This project is a cheap rain sensor able to detect the occurrence of rain. The sensor automatically triggers a buzzer when a rain drop is detected and thus giving early indication of rain. The circuit is powered from AA batteries and it draws no current when in standby and consumes little power when the buzzer is on. It is easy to build and install.
Rain Detector Sensor - [Link]
Jeri shows how to make a flexible display with aluminum foil, EL phosphors and a simple electrolytic etching bath.
Flexible Aluminum Electroluminescent Display – [Link]
Jim Schneider has build a temperature and light datalogger to tell if a refrigerator door was open or closed. The datalogger has the ability to change the log interval on the fly (1 – 1023 seconds), to log 2 sensors at once, to choose which sensor to log, to retain data when power is lost etc. Check construction details on the link below. [via]
Temperature and Light Datalogger - [Link]
Andrew Schamp has build a temperature datalogger to measure the temperature in his garden. He used a TC74 temperature sensor, 24AA1025 1024kbit EEPROM and a DS3231M+ real-time clock to record the time and temperature hourly onto the EEPROM. He also implemented a serial interface for reading the data at the end of the sampling period. The device is based on Arduino-compatible Boarduino. Every hour, the device takes a sample, and then goes to an extended sleep state, to be awoken an hour later by the interrupt from the RTC. [via]
Embedded temperature datalogger – [Link]
Greg Charvot has build this Homebrew Radio Transceiver for the 20 M SSB ham radio band from scratch. It is build using solid state components in low noise design philosophy. It uses a bi-directional signal chain rather than a separate transmitter and receiver. Check schematic and construction photos on the link below. [via]
Homebrew 20 M SSB Radio Transceiver – [Link]
This project is an automated Android controlled cat feeder based Arduino board. The attached HTC Magic is running SL4A and provides scheduled and on demand feeding as well as an MJPEG webcam feed. The Arduino is hooked up to a SparkFun BlueSMiRF and a simple relay circuit to control the motor. The brackets and food chute were designed in SketchUp and printed on MakerBot. Check it out on the links below. [via]
Android controlled cat feeder – [Link]
This is a solar powered robotic mobile that combines solar energy and Bluetooth module. It’s another kind of art by Mark Malmberg.
Solar Powered Robotic Mobiles - [Link]
This project is a WIFI Access point repeater that is powered from a wind turbine. No schematics are provided.
Wind-powered WIFI AP repeater – [Link]
This project is a gear position indicator able to display the gear number for Suzuki V-Strom (DL650 and DL100) motorcycles. These motorcycles have the gear position sensor installed so it is possible to show gear number without any delay and with 100% accuracy. The sensor is read by an ATmega88 microcontroller and the gear is displayed on a 8×8 LED matrix. There is also a temperature and a light sensor installed so it can display the temperature reading and it is able to dim the LED light according to ambient light. Check details on the link below. [via]
Gear indicator for motorcycle Suzuki V-Strom - [Link]