This research is motivated by the lack of safety systems at densely populated road intersections. Road intersections in these areas often lack adequate attention in terms of security and safety, causing a high risk of accidents. Convex mirrors are the most widely used today, but these convex mirrors have disadvantages such as the need to keep the mirror clean at all times, very small
object reflections and lack of lighting can interfere with the function of this convex mirror. Researchers want to make a prototype warning system using ESP8266 as a control center, PIR SR602 sensor to detect motorists, Traffic Light to give warnings and DOTMAX7219 to add warnings in a text "Slow" "Stop" "Be careful", so it can be formulated in this study how the ability of the PIR SR602 sensor to read movement, test the effectiveness of the degree angle on the PIR SR602 sensor and how reliable the system logic is to regulate traffic lights and DOTMAX7219 based on data from the PIR SR602 sensor. Researchers use quantitative methods, with the steps of literature study, making tool design, making tools, making programs, testing tools and taking data. From the test results it can be concluded that the PIR SR602 sensor used has an average error of 2.38% and an accuracy rate of 97.62%, the PIR sensor can detect movement when the object is placed at a distance of 50 cm to 300 cm from the sensor, test the effectiveness of the PIR sensor angle at a distance of 50cm to 200cm with an angle of 45° to 120° the PIR sensor can detect movement, the ESP8266 logic system that has been programmed runs well when receiving commands and in standby.
Keywords: ESP8266, Traffic Light, Sensor PIR, three-way