Rocket avionics ESP32 project | JLC PCB

// Pin 5 control with TX LED blink and additional functionality

#include <SD.h>
#include <Adafruit_MPL3115A2.h>

#define PIN_SPI_CS 4
#define BUTTON_PIN_START 8
#define BUTTON_PIN_RESET 9
#define LED_PIN 3
#define PIN_5 5

File myFile;
Adafruit_MPL3115A2 baro;
unsigned long loggingStartTime = 0;
const unsigned long loggingDuration = 180000; // 3 minutes in milliseconds
const unsigned long postLoggingFlashInterval = 3000; // 3 seconds
const unsigned long totalDuration = 300000; // 5 minutes in milliseconds
boolean loggingStarted = false;
boolean resetPressed = false;
boolean postLoggingFlashing = false;
boolean pin5TurnedOn = false;

void setup() {
  Serial.begin(9600);
  pinMode(BUTTON_PIN_START, INPUT);
  pinMode(BUTTON_PIN_RESET, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(PIN_5, OUTPUT);
  digitalWrite(BUTTON_PIN_START, LOW); // Enable internal pull-down resistor
  digitalWrite(BUTTON_PIN_RESET, LOW); // Enable internal pull-down resistor

  if (!SD.begin(PIN_SPI_CS)) {
    Serial.println(F("SD CARD FAILED, OR NOT PRESENT!"));
    while (1); // don't do anything more
  }

  Serial.println(F("SD CARD INITIALIZED."));

  if (!SD.exists("arduino.txt")) {
    Serial.println(F("arduino.txt doesn't exist. Creating arduino.txt file..."));
    myFile = SD.open("arduino.txt", FILE_WRITE);
    if (myFile) {
      myFile.close();
      Serial.println(F("Text written to arduino.txt file."));
    } else {
      Serial.println(F("Error opening arduino.txt file."));
    }
  } else {
    Serial.println(F("arduino.txt exists on SD Card."));
  }

  Serial.println("Adafruit_MPL3115A2 test!");

  if (!baro.begin()) {
    Serial.println("Could not find sensor. Check wiring.");
    while(1);
  }

  // use to set sea level pressure for the current location
  // this is needed for accurate altitude measurement
  // STD SLP = 1013.26 hPa
  baro.setSeaPressure(1013.26);
}

void loop() {
  unsigned long currentMillis = millis();

  if (digitalRead(BUTTON_PIN_START) == HIGH && !loggingStarted) {
    loggingStartTime = currentMillis;
    loggingStarted = true;
    Serial.println(F("Logging started."));
  }

  if (digitalRead(BUTTON_PIN_RESET) == HIGH && !resetPressed) {
    resetPressed = true;
    baro.setSeaPressure(baro.getPressure()); // Reset sea level pressure
    Serial.println(F("Sea level pressure reset."));
  } else if (resetPressed && digitalRead(BUTTON_PIN_RESET) == LOW) {
    resetPressed = false;
  }

  if (loggingStarted && (currentMillis - loggingStartTime) < loggingDuration) {
    flashLed(); // Flash LED during logging

    // Check if 8.1 seconds into the countdown
    if ((currentMillis - loggingStartTime) >= 9100 && !pin5TurnedOn) {
      // Turn on pin 5 for 0.5 second
      digitalWrite(PIN_5, HIGH);
      delay(500);
      digitalWrite(PIN_5, LOW);
      pin5TurnedOn = true;
      // Write "Parachute deployed" to SD card
      myFile = SD.open("arduino.txt", FILE_WRITE);
      if (myFile) {
        myFile.println("Parachute deployed");
        myFile.close();
        Serial.println(F("Parachute deployed. Written to arduino.txt file."));
      } else {
        Serial.println(F("Error opening arduino.txt file for writing."));
      }
    }

    float pressure = baro.getPressure();
    float altitude = baro.getAltitude();
    float temperature = baro.getTemperature();

    Serial.println("-----------------");
    Serial.print("pressure = "); Serial.print(pressure); Serial.println(" hPa");
    Serial.print("altitude = "); Serial.print(altitude); Serial.println(" m");
    Serial.print("temperature = "); Serial.print(temperature); Serial.println(" C");

    // Append the altitude information to the SD card
    myFile = SD.open("arduino.txt", FILE_WRITE);
    if (myFile) {
      myFile.println("-----------------");
      myFile.print("pressure = "); myFile.print(pressure); myFile.println(" hPa");
      myFile.print("altitude = "); myFile.print(altitude); myFile.println(" m");
      myFile.print("temperature = "); myFile.print(temperature); myFile.println(" C");
      myFile.close();
      Serial.println(F("Altitude information written to arduino.txt file."));
    } else {
      Serial.println(F("Error opening arduino.txt file for writing."));
    }
  } else if (loggingStarted) {
    loggingStarted = false;
    Serial.println(F("Logging stopped."));
    postLoggingFlashing = true; // Set the flag for post-logging flashing
  }

  if (postLoggingFlashing) {
    postLoggingFlash(); // Flash LED after logging

    if (currentMillis - loggingStartTime >= totalDuration) {
      // Turn off LED after 5 minutes
      digitalWrite(LED_PIN, LOW);
      postLoggingFlashing = false; // Reset the flag
      sendCompletionMessage(); // Send completion message to the SD card
    }
  }

  delay(250); // Adjust delay as needed
}

void flashLed() {
  static unsigned long previousMillis = 0;
  const unsigned long interval = 100; // Flashing interval in milliseconds

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Toggle the LED state
    if (digitalRead(LED_PIN) == HIGH) {
      digitalWrite(LED_PIN, LOW);
    } else {
      digitalWrite(LED_PIN, HIGH);
    }
  }
}

void postLoggingFlash() {
  static unsigned long previousMillis = 0;
  const unsigned long interval = postLoggingFlashInterval;

  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Toggle the LED state
    if (digitalRead(LED_PIN) == HIGH) {
      digitalWrite(LED_PIN, LOW);
    } else {
      digitalWrite(LED_PIN, HIGH);
    }
  }
}

void sendCompletionMessage() {
  myFile = SD.open("arduino.txt", FILE_WRITE);
  if (myFile) {
    myFile.println("Flight has completed");
    myFile.close();
    Serial.println(F("Completion message written to arduino.txt file."));
  } else {
    Serial.println(F("Error opening arduino.txt file for writing completion message."));
  }
}