Learning Resources

Python code for measuring distance using HC-SR04 sensor on Raspberry Pi with error handling.

import RPi.GPIO as GPIO
import time

TRIG = 17
ECHO = 27

def measure_distance():
    GPIO.output(TRIG, True)
    time.sleep(0.00001)
    GPIO.output(TRIG, False)
    
    while GPIO.input(ECHO)==0:
        start = time.time()
    while GPIO.input(ECHO)==1:
        stop = time.time()
    
    distance = (stop-start) * 17150
    return distance

ESP8266/ESP32 Arduino code for logging temperature to cloud with automatic WiFi reconnect.

#include 
#include 

void setup() {
  WiFi.begin(SSID, PASS);
  while(WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
}

void sendData(float temp) {
  HTTPClient http;
  String url = "http://api/log";
  http.POST(url + "?temp=" + temp);
}

Arduino C++ code for controlling DC motor speed using PWM and potentiometer feedback.

const int motorPin = 9;
const int potPin = A0;

void setup() {
  pinMode(motorPin, OUTPUT);
  pinMode(potPin, INPUT);
}

void loop() {
  int speed = map(analogRead(potPin),0,1023,0,255);
  analogWrite(motorPin, speed);
}

Complete Arduino library usage example for controlling SG90 servo with smooth movement.

#include 

Servo myServo;

void setup() {
  myServo.attach(9);
}

void loop() {
  for(int angle=0; angle<=180; angle++) {
    myServo.write(angle);
    delay(15);
  }
  delay(500);
}