TS9517TB-based blood oxygen acquisition module

This project is a blood oxygen acquisition verification module 1 based on the TS9517TB+STC8H1K08 microcontroller
. The project utilizes the high-performance domestically produced physiological signal integrated analog front-end TS9517 from Suzhou Kunyuan Microelectronics. The TS951X operates at a voltage of 2.5V~5.5V, with a typical quiescent current of 1.25mA. The current-frequency converter has a sensitivity of 100kHz/uA. The TS951X series integrates: a low-noise current-frequency converter (IF), an H-bridge light control unit, an analog (TS9514) or digital (TS9517) constant current dimming unit, and a hardware ambient light removal unit (TS9516, TS9517) with Kunyuan's patent. For specific chip characteristics, please refer to the manufacturer's promotional material: https://club.szlcsc.com/article/details_44183_1.html
2. This project uses the STC8H1K08+CH340N as the data acquisition, control, and communication transmission interface. Since the TS9517 output signal is a PWM waveform, the advanced PWM capture and matching function of the STC8H series is used to acquire the high and low level widths of the signal pulses. The level width is directly plotted as a curve, which is the blood oxygen volume waveform, also known as a pulse waveform. After data processing and calibration, it can be quantitatively measured.
3. In this design, the blood oxygen interface uses a standard D-SUB interface and a custom 3.5mm headphone jack interface, which is compatible with various disposable finger clip blood oxygen probes or monitor probes. 4. In this design, the STC8H1K08 and TS9517 can be powered by either AS1117-3.3 or VBUS 5V. Switching is done via a toggle switch, and the actual power supply voltage has minimal impact on the measurement results.
5. In this design, a push-button switch is used to control the small system's power-off and capacitor discharge, facilitating firmware updates by the ISP.
6. The operating waveform is shown below .