Abstract
Previously, we have developed a human monitoring system, which used 8051 microcontroller. The system has a 3-axis acceleration sensor, a pressure sensor, a humidity sensor, and an electrocardiogram (ECG) circuit. This paper reports the newly developed system by using PSoC (Programmable System-on-Chip), which is a microcontroller with some analog blocks in a single chip. The ECG and the acceleration are sampled at 125 Hz, the others are at 1 Hz by the PSoC. The sampled data are stored on the micro SD card or Static RAM (SRAM), transmitted by a Bluetooth module or USB interface to a PC. The multipurpose I/O pins for addition of some sensors are designed in the system. The multipurpose I/O pins are utilized to control and communicate with an infrared temperature sensor. The system was designed and fabricated by 4-layer printed circuit board (PCB). In comparison with the previous work, the system size was reduced from 85×48×15 mm3 to 50×50×15 mm3, the power consumption without Bluetooth communication was reduced from 45.0 mA to 24.6 mA when the power supply voltage is 3.3 V and the master clock is 48 MHz.
