System Model Structure of Bluetooth Low Energy tws earbuds facebook

The system designed in this paper is mainly divided into two parts: intelligent hardware and application software for BLE wireless communication technology and Android client. The hardware is divided into a microcontroller unit (MCU) that runs an embedded real-time operating system (free real time operating system FreerTOS) (V823.USA) inside, and a general file system (fileallocation table file systemFATFS) module is transplanted. That is, the file allocation table (fileallocation tableFAT) is a common file system module for small embedded systems, which is used to manage files and store data; secondly, it integrates various hardware function modules - pedometer (step) module, heart rate monitoring (pulsesensor) Module, attitude sensor and magnetoresistive sensor module, flash memory (Micro-SD) card module invented by SanDisk, power management module, liquid crystal display (liquid crystal display LCD) and touch color screen module, real-time clock (real-timeclockRTC) ) backup battery module mobile network communication module and so on.bjbjaudio.com   <a style="opacity:0.0;color:#ffffff">tws earbuds facebook</a>   <a style="opacity:0.0;color:#ffffff">tws earbuds facebook</a>

It should be noted that the accurate design of the system circuit schematic diagram and the reasonable wiring of the printed circuit board will greatly improve the stability of the equipment and the power consumption and other indicators. This paper focuses on this problem and standardizes the design of the smart watch system to improve the system stability.bjbjaudio.com      <a style="opacity:0.0;color:#ffffff">tws earbuds facebook</a>        <a style="opacity:0.0;color:#ffffff">tws earbuds facebook</a>

System software design
The development platform of this paper selects FreeRTOS, a real-time operating system that manages multitasking, which is a completely free and very mature open source operating system. In this paper, considering that the main control MCU does not expand the external memory chip, and the internal memory of the chip to store the execution code is quite limited, it chooses FreeRTOS, which compiles and generates a very small amount of code. At the same time, in order to improve the running speed and solve the problem of internal storage , this paper also arranges the data fusion and task scheduling algorithm to be executed on the server side. The Android device side only does real-time data storage, which effectively solves the problem of limited computing power and capacity of mobile devices. difficult problem. bjbjaudio.com

Client application data synchronization method
The client MCU of this system is connected with the sensor module through the universal asynchronous receiver/transmitter (universalasvnchronousreceiver/transmitterUART) serial port. After the sensor module is started, the MCU will automatically send the broadcast code, and the client application (application programAPP ) will search for the broadcast code and connect to it. After success, the MCU will communicate with the mobile terminal in two directions through the serial port, and the sensor data will be pushed to the MCU file. After the MCU processes the sensor data Accordingly, the client APP starts running again. First scan the BLE module nRF51822 (NordicInc.. Denmark) and connect to it, then the main control MCU packs the data in a certain format and sends it to the Bluetooth module. After receiving, the Bluetooth module encapsulates the data into encrypted wireless signals according to the general specification (genericattributesGATT) in the BLE protocol and transmits it. The B luetooth device in the connected state will also parse the received data packets according to the GATT protocol. Restore the original Data, provide client APP use.bjbjaudio.com

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