Monday, July 18, 2016

ESP8266 and PIR sensor (2)



On an earlier blog i posted an article about the ESP8266 and a 5 Volt PIR sensor.
I tested it powering with 3.3 volt.  It did work some times but not reliable. As i needed a PIR sensor in one of my projects (and i did not want to add 5 Volts) a search on internet did give this article using 'my' PIR motion detection sensor:
http://iot-playground.com/blog/2-uncategorised/74-esp8266-wifi-pir-motion-sensor-easyiot-cloud-rest-api
PIR sensor is power by 5V, but if we look at schematic we will see that is's 3.3V internally. Because ESP8266 is 3.3V, we can bypass PIR internal regulator.
Connection after regulator is available at JP1 pin 3. In our case we will connect 3.3V power supply to this point and not to 5V power supply.
See the picture below for my test and yes it will work if the you connect VCC (3.3V) to JP1 pin 3!
(In the picture Signal is connected to the pin labeled GPIO5, in reality this is GPIO4 )





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