1. Introduction Barometric pressure measurement has wide applications in instruments, medical and health equipment, barometers, altimeters, and other industrial equipment. Selecting a high-speed, high-precision sensor is crucial for practical engineering applications. Based on our research group's tasks, this paper mainly introduces the SCP1000-D01, a high-precision, high-resolution, and low-power digital barometric pressure sensor. This device can be used in the manufacture of barometers for micro or small UAVs, is easy to operate, and portable. 2. Performance Characteristics and Pin Functions The SCP1000-D01 is a revolutionary product from the Finnish company VTI. This absolute pressure sensor, based on D-MEMS technology, achieves sub-meter resolution and 1-meter accuracy under normal conditions, making it suitable for many commercial applications. The SCP1000-D01 offers four measurement modes: high precision, high speed, low power consumption, and ultra-low power consumption. Users can select the measurement mode according to their needs. This system is designed for use on a UAV, where high speed is required; therefore, the high-speed mode was chosen. The communication interface uses an SPI interface. For barometric pressure sensor applications, high accuracy is paramount to meet practical requirements. The SCP1000-D01 boasts an absolute pressure accuracy of -100 Pa to +100 Pa (approximately -8.5 m to +8.5 m) and a temperature accuracy of 1°C to 2°C. This accuracy is currently the highest among miniature barometric pressure sensors. The SCP1000-D01 integrates an A/D converter, facilitating user development and design while reducing system weight and circuit complexity, meeting current sensor usage requirements. In high-precision mode, the resolution is 1.5 Pa to 6 Pa (approximately 0.1 m to 0.4 m); in ultra-low power mode, the resolution is 2 Pa to 15 Pa (approximately 0.2 m to 1.3 m). Its temperature resolution is 0.2°C to 0.5°C. The SCP1000-D01 employs a surface-mount design and ASIC packaging, resulting in extremely low power consumption. Its operating voltage is 2.4 V to 3.3 V, and the maximum current is only 50 μA, which is negligible. The SCP1000-D01 has a circular structure with a diameter of only 6 mm and a height of only 1.7 mm. The SCP1000-D01 has 16 pins: 7 I/O pins and 9 power pins. Its pin structure and shape are shown in Figure 1, with the sensor chip header at the top center. The functions of the I/O (SPI interface) pins are shown in Table 1. TRIG is an externally triggered low-power mode, specifically activated by a falling edge signal. If not used, this pin is connected to DVSS. DRDY is the output interrupt signal, used to notify the user that temperature and pressure values ​​have been measured and are ready to be read. A high level on the PD pin allows the SCP1000-D01 to maintain low-power mode for an extended period. The SCK, MOSI, MISO, and CSB pins form the data communication line. 3. Internal Structure and Working Principle The SCP1000-D01 pressure sensor includes a pressure sensing head and a special-purpose integrated circuit. The SCP1000-D01 pressure sensor internally contains an A/D converter and registers for storing air pressure and temperature values, as shown in Figure 2. After starting the SCP1000-D01, linearization and status detection are performed first, followed by selecting the measurement mode. 3.1 Mode Selection As mentioned above, the SCP1000-D01 has four measurement modes. High-precision, high-speed, and ultra-low-power modes operate continuously, while low-power mode operates in a triggered manner. That is, to start low-power mode measurement, a rising edge signal needs to be given to TRIG or 0x0C needs to be written to the OPERATION register; while high-precision, high-speed, and ultra-low-power modes are started by writing 0x0A, 0x09, and 0x0B to the OPERATION register, respectively. The timing diagram for continuous measurement mode is shown in Figure 3, and the timing diagram for triggered measurement mode is shown in Figure 4. 3.2 Data Reading After selecting the measurement mode, the measured data needs to be read for use. A signal on the DRDY pin indicates that measurement data can be read. Temperature data is stored in registers [13:0] of the TEMPOUT register, where bit 13 is the sign bit. Converting its binary data to the corresponding decimal value yields the temperature value using the following formula: Pressure data is stored in registers [2:0] of DATARD8 and [15:0] of DATARD16. These two data points are concatenated to form a 19-bit binary value. Converting this to decimal yields the pressure value using the following formula. 3.3 Register Address Description The SCP1000-D01 integrates multiple registers to store corresponding measurement data. The addresses of important registers are listed in Table 2. 4 Typical Applications The circuit diagram of the barometer system designed based on the SCP1000-D01 and AT89S51 microcontroller is shown in Figure 5. In engineering applications, the MAX232E is used to convert between the microcontroller's TTL level and the host computer's RS232 level, transmitting the pressure information to the host computer. The specific circuit is shown in Figure 6. 5. Conclusion This paper introduces the advantages and applications of the SCP1000-D01 barometric pressure sensor from VTI, Finland. With its high precision, high resolution, high integration, low power consumption, small size, and light weight, the SCP1000-D01 possesses extremely high research and application value.