Practical assignment 2, can't connect arduino to iPhone

Question

I've finished all the steps of the assignment, but connecting to the Arduino with bluetooth doesn't really work. I use the app BLE Terminal, as recommended. BLE-Nano is in the list, but when I press it, I can only see the date between [] and ASCII:

Then, when sending a t or h on my iPhone I get the message "Error. The connection has timed out unexpectedly" After a few tries it worked only once, but that was when the part "if char1=t" wasn't added to the code.

This is my code now:

    // DHT Temperature & Humidity Sensor
// Unified Sensor Library Example
// Written by Tony DiCola for Adafruit Industries
// Released under an MIT license.

// REQUIRES the following Arduino libraries:
// - DHT Sensor Library: https://github.com/adafruit/DHT-sensor-library
// - Adafruit Unified Sensor Lib: https://github.com/adafruit/Adafruit_Sensor

#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>
#include <NewPing.h>
#include <U8g2lib.h>

#include <SoftwareSerial.h>

SoftwareSerial bleserial(0,1); // RX, TX pins of BLE module of the Nano BLE

// display setup:
// software i2c:
//U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(7, 8, U8X8_PIN_NONE);
// hardware i2c:
U8X8_SSD1306_128X64_NONAME_HW_I2C display(U8X8_PIN_NONE);

char buf[10]; // text buffer; to be able to use draw2x2String to show the value

#define DHTPIN 2     // Digital pin connected to the DHT sensor 
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// Uncomment the type of sensor in use:
#define DHTTYPE    DHT11     // DHT 11
//#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

// See guide for details on sensor wiring and usage:
//   https://learn.adafruit.com/dht/overview

DHT_Unified dht(DHTPIN, DHTTYPE);

uint32_t delayMS;

char char1 = '-'; // first character of command to receive via chat

void setup() {
  bleserial.begin(9600);
  Serial.begin(9600);
  // Initialize device.
  dht.begin();
  Serial.println(F("DHTxx Unified Sensor Example"));
  // Print temperature sensor details.
  sensor_t sensor;
  dht.temperature().getSensor(&sensor);
  Serial.println(F("------------------------------------"));
  Serial.println(F("Temperature Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("°C"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("°C"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("°C"));
  Serial.println(F("------------------------------------"));
  // Print humidity sensor details.
  dht.humidity().getSensor(&sensor);
  Serial.println(F("Humidity Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("%"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("%"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("%"));
  Serial.println(F("------------------------------------"));
  // Set delay between sensor readings based on sensor details.
  delayMS = sensor.min_delay / 1000;

  // initialize display:
  display.begin();
  display.setPowerSave(0);

  display.setFont(u8x8_font_pxplusibmcgathin_f);
  display.drawString(0,0,"DHT sensor");
  display.draw2x2String(0,2,"Temp");
  display.drawString(0,7,"Humidity:");
}

void loop() {
  // Delay between measurements.
  delay(delayMS);
  // Get temperature event and print its value.
  sensors_event_t event;
  dht.temperature().getEvent(&event);
  if (isnan(event.temperature)) {
    Serial.println(F("Error reading temperature!"));
  }
  else {
    Serial.print(F("Temperature: "));
    Serial.print(event.temperature);
    Serial.println(F("°C"));
    // first character received was a 't'
    if( char1=='t' ) {
    dtostrf(event.temperature, 3, 1, buf); // print float like XXX.X
    display.draw2x2String(0,5,buf);
    }

  }
  // Get humidity event and print its value.
    dht.humidity().getEvent(&event);
    if (isnan(event.relative_humidity)) {
    Serial.println(F("Error reading humidity!"));
  }
  else {
    Serial.print(F("Humidity: "));
    Serial.print(event.relative_humidity);
    Serial.println(F("%"));
    if( char1=='h' ) {
    //first character received was a 'h'
    dtostrf(event.relative_humidity, 3, 1, buf); // print float like XXX.X
    display.drawString(10,7,buf);
    }

  }

  //if a sigbal is received, store it in char1
  if(bleserial.available()){
    char1 = bleserial.read(); // read first character of string received via BLE
  }


}

Answer 1

You can try to put this piece of code in the if statement.

Serial.print(F("Temperature: "));
Serial.print(event.temperature);
Serial.println(F("°C"));