Circuit Documentation

Summary

This circuit is designed to interface a Wemos D1 Mini microcontroller with a DHT11 Humidity and Temperature Sensor, a 0.96" OLED display, and an HW-040 Rotary Encoder. The purpose of the circuit is to read temperature and humidity data from the DHT11 sensor, display this information along with a menu on the OLED screen, and use the rotary encoder for navigating through the menu options.

Component List

Wemos D1 Mini

• Description: A compact microcontroller based on the ESP8266 WiFi-enabled microcontroller.
• Pins: RST, A0, D0, D5, D6, D7, D8, 3V3, 5V, G, D4, D3, D2, D1, RX, TX

DHT11 Humidity and Temperature Sensor

• Description: A basic, low-cost digital temperature and humidity sensor.
• Pins: VDD, DATA, NULL, GND

0.96" OLED

• Description: A small OLED display for visual output.
• Pins: GND, VDD, SCK, SDA

HW-040 Rotary Encoder

• Description: An input device that provides rotary input and has an integrated push-button.
• Pins: GND, +, SW, DT, CLK

Wiring Details

Wemos D1 Mini

• D5: Connected to CLK pin of HW-040 Rotary Encoder
• D6: Connected to DT pin of HW-040 Rotary Encoder
• D7: Connected to SW pin of HW-040 Rotary Encoder
• 3V3: Connected to VDD pins of DHT11 Sensor, 0.96" OLED, and + pin of HW-040 Rotary Encoder
• G: Connected to GND pins of DHT11 Sensor, 0.96" OLED, and GND pin of HW-040 Rotary Encoder
• D4: Connected to DATA pin of DHT11 Sensor
• D2: Connected to SDA pin of 0.96" OLED
• D1: Connected to SCK pin of 0.96" OLED

DHT11 Humidity and Temperature Sensor

• VDD: Connected to 3V3 pin of Wemos D1 Mini
• DATA: Connected to D4 pin of Wemos D1 Mini
• GND: Connected to G pin of Wemos D1 Mini

0.96" OLED

• GND: Connected to G pin of Wemos D1 Mini
• VDD: Connected to 3V3 pin of Wemos D1 Mini
• SCK: Connected to D1 pin of Wemos D1 Mini
• SDA: Connected to D2 pin of Wemos D1 Mini

HW-040 Rotary Encoder

• GND: Connected to G pin of Wemos D1 Mini
• +: Connected to 3V3 pin of Wemos D1 Mini
• SW: Connected to D7 pin of Wemos D1 Mini
• DT: Connected to D6 pin of Wemos D1 Mini
• CLK: Connected to D5 pin of Wemos D1 Mini

Documented Code

/*
 * This Arduino Sketch is designed for a Wemos D1 Mini microcontroller. 
 * It interfaces with a DHT11 sensor to read temperature and humidity, 
 * a 0.96" OLED display to show a menu with these readings and other 
 * options, and an HW-040 Rotary Encoder for menu navigation.
 */

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define DHTPIN D4
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

#define CLK D5
#define DT D6
#define SW D7

int menuIndex = 0;
const int menuItems = 3;

void setup() {
  pinMode(CLK, INPUT);
  pinMode(DT, INPUT);
  pinMode(SW, INPUT_PULLUP);
  dht.begin();
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print("Initializing...");
  display.display();
  delay(1000);
}

void loop() {
  static int lastClkState = HIGH;
  int clkState = digitalRead(CLK);
  if (clkState != lastClkState) {
    if (digitalRead(DT) != clkState) {
      menuIndex = (menuIndex + 1) % menuItems;
    } else {
      menuIndex = (menuIndex - 1 + menuItems) % menuItems;
    }
    lastClkState = clkState;
    displayMenu();
  }
  if (digitalRead(SW) == LOW) {
    executeMenuAction();
    delay(200);
  }
}

void displayMenu() {
  display.clearDisplay();
  display.setCursor(0,0);
  switch(menuIndex) {
    case 0:
      display.print("1. Show Temp & Humidity");
      break;
    case 1:
      display.print("2. Option 2");
      break;
    case 2:
      display.print("3. Option 3");
      break;
  }
  display.display();
}

void executeMenuAction() {
  switch(menuIndex) {
    case 0:
      displayTempHumidity();
      break;
    case 1:
      // Add action for Option 2
      break;
    case 2:
      // Add action for Option 3
      break;
  }
}

void displayTempHumidity() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  display.clearDisplay();
  display.setCursor(0,0);
  display.print("Temp: ");
  display.print(t);
  display.print(" C");
  display.setCursor(0,10);
  display.print("Humidity: ");
  display.print(h);
  display.print(" %");
  display.display();
  delay(2000);
  displayMenu();
}

This code is responsible for initializing the components, reading sensor data, handling the rotary encoder input, updating the OLED display, and executing actions based on the menu selection.