Pitt Meadows build a weather station based on ATMEL ATMega168 microcontroller. He writes:
The Small Weather Station is a battery-operated, wireless, weather station. I have been working on the project for almost a year now, and now I have an unshielded prototype that is partially functional. I say partially functional, because it does not have any wind/rain sensors installed, only the connections for them. So far it can log several things: temperature, humidity, atmospheric pressure, and battery voltage. However, the connectors for the rest of the sensors are functional; the only thing they require are several magnetic reed switches.
ATMEGA168 Weather Station – [Link]
Bob build a tiny and easy to build function generator. He writes:
Function generator is a rely useful tool in the lab, a simple version can be build at home, there’s a lot of examples on the Internet, some are much more complex and powerful, but this one is intended to be really simple and cheap. It can be also built-in in some bigger projects that also requires a generator.
The generator can output (only) square signal with adjusted frequency and pulse width. The amplitude may be also modified by soldering different values on the voltage divider on the output, it’s a bit laborious, but if it will be used in digital or microprocessor projects, then there isn’t really need for amplitude adjustment.
Tiny and cheap lab generator – [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 techrm @ instructables.com:
Today we are going to show you our first experiment on the Internet of Things. For this purpose, we decided to use an Arduino MEGA instead of an Arduino UNO. That’s because Arduino MEGA has more than one serial port and this fact allows us to use the ESP8266 and the serial monitor at the same time. As written in the title, we’ll see how to monitor some of the most important plant growth factors*. These parameters are: Ambient temperature and humidity Soil moisture and temperature Illuminance
WIFI plant monitoring system based on Arduino MEGA and ESP8266 – [Link]
Bob @ robertgawron.blogspot.com
The Geiger–Müller counter is a relatively simple tool to measure ionizing radiation. This construction of the Geiger–Müller consist of three (instead of one as usually) soviet STS-5 lamp to increase sensitivity. It’s important for measurements of natural sources of (low) radiation like soil, rocks (an article about my trip with Geiger–Müller counter on Śnieżka mountain). I have also in plans building my home radiometric station (it would be part of part of a weather station) connected to the web, so I get the data wherever I am.
Geiger–Müller counter with three STS-5 lamps – [Link]
This video (by request) gives an overview of how to the FFT Math function on the Tektronix TDS2000 series oscilloscope. (same applies to the TDS1000). A brief review of FFT fundamentals is given, followed by a demonstration of using the FFT function and controls, ending with a description of the mathematical relationships between the scope settings and the FFT results. More modern scopes will have different (easier to use) controls for the FFT than this 12+ yr old scope, but it is instructive to understand the operation of this feature.
Basics of using FFT on a Tektronix TDS2000 oscilloscope – [Link]
12V Lead Acid Battery Monitor is a simple project which tells you the voltage of your Lead acid battery visually with the help of 10 LED’s. This project is based on the popular LM3914 IC from Texas Instruments.
The LM3914 senses the voltage level at the input pin and drives the 10 light emitting diodes based on the voltage detected on input connector. Circuit works on same battery, doesnt not require separate supply input. Jumper is used to select the DOT mode or bar graph mode.
12V Lead Acid Battery Voltage Monitor – [Link]
by TheSpodShed @ instructables.com:
This is a magic box which will let you monitor the power consumption of your house from anywhere on the Internet! It measures both true power (Watts) and apparent (VA) power, it keeps a running total of electricity units used, and measures mains frequency as a bonus.
The project uses a Particle Core(*) module – a little board with an ARM microprocessor and a Wi-Fi interface – to do all the hard work. To build it, you’ll need to be able to solder and follow a simple circuit diagram. At UK prices, total parts cost should be no more than £50.
Internet connected home energy monitor – [Link]
by SwitchDocLabs @ instructables.com:
WeatherPi is a solar powered Raspberry Pi WiFi connected weather station designed for Makers by SwitchDoc Labs. This is a great system to build and tinker with. All of it is modifiable and all source code is included.
WeatherPi – Solar Powered Raspberry Pi weather station – [Link]
Dilshan Jayakody has published a new project, a DC millivolt source:
DC millivolt sources are often used for thermocouple simulations, DMM, ADC and analog circuit calibrations and fault findings, etc. Most of the DC millivolt circuits are based on expensive (and sometimes hard to find) operation amplifier like OP7, LT1077, etc. In this article we introduce low cost DC millivolt source based on commonly available LM308 precision operational amplifier, ICL8069 low voltage reference and 78L05 voltage regulator ICs. This millivolt source is design to obtain 200mV – 700mV DC output with 100Ω impedance. At the time of writing we spend Rs.800.00 (LKR) to complete this project.
Low cost DC millivolt source – [Link]