Photoplethysmography (PPG) signals are signals obtained as a result of optically measuring volumetric changes in capillaries. Volumetric changes in capillaries also depend on the work of heart. According to recent researches, it has been seen that PPG signals contain a lot of information about the physiological and biological state of related person. Most of these studies are based on the analysis of characteristics and waveforms of PPG signals obtained with a single wavelength in time and frequency domains. In this study, 10 minutes of data was taken from the left index finger of a 24-year-old male, which was positioned horizontally using a MAX30100 sensor and Raspberry Pi 4 microcomputer. Experiments are carried out in the fully resting state of a male volunteer in outdoors and stressful environments. While the MAX30100 sensor shows the heartbeat on the screen, it also gives PPG signal data, which is a single wavelength, into a .csv file as received data. In these cases, five different time domain parameters of received PPG signals are extracted. When the results are interpreted, it is seen that all results are meaningful and consistent.