Build your own Airtag for Asset Tracking

Published  August 7, 2024   
S Staff
Author



Overview

We all know that there is nothing more infuriating than forgetting where we placed something important or misplaced things. Losing your keys, wallet, or other valuable items can be a frustrating experience. Apple recognised this common problem and introduced the AirTag, a small, Bluetooth-enabled device that helps you keep track of your belongings. By attaching an AirTag to your items, you can easily locate them using the "Find My" app on your iPhone. The AirTag sends a secure Bluetooth signal that nearby devices in the Find My network can detect, allowing you to see the item's location on a map. Inspired by the functionality and usefulness of Apple's AirTag, we created a DIY solution that brings similar benefits with a personal touch. This project involves creating your own Bluetooth Low Energy (BLE) air tag/key finder that will help you keep your important things safe. 

The heart of this project is an MDBT50Q-1MV2 BLE  module from Raytac featuring an nRF52840, an ultra low power BLE SoC from Nordic with a 32-bit ARM Cortex-M4 core running at 64MHz. An ADXL345 3-axis accelerometer from Analog devices is also included in the circuit to detect movement. Multiple LEDs and an active buzzer are provided for visual and audible indications. The whole circuit is powered by a 3V CR2032 lithium battery. The key finder function can be used to find the Airtag which the Airtag will output a loud alarm along with LED indications, which makes it easier to find it in both bright and dark environments. With loss prevention mode enabled the Airtag will sound the Alarm and LED indications as soon as the Airtag is disconnected from the smartphone.

Code File

PCB Gerber File

Components Required

Value Manufacturer Digikey Part Number Datasheet Link    Quantity
CR2032 Adam Tech 2057-BH-74B-5-ND datasheet icon

  Datasheet

1
SMT-0540-S-R PUI Audio 668-1060-1-ND datasheet icon

  Datasheet

1
7pF Murata Electronics 490-5878-1-ND datasheet icon

  Datasheet

2
10uF Manufacturer 490-GRM155R60J106ME05DCT-ND datasheet icon

  Datasheet

4
LED Red Harvatek Corporation 3147-B1911USD-20D000114U1930CT-ND datasheet icon

  Datasheet

1
LED Blue Harvatek Corporation 3147-B1911NB--20C005314U1930CT-ND datasheet icon

  Datasheet

1
1N4148WS Diotec Semiconductor 4878-1N4148WSCT-ND datasheet icon

  Datasheet

1
ADXL345BCCZ Analog Devices Inc. 505-ADXL345BCCZ-ND datasheet icon

  Datasheet

1
NFC ANT Taoglas Limited 931-FXC.16.A-ND datasheet icon

  Datasheet

1
S8050 Micro Commercial Co MMSS8050-L-TPMSCT-ND datasheet icon

  Datasheet

1
1k Panasonic Electronic Components P1.00KLCT-ND datasheet icon

  Datasheet

3
27R Panasonic Electronic Components P27.0LCT-ND datasheet icon

  Datasheet

2
10k Panasonic Electronic Components P10.0KLCT-ND datasheet icon

  Datasheet

2
MDBT50Q-1MV2 Seeed Technology Co., Ltd 1597-1678-ND datasheet icon

  Datasheet

1
32.768KHz Abracon LLC 535-9543-1-ND datasheet icon

  Datasheet

1