Desenvolvimento de um enlace de comunicação e alimentação para um sistema de telemetria com unidade sensora microcontrolada

Abstract

The present paper describes the development of a data communication and power link applied to a telemetry system formed by a microcontrolled sensor unit and a reading unit. Via an inductive link developed, the reading unit is able to provide power and establish data communication with the sensor unit that has a supply circuit, a microcontroller, and a sensor. The inductive link consists of three coils, two of them are reading units and one is a sensor unit. A signal generator and a driver in the reading drive allow energy to be sent to the sensor unit via magnetic field generated by the coupling of the link coils. The sensor unit sends the digital data to the reading unit by using a modulator LSK. A demodulator located in the drive recovers the data that is received and processed by a microcontroller, which provides the measurement result to a computer, by means of a serial communication between the computer and the microcontroller. The obtained results show that the sensor unit operates at a coupling distance of up to 21 mm between the coils of the reading and sensing units to a communication rate of 9600 bps, whereas the maximum data communication rate achieved was 38400 bps at 10 mm of distance. It is believed that the developed inductive link, through a miniaturization process, can be used in biotelemetry systems for assessing biological phenomena or physiological events in the human body.