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Freeform Esp32 Ios Notification Display

Made by phuzybuny / Displays / Notifications

About the project

A freeform desktop display for incoming iOS notifications. Utilizes female headers so that components can be reused and ESP-IDF FreeRTOS with Arduino to manage incoming BLE Notifications, display text, and backlight with timeout.

Project info

Difficulty: Moderate

Platforms: Arduino, Espressif

Estimated time: 3 hours

License: GNU General Public License, version 3 or later (GPL3+)

Items used in this project

Hardware components

	NodeMCU-32S Alternatively, any other equivalent ESP32 development board.	x 1
	I2C 1602 Arduino LCD Screen Optional: I2C module to reduce the number of pins but may compromise the rigidity of the freeform	x 1
	Breadboard Trim Potentiometer Used to adjust the contrast of the 1602 LCD display; 20k Ohm was used.	x 1
	Header Kit for Feather - 12-pin and 16-pin Female Header Set	x 1
	A2SHB N-Channel MOSFET Used to switch the display backlight.	x 1
	18AWG Tinned Copper Wire Used to make connections.	x 1
	M2 Screws	x 1
	Brass M2 Inserts	x 1

View all

Software apps and online services

ESP-IDP FreeRTOS

Hand tools and fabrication machines

	Needle nose Plier	x 1
	Flush cutter	x 1
	Soldering Iron	x 1
	Solder	x 1

Story

Problem

Having to retrieve my phone to review incoming notifications.

Solution

A desktop display connected wirelessly would allow for me to review notifications without the need to retrieve my phone.

Objectives

Connect to iPhone wirelessly: The ESP32 with its BLE capabilities was a good fit for this requirement. However, I was not experienced in BLE so a library would be needed to facilitate this requirement.

Display Text: I had a spare 1602 display available and its relatively large display (compared to SSD1306 OLEDs) was ideal for this application.

Backlight with Timeout: To make changes - wireless connectivity activity or incoming notifications - more noticeable, I wanted the backlight to turn on whenever a change occurred and then off after some time.

Angled Display: I wanted the display to reside on my desk at a convenient angle for viewing.

Achievements

Having recently reviewed Digi-Key's FreeRTOS series on YouTube, this was an ideal first project to try out a RTOS.

Connect to iPhone wirelessly : Thanks to the ESP32 ANCS Notifications library, it was relatively straightforward to connect to an iPhone for wireless BLE notifications.

Display Text: The Arduino Liquid Crystal library was used to display the notification text to the 1602 display.

Backlight with Timeout: Using a N-Channel MOSFET, the 1602 display backlight could be turned on then off after sometime with a single digital pin.

Angled Display: The freeform wiring allowed for the display to be angled as desired and would hold the ESP32 development board in proximity as a single package.

Photos

Above: 1602 display and tinned copper wire. M2 screws and brass inserts were screwed onto the display to make the frame more rigid.

Above: Female headers used to facilitate removal of components if needed.

Above: Potentiometer added for display contrast adjustment. ESP32 base also taking shape.

Above: The 'marriage' of the two freeform frames into a single piece. Still need to complete the remaining connections.

Above: Connections completed.

Above: Components needed.

Above: BLE Connected

Code

Notification LCD

#include "esp32notifications.h"
#include <LiquidCrystal.h>

// Only use 1 core
#if CONFIG_FREERTOS_UNICORE
  static const BaseType_t app_cpu = 0;
#else
  static const BaseType_t pro_cpu = 0;
  static const BaseType_t app_cpu = 1;
#endif


// Settings
static const uint8_t LCD_RS = 32;
static const uint8_t LCD_ENABLE = 33;
static const uint8_t LCD_D4 = 25;
static const uint8_t LCD_D5 = 26;
static const uint8_t LCD_D6 = 27;
static const uint8_t LCD_D7 = 14;
static const uint8_t BACKLIGHT = 13;
static const uint16_t BACKLIGHT_TIMEOUT_MS = 7000;  // milliseconds
static const char* BLE_NAME = "Notification Display";
static const uint8_t msg_queue_len = 5;


// Globals
static TaskHandle_t toggle_backlight_task = NULL;
static SemaphoreHandle_t sem_backlight;
BLENotifications notifications;
static QueueHandle_t msg_queue;


void toggleBacklight(void *parameters) {
  pinMode(BACKLIGHT, OUTPUT);
  
  while (1) {
    // Wait for notification
    xSemaphoreTake(sem_backlight, portMAX_DELAY);

    // Toggle LED Backlight
    digitalWrite(BACKLIGHT, HIGH);  // turn backlight ON
    vTaskDelay(BACKLIGHT_TIMEOUT_MS / portTICK_PERIOD_MS);
    digitalWrite(BACKLIGHT, LOW);  // turn backlight OFF
  }
}


void printLCD(void *parameters) {
  char lines[2][17];

  LiquidCrystal lcd(LCD_RS, LCD_ENABLE, LCD_D4, LCD_D5, LCD_D6, LCD_D7);  // rs, enable, d4, d5, d6, d7
  lcd.begin(16, 2);  // begin(columns, rows)

  while (1) {
    if (xQueueReceive(msg_queue, (void *)&lines, 0) == pdTRUE) {
      xSemaphoreGive(sem_backlight);

      lcd.clear();
      lcd.write(lines[0]);
      lcd.setCursor(0, 1);  // setCursor(column, row)
      lcd.write(lines[1]);
    }
  }
}


void onNotificationArrived(const ArduinoNotification * notification, const Notification * rawNotificationData) {
  char lines[2][17];
  notification->message.toCharArray(lines[0], 17);
  lines[0][16] = '\0';
  notification->message.substring(16).toCharArray(lines[1], 17);
  lines[1][16] = '\0';
  
  if (xQueueSend(msg_queue, (void *)&lines, 10) != pdTRUE) {
    Serial.println("ERROR: Could not put item in message queue.");
  }
}


void onBLEStateChange(BLENotifications::State state) {
  char lines[2][17];

  switch(state) {
    case BLENotifications::StateConnected:
      strncpy(lines[0], "BLE Connected", sizeof(char[17]));
      break;
    case BLENotifications::StateDisconnected:
      strncpy(lines[0], "BLE Disconnected", sizeof(char[17]));
      notifications.startAdvertising();
      break;
  }

  lines[1][0] = '\0';  // clear the second line

  if (xQueueSend(msg_queue, (void *)&lines, 10) != pdTRUE) {
    Serial.println("ERROR: Could not put item in message queue.");
  }
}


void setup(){

  // Create semaphores
  sem_backlight = xSemaphoreCreateBinary();  // Will be initialized to 0 by default

  // Create queues
  msg_queue = xQueueCreate(msg_queue_len, sizeof(char[2][17]));
  
  xTaskCreatePinnedToCore(
    toggleBacklight,        // Function to be called
    "Toggle backlight",     // Name of task
    1024,                   // Stack size (bytes in ESP32, words in FreeRTOS)
    NULL,                   // Parameter to pass to function
    1,                      // Task priority (0 to configMAX_PRIORITIES - 1)
    &toggle_backlight_task, // Task handle
    app_cpu                 // Run on one core for demo purposes (ESP32 only)
  );
  
  xTaskCreatePinnedToCore(
    printLCD,               // Function to be called
    "Print LCD",            // Name of task
    1024,                   // Stack size (bytes in ESP32, words in FreeRTOS)
    NULL,                   // Parameter to pass to function
    1,                      // Task priority (0 to configMAX_PRIORITIES - 1)
    NULL,                   // Task handle
    app_cpu                 // Run on one core for demo purposes (ESP32 only)
  );

  notifications.begin(BLE_NAME);
  notifications.setNotificationCallback(onNotificationArrived);
  notifications.setConnectionStateChangedCallback(onBLEStateChange);

  // Delete "setup" and "loop" tasks
  vTaskDelete(NULL);
}

void loop(){
}

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Freeform Esp32 Ios Notification Display

About the project

Project info