本研究主要提出ZigBee無線通訊網路結合語音、三軸加速感測器用於老人求救裝置、自行車隊的溝通,三軸加速感測器可感測跌倒中瞬間急跳度,再配合語音通話說明現場狀況。 本研究分為兩部份,第一部分為Zigbee無線語音傳輸,利用JN-5139中的SPI、I2C、GPIO連接WM8510,具有低功耗、低成本、低延遲、可靠性的資料傳輸,其傳輸頻段為2.4GHz,具有128-bit AES資料保密功能,傳輸模式有單工、半雙工、全雙工,可依需求使用不同的傳輸模式。 第二部份為跌倒偵測,利用JN-5139模組和ADXL345三軸加速度模組配合模糊理論推論是否跌倒,先計算加速度急跳度並計算加速偏移強度,假如加速強度達到一個臨界值時則做模糊理論判斷,達到省電的效果。
In this thesis, the application of ZigBee wireless network is proposed. It combines the audio transmission system and three-axis acceleration sensor device. This system is applied to help the elderly, and communication of the cycling team. The three-axis accelerometer sensor can detect the motion condition and the audio device is used to transmit the field situation. This research is divided into two parts. The first part is wireless audio communication using the JN-5139 module and audio IC WM8510. It provides low power, low cost, low latency, and high reliability of data transmission. The transmission band is at 2.4GHz with 128-bit AES data security features. It includes three kinds of transmission mode, (1) simplex, (2) half duplex, and (3) full-duplex. The second part is the fall detection system. It uses the JN-5139 module and the three-axis accelerometer module ADXL345.The fuzzy theory is designed to infer falling behavior, calculate the jerk and the acceleration strength. When the strength reaches the threshold value, the fuzzy method is applied to make the judgment. It is shown that the proposed system can indeed detect the fall situation and accomplish the audio communication by using the wireless sensor networking.