Magic Messenger using 2 Magicbits-(ESP-32) Boards

// Code 2
// By MagicBit

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <esp_now.h>
#include <WiFi.h>

esp_now_peer_info_t peerInfo;

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Use the MAC of the other board below
uint8_t broadcastAddress[] = {0x78, 0x21, 0x84, 0x8D, 0xFF, 0x50}; 

int choose = 0;
int inputLine_y = 36;
int inputSpace_x = 7;
int R_count = 0;
int potValue;
char Msg[27]={' '};
char got[18];
char sent[18];
char elements[] = " ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
  memcpy(&got, incomingData, sizeof(got));
  Serial.print("Bytes received: ");
  Serial.println(len);
  Serial.print("Message: ");
  Serial.println(got);
  
  for (int i=0; i<18;++i) {
    display.fillRect(i*7,18, 7, 9, BLACK);
  }
  
  display.setCursor(1,19);   // input 
  display.setTextColor(WHITE);
  display.println(got);
  
}

void setup() {
  Serial.begin(115200);
//===============================

  WiFi.mode(WIFI_STA);

  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }
  
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;

    if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }
  esp_now_register_recv_cb(OnDataRecv);
  
//===============================
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(2000);
  display.clearDisplay();
  display.drawRect(0, 0, 128, 15, 1);
  display.setTextSize(1.5);
  display.setTextColor(WHITE);
  display.setCursor(20,4);
  display.print("MAGIC MESSENGER");
  display.drawLine(0,54,127,54,WHITE);
  display.display();

  display.drawLine(0,32 , 127, inputLine_y-4, WHITE);
  
  pinMode(34,INPUT);
  pinMode(35,INPUT);
  pinMode(39,INPUT);
}


void loop() {

  Serial.println(Msg);
  
  potValue = analogRead(39);
  int Lbutton = digitalRead(35);
  int Rbutton = digitalRead(34);

  if ((Rbutton==LOW)&&(choose==0)) {   // For Choose
    delay(300);
    Msg[R_count] = elements[map(potValue)];
    ++R_count;
  }

   if ((Rbutton==LOW)&&(choose==1)) {   // Delete all
    delay(300);
    R_count = 0;
    //strcpy(Msg,"");
    char Msg_tmp[27]={' '};
    strcpy(Msg,Msg_tmp);
    
    for (int i=0; i<18;++i) {
      display.fillRect(inputSpace_x * i, inputLine_y - 1, 7, 9, BLACK);
    }
  }

  if ((Rbutton==LOW)&&(choose==2)) {
    delay(300);
    strcpy(sent, Msg);
    esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &sent, sizeof(sent));
   
    if (result == ESP_OK) {
      Serial.println("Sent with success");
    }
    else {
      Serial.println("Error sending the data");
    }
  }

//==============================
  if (Lbutton == LOW){
    delay(300);
    choose++;
    
    if (choose > 2) {
      choose = 0;
    }
  }
  menu(choose);
//==============================

  display.fillRect(inputSpace_x * R_count, inputLine_y, 5, 7, BLACK); 
  display.fillRect(inputSpace_x * R_count, inputLine_y - 1, 7, 9, WHITE);
  display.setCursor(inputSpace_x * R_count + 1, inputLine_y);
  display.setTextColor(BLACK);  
  display.println(elements[map(potValue)]);

  for (int i=0; i<R_count;++i) {
    display.fillRect(inputSpace_x * i, inputLine_y - 1, 7, 9, BLACK);
    display.setCursor(inputSpace_x*i +1, inputLine_y);   // input 
    display.setTextColor(WHITE);
    display.println(Msg[i]);
  }
  display.display();
}


void menu(int pos) {

  switch (pos) {
    case 0 :{
    display.fillRect(48, 55, 45, 9, BLACK); //delete
    display.fillRect(98, 55, 30, 9, BLACK); //SEND
    
    display.fillRect(0, 55, 41, 9, WHITE);
    display.setTextSize(1);
    display.setTextColor(BLACK);
    display.setCursor(3, 56);
    display.println("Choose");

    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(51, 56);
    display.println("Delete");

    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(101, 56);
    display.println("Send");
  
    display.display();
    }
    break;

    case 1 :{
    display.fillRect(0, 55, 41, 9, BLACK); //choose
    display.fillRect(98, 55, 30, 9, BLACK); //SEND
    
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(3, 56);
    display.println("Choose");

    display.fillRect(48, 55, 41, 9, WHITE);
    display.setTextSize(1);
    display.setTextColor(BLACK);
    display.setCursor(51, 56);
    display.println("Delete");

    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(101, 56);
    display.println("Send");
  
    display.display();
    }
    break;

    case 2 :
    {
    display.fillRect(0, 55, 41, 9, BLACK); //choose
    display.fillRect(48, 55, 45, 9, BLACK); //delete
    
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(3, 56);
    display.println("Choose");

    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(51, 56);
    display.println("Delete");

    display.fillRect(98, 55, 30, 9, WHITE);
    display.setTextSize(1);
    display.setTextColor(BLACK);
    display.setCursor(101, 56);
    display.println("Send");
  
    display.display();
    }
    break;
  } 
}



int map(int potValue) {
  if (potValue == 4095) {
    return 36;
  } 
  else 
  {
  return int((potValue*37)/4095);
  }
}