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Arduino ESP8266 Smart Motion Sensor using PIR and MQTT

Motivation

My son has a cat. And I've become very curious about the cat's feeding and toilet habits. Mainly I'm interested in how long does it take him to go to the toilet after eating as I've noticed a pattern: At first he goes to the kitchen, eats and then runs around the house wrecking havoc for some time and then goes to the toilet. So I'm curious whether this is his usual routine and moreover how many times during the day and night does he need to use his toilet. I might even build a collar for him to track the magnitude of his movements in the future :)

Building ESP8266 Weather station with BME280 (part II)

In a previous post I've described how to build a Weather Station based on ESP8266 chip and various breakout boards you can buy e.g. on Aliexpress. In this post, however I'll share with you how I built a standalone PCB boards containing all the required components.

Arduino Metal Detector using frequency counter and OLED display

There are a lot of forests in Lithuania which I like exploring on my bike. In the past a lot of Lithuanian resistance troops resided in those forests, so there is a big probability to stumble upon a stash of some kind. However that stash might as well be a grenade or a bomb of some kind, but nevertheless I always wanted to combine my motorcycle riding through the woods with treasure hunting and some time ago I decided to build a simple metal detector. Granted there are lots of metal detector designs, like BFO, VLFD, PI and so on (I'll briefly cover some of them in the theory section). Some of them I've tried in the past with various results and then during one boring evening of browsing the internet I stumbled upon this blog and decided to build this type of metal detector. The design is really simple - there is a simple oscillator circuit and a frequency counter. When the coil passes over or near various ferromagnetic or paramagnetic materials the frequency of the oscillator changes and based on this change you can decide where to dig. Moreover since the frequency counter can be implemented on any microcontroller you can analyse the frequency change in many different ways potentially enabling metal differentiation and even filter out frequency drift, that plagues other types of detectors.

Building ESP8266 Weather station with BME280 (part I)

Ever since I started playing around with ESP modules I wanted to measure weather conditions in multiple location at home, friends, etc. The best way to achieve that would be to build a station that gathers various environment parameters and publishes them somewhere. That is what I've done. The very first prototype was done using ESP-1 module, DHT-11 humidity sensor and BMP280 breakout board. The station publishes gathered data to a MQTT broker from where it can be further gathered and analysed.

ESP8266 Wheelie Using Mouse Sensor as a camera with Web interface

Wheelie finished