This project is a solar powered Arduino based weather station and digital thermostat. Device is able to display temperature, humidity, barometric pressure and time/date. The sensor used is a SHT21 Temperature Humidity sensor. It is also equipped with a RGB led to display how comfortable the conditions are.
Solar powered Arduino based weather station / digital thermostat - [Link]
This project is a temperature – related humidity meter using a Nokia 3310 LCD, a HSM-20G sensor and an Arduino board. Check construction details on the link below.
Nokia 3310 LCD and HSM-20G temperature – humidity sensor - [Link]
This instructable explains how to interface a 4×4 keypad over an I2C bus. I2C is a 2 wire bidirectional bus to which addressable devices can be connected. This will help to interface a keypad using only a few IO pins. It uses I2C remote I/O expander chips, a 4×4 keypad and a 7 segment display as output device.
How to interface I2C keypad - [Link]
This project is a mini FM bug build using spare parts of a mobile phone. The range of this FM bug is around 1km with full CR2032 battery and good conditions. You can download schematics on the link below.
FM bug 420-480 MHz – [Link]
This instructable shows how to build your own rainbow LED strip based on PICAXE-08M microcontroller. The light strip consists of a flexible copper tape with very bright surface mount RGB LED’s and each pair of LED’s is controlled by an HL 1606. The instructable user “johncohn” has reverse engineered HL 1606 to find out the signaling required to drive the strips. The signal required was a SPI – Serial Peripheral Interface. Check the details on the link below. [via]
Rainbow LED Headband - [Link]
This software radio made by PA3FWM is capable of capturing nine amateur radio bands (VLF, LF, MF, 160m, 80m, 40m, 30m, 20m, 15m) simultaneously. The radio receiver is controlled by a nice web interface that let’s you control which band you would like to listen. Check it out on the link below. [via]
9 band amateur software radio – [Link]
This project describes how to make a digital voltmeter using a PIC microcontroller. A HD44780 based character LCD is used to display the measured voltage. The PIC microconotroller used in this project is PIC16F688 that has 12 I/O pins out of which 8 can serve as analog input channels for the in-built 10-bit ADC. The voltage to be measured is fed to one of the 8 analog channels. The reference voltage for AD conversion is chosen to be the supply voltage Vdd (+5 V). A resistor divider network is used at the input end to map the range of input voltage to the ADC input voltage range (0-5 V). The technique is demonstrated for input voltage ranging from 0-20 V, but it can be extended further with proper selection of resistors and doing the math described below.
PIC16F688 Digital Voltmeter - [Link]
lucidscience.com has build a 2 transistor Spy Transmitter that will send the sounds picked up in a room to any FM radio tuned to the same frequency as the transmitter. Check construction details on the link below. [via]
This project is focused towards those who have not yet attempted to build any kind of RF project, and it is laid out in such a way as to make it easy to explore the basic principles of RF circuitry and ensure a successful final product.
Tiny 2 transistor Spy FM Transmitter - [Link]
This project shows how to build a Panaplex display using some electrodes and a jam jar as the vacuum chamber. Panaplex is a gas-discharge plasma display related to the Nixie tube. The builder, Lindsay Wilson, explains how it works:
The entire thing is based on using a jam jar as a vacuum chamber. Each of the cathode electrodes is made from a 2cm length of copper wire. A stainless steel M3 screw is soldered to the middle of the wire. This allows it to be screwed to the support plate, which is made from a piece of ceramic tile. It was very easy to drill the 3mm holes with a diamond drill – the tile is made from sintered ceramic powder and is quite soft. A solder tag is mounted on the back of each cathode screw which allows electrical connection to be made to the respective cathode.
Homemade Panaplex display - [Link]
The µVGA-II(SGC) is an embedded module able to produce VGA graphics using simple serial commands. It can easily connected to any host microcontroller that can communicate via a serial port and procude VGA signal. The module is powered by the PICASO-SGC graphics controller and it can provide QVGA/VGA/WVGA graphics, text, image, animation and more features. Check details on this module on the link below.
µVGA-II(SGC): Serial to VGA graphics module - [Link]