Tiny Pressure Monitor using NPA201 Sensors
Created: Sep 27, 2016
No description available.
This project is a pressure monitor circuit. It is built with the NPA201 pressure sensor from Amphenol. The device is an absolute pressure sensor with a digital output that can be interfaced through I2C. This sensor is very tiny, about 2.0 x 2.5 x 1.0mm in size, very suitable for compact, portable and battery-powered applications.
This tiny pressure monitor is simple in construction. It is comprised of the NPA201 pressure sensor, a microcontroller (MCU) and an OLED display. The NPA201 employs a MEMS pressure sensor with an internal signal conditioning to provide accurate pressure measurements that ranges from 260 to 1260mBar. A digital compensation of the signal offset, sensitivity, temperature and non-linearity are also accomplished through an 18bit internal digital signal processor running a correction algorithm. The measured and corrected bridge values are provided at the digital output pins, through an I2C interface. The I2C bus, which connects the sensor to the MCU, utilizes a FET as a voltage level translator since the sensor is powered by a 3.3V and the MCU is powered by a 5V supply. The OLED used is chosen to be small in size to maintain the compact design of the project. The OLED is a 128X64 display that is about 1” in diameter. The OLED display is connected to the MCU through the SPI bus. A 6V battery powers the circuit going through LDO voltage regulators to provide the desired voltage levels of 3.3V and 5V. This circuit despite of being small can be very reliable and can give an absolute accuracy of +/-0.2mBar.
Pressure monitoring is made simple nowadays because of the available technology yet the data that it gathers is valuable and is used in vast applications by different industries. Some applications where the NPA201 is widely used are in mobile devices, navigation, weather station equipment, hard drives, and on wearable technologies.