#include <dht.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
dht DHT;
#define DHT22_PIN 5
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
// Initialize the OLED display with I2C address 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
struct {
uint32_t total;
uint32_t ok;
uint32_t crc_error;
uint32_t time_out;
uint32_t connect;
uint32_t ack_l;
uint32_t ack_h;
uint32_t unknown;
} stat = { 0, 0, 0, 0, 0, 0, 0, 0};
void setup() {
Serial.begin(115200);
Serial.println("dht22_test.ino");
Serial.print("LIBRARY VERSION: ");
Serial.println(DHT_LIB_VERSION);
Serial.println();
// Initialize the OLED display
if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
display.setCursor(0, 0);
display.print("Initializing DHT22");
display.display();
delay(2000);
}
void loop() {
uint32_t start = micros();
int chk = DHT.read22(DHT22_PIN);
uint32_t stop = micros();
stat.total++;
String statusMessage;
switch (chk) {
case DHTLIB_OK:
stat.ok++;
statusMessage = "OK";
break;
case DHTLIB_ERROR_CHECKSUM:
stat.crc_error++;
statusMessage = "Checksum error";
break;
case DHTLIB_ERROR_TIMEOUT:
stat.time_out++;
statusMessage = "Time out error";
break;
case DHTLIB_ERROR_CONNECT:
stat.connect++;
statusMessage = "Connect error";
break;
case DHTLIB_ERROR_ACK_L:
stat.ack_l++;
statusMessage = "Ack Low error";
break;
case DHTLIB_ERROR_ACK_H:
stat.ack_h++;
statusMessage = "Ack High error";
break;
default:
stat.unknown++;
statusMessage = "Unknown error";
break;
}
// Convert Celsius to Fahrenheit
float tempF = DHT.temperature * 9.0 / 5.0 + 32.0;
// Print the results to Serial
Serial.print("DHT22, \t");
Serial.print(statusMessage);
Serial.print(",\t");
Serial.print(DHT.humidity, 1);
Serial.print(",\t");
Serial.print(DHT.temperature, 1);
Serial.print(" C, ");
Serial.print(tempF, 1);
Serial.print(" F, ");
Serial.print(stop - start);
Serial.println(" us");
// Display results on OLED
display.clearDisplay();
display.setCursor(0, 0);
display.print("Status: ");
display.println(statusMessage);
display.print("Humidity: ");
display.print(DHT.humidity, 1);
display.println(" %");
display.print("Temp: ");
display.print(DHT.temperature, 1);
display.println(" C");
display.print(" ");
display.print(tempF, 1);
display.println(" F");
display.print("Time: ");
display.print(stop - start);
display.println(" us");
display.display();
delay(2000);
}