by kinasmith @ instructables.com:
This is a tutorial on building a Compost Temperature monitoring system. It details how to build a web connected wireless sensor network and shows one possible way it could be constructed.
A Medium level of knowledge and skills are required. Basic knowledge of soldering and breadboarding will be very useful. I will assume that you know enough Arduino code to understand what a Function is, how a Library is useful, and why Serial Communication is important. And you will need to know enough electronics to understand what I mean with terms like Voltage, Current, Resistance, etc. A (very) basic knowledge of how radio works would also be useful for understanding the concepts, but not essential for following along. This is not advanced by any means and I will attempt to always reference materials that will cover these concepts in greater detail.
Compost Sensor – [Link]
Rui JC writes:
This circuit is a small “on-board” temperature recorder for RC models.
For those who practice this hobby know that the engine temperature is very important, not only for performance but also to ensure the smooth operation and durability of the engine.
It records the motor temperature of my helicopter in flight 2 times per second and stores it in memory.
Helicopter Temperature Logger – [Link]
by codebender_cc @ instructables.com:
The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino.
The MQ-2 Gas Sensor module is useful for gas leakage detecting in home and industry. It can detect LPG, i-butane, propane, methane ,alcohol, hydrogen and smoke.
Some modules have a built-in variable resistor to adjust the sensitivity of the sensor.
How to use MQ2 Gas Sensor – Arduino Tutorial – [Link]
Aistin is the product family for creative Internet-of-Things experiences, with Arduino conformance.
The Internet of Things has a different meaning for different people. For some, it means monitoring room temperatures from a mobile phone, whereas for other, it is controlling garden lighting from a laptop computer. For sports-minded people, it might mean logging their heart rate in real-time to a cloud service. Is there a common denominator between this wide range of different applications?
Our answer is Aistin. Instead of functionally limited ready-made IoT-sets, or flexible but unpractical self-wired desktop hassles, we wanted to inspire people to create new mobile products by providing the best that can be achieved with current technology:
iProtoXi Aistin: Multi-Modular Sensor Platform – [Link]
by PowerBot @ instructables.com:
Hello, everyone !!! Today I’m going to show you how to make thermometer with Arduino and LM35 termperature sensor, builded on bread board and conected together with jumpers (bunch of cables :D).
Arduino Thermometer With LM35 – [Link]
The Wifi Arduino 85 is a small board with ESP8266 -01 module, Attiny85 micro controller and a relay. It Also has and additional header for connecting an external relay or to connect sensors like PIR, IR etc depending on your application. If you are a tinkerer you will also be able to connect a HC-05/06 Bluetooth module and convert this board to a Bluetooth Arduino 85 board.
Smart Plug with Esp8266, Attiny 85 & PIR Sensor – [Link]
by Samuel_Alexander @ instructables.com:
In this project we are going to learn how to use the HC-SR04 PING))) ultrasonic sensor to measure distance. This sensor is also often used on robots to detect obstacles.
Simple Distance Measuring Device – [Link]
by dkroeske @ github.com:
A cheap 555 timer chip acting as Schmitt trigger combined with a phototransistor or LDR is taped to the ‘flashing light’ or ‘pulsing magnet’ on the electricity meter. The output of the 555 timer chip is connected to one of the GPIO pins on the Raspberry Pi. A Python script (executing in the background) recording 555 events is calculating actual energy usage [e.g. Watt] every time the 555 is signaling and stores epochs in an SQLite3 database. From this, another Python script (executed from e.g. cron) generates all kinds of energy usage information (e.g. kWh or kWday or whatever). Using Node.js (running on the same Pi) all data is ‘RESTified’ enabling spreading out to the W3. To maintain privacy JSON web tokens are required every time the service is queried. Oh, and there is also a Pimatic plugin available (here)
Emon-server – 555 Timer as power usage sensor – [Link]
The MMA955xL platform as a sensor hub is an intelligent sensing hub with built-in accelerometer, signal conditioning, and data conversion with 32-bit programmable microcontroller and temperature sensor. In addition, it has a second I2C bus and one external analog input, which can be monitored using the on-chip Analog-to-Digital (ADC). This unique blend transforms Freescale’s MMA955xL into an intelligent, high precision, motion-sensing platform able to manage multiple sensor inputs.
The combination of low power consumption and powerful features means that the MMA955xL platform can effectively operate as a power controller for handheld units such as industrial scanners, Personal Digital Assistant (PDA), and games. The host platform can put itself to sleep with confidence that the MMA955xL device will issue a wake request should any external event require its attention. The MMA955xL device is programmed and configured with the codewarrior development studio for micro-controllers software. This standard integrated design environment enables customers to quickly implement custom algorithms and features to exactly match their application needs. Using the master I2C port, the MMA955xL device can manage secondary sensors, such as pressure sensors, magnetometers, or gyroscopes. This allows sensor initialization, calibration, data compensation, and computation functions to be off-loaded from the system application processor. The MMA955xL device also acts as an intelligent sensing hub and a highly configurable decision engine. Total system power consumption is significantly reduced because the application processor stays powered down until absolutely needed.
This device is optimized for use in portable and mobile consumer products that can make system-level decisions required for practical applications such as gesture recognition, pedometer functionality, tilt compensation and calibration, and activity monitoring. This may be applicable to tablets, digital cameras, smartbooks, laptops, gaming and security system as well as used in medical applications.
Intelligent Motion-Sensing Platform – [Link]
Praveen from CircuitsToday has written up an article on interfacing PIR sensor to 8051 microcontroller:
PIR sensors are widely used in motion detecting devices. This article is about interfacing a PIR sensor to 8051 microcontroller. A practical intruder alarm system using PIR sensor and 8051 microcontroller is also included at the end of this article. Before going in to the core of the article, let’s have a look at the PIR sensor and its working.
Interfacing PIR sensor to 8051 microcontroller – [Link]