I. Description

Background

Perhaps most people still have limited knowledge of UWB. However, you must have heard of AirTag, which precisely uses UWB and combines with BLE FindMy to achieve the function of location tracking. Recently we have launched a brand new UWB module - BU03. With curiosity, we made this BUTag - Mjolnir.

Project Brief

BUTag is a UWB locator. With its precise ranging function, it can be accurately found using an iPhone. Its ultra-low standby power consumption means you don’t need to charge it for an entire year.

Its small size allows it to become a pendant on your keychain. It also looks good when hung on a bag.

You can see the distance to BUTag in real time on the mobile phone app. Some mobile phones can even see the direction of BUTag. 

If your bag or key cannot be found at home, it can be located through BUTag. If it is lost outdoors, satellite positioning can also be combined to find its specific location.

Note: Currently, it cannot achieve trajectory tracking yet because we haven’t developed the FindMy feature.

II. Hardware Design

The hardware of the entire project consists of two parts: the main board and the battery power supply board.

Mainboard

• UWB module：BU03——Click-to-buy
• Charging interface: Type-C_16p. (It is recommended to use 4P.)
• Charging chip: TP4057, SOT23-6 package.
• Charge current：400mA
• Indicator light：Side sticker RGB(common anode)
  • Charging：Blue
  • fully charged：Green

• MCU：nRF52832——Click-to-buy
• Battery：360mAh,Polymer lithium battery
• Antenna：Customized 2.4G PCB antenna