04)
Finds the opponent, charges, and never drives out of the ring.
4 h · Robotics
Morse code trainer that decodes your keying (Arduino Uno + OLED)
Tap dots and dashes — the screen reads them back and scores you.
1 h · Student projects
Classroom seismograph with a scrolling OLED trace (Arduino Uno + MPU6050)
Thump the table and watch the shaking scroll across the screen like a real seismogram.
1.5 h · Student projects
Obstacle-avoiding robot with a scanning ultrasonic sensor (Arduino Uno)
Looks left and right, then turns towards the clearer path.
3 h · Robotics
Garage parking assistant with a ToF sensor and LED bar (Arduino Uno)
An LED bar that goes green → yellow → red as you park.
1 h · Student projects
Measure g with a simple pendulum and an IR photogate (Arduino Uno)
An IR gate times every swing — the LCD shows the period and g live.
2 h · Student projects
Two-gate photogate timer for speed and acceleration (Arduino Uno + IR sensors)
Two IR gates time a run to the microsecond — speed and acceleration on an LCD.
2 h · Student projects
Heart-rate display with a live pulse wave (Arduino Uno + Pulse Sensor + OLED)
See your own pulse as a wave on a tiny screen — and hear every heartbeat.
1 h · Student projects
Quiz buzzer system for 4 teams with lockout (Arduino Uno + TM1637 + WS2812B)
Four teams, one winner — the first press lights its colour and locks out the rest.
2 h · Student projects
Automatic railway level-crossing gate model (Arduino Uno + IR sensors + servo)
Trains from either side close the boom; it opens only after the last coach has gone.
3 h · Student projects
Rain alarm for drying clothes and grain (Arduino Uno + rain sensor)
Three loud beeps the moment the first drops hit the sensor.
45 min · Weather
Reaction timer game with a 4-digit display (Arduino Uno + TM1637)
Wait for GO, hit the button — how fast are you?
45 min · Student projects
RGB mood lamp with WS2812B LEDs and a rotary knob (Arduino Uno)
Turn the knob for colour, press it for breathe and rainbow modes.
1 h · Home automation
RS485 Modbus sensor reader for long cable runs (Arduino Uno + MAX485)
Talk to industrial Modbus sensors over hundreds of metres of twisted pair.
1.5 h · Network & ISP tools
Digital clock that keeps time through power cuts (Arduino Uno + DS3231)
A clock that keeps exact time even through power cuts.
45 min · Student projects
Sargam piano with 8 keys and a buzzer (Arduino Uno + TM1637)
Eight buttons, one buzzer — play Sa Re Ga Ma and see the physics of each note.
1.5 h · Student projects
Automatic school bell timer with RTC and LCD (Arduino Uno + DS3231)
Rings every period on time, skips Sundays, and keeps time through power cuts.
2 h · India utility
Shop shutter burglar alarm with SMS and call (Arduino Uno + SIM800L)
Shutter forced or motion inside at night → siren, SMS and a ringing phone.
3 h · India utility
Queue token number display for a clinic or shop (Arduino Uno + TM1637)
Press NEXT and the “now serving” number blinks and beeps — survives power cuts.
1 h · India utility
Simon memory game with colours and tones (Arduino Uno + WS2812B + passive buzzer)
Watch, listen, repeat — one more colour every round.
1.5 h · Student projects
Touch-free smart dustbin (Arduino Uno + HC-SR04 + servo)
Wave your hand and the lid opens — closes by itself after 3 seconds.
1.5 h · Student projects
Solar water heater display — how many buckets of hot water? (Arduino Uno + DS18B20)
Tank temperature and “~6 buckets at 40 °C” on an LCD inside the house.
2 h · Home automation
Measure the speed of sound with an ultrasonic sensor (Arduino Uno + HC-SR04)
Echo timing at known distances gives the speed of sound — with a line fit and theory check.
2 h · Student projects
Cyclone and storm pressure alert from a barometer (Arduino Uno + BMP180)
A barometer that watches the pressure trend and beeps before a storm arrives.
1 h · Weather
Overhead tank overflow alarm (Arduino Uno + float switch)
A float switch near the top of the tank and a buzzer — no more water on the terrace.
1 h · India utility
Teach-and-repeat robot arm that remembers 40 poses (Arduino Uno)
Show the arm a pick-and-place routine once, and it repeats it for ever.
4 h · Robotics
Tilt-controlled servo with an MPU-6050 (Arduino Uno)
Tilt the sensor and the servo follows your hand.
45 min · Robotics
Backup battery power-cut alarm with SMS (Arduino Uno + INA219 + SIM800L)
SMS when your POP’s 12 V backup battery starts discharging or runs low.
2.5 h · Network & ISP tools
Four-way traffic junction model with countdown and pedestrian button (Arduino Uno)
Four signal heads, a countdown and a pedestrian button — a real junction cycle in miniature.
3 h · Student projects
Ultrasonic radar scanner with an OLED radar screen (Arduino Uno)
A sweeping sonar that draws what it sees on a little radar screen.
1.5 h · Robotics
Automatic wet and dry waste segregator model (Arduino Uno + moisture plate + servo)
Drop waste on the flap — it tips into the wet or dry bin by itself and keeps count.
4 h · Student projects