by Kathy Yang @ elecfreaks.com:
ElecFreaks will launch a multi-axis unmanned helicopter series: ELF. As the name suggests, this series will be surprisingly tiny. Aimed to design a very compact, portable, able to fly in any place multi-axis helicopter, we will use smart phones app (must support Bluetooth 4.0) instead of remote control. Smaller also means more security and therefore would be more suitable for various occasions and people. If you are a child, this helicopter will be like any other toy of yours. Like always, we will open source all the information. If you are an advanced gamer, this helicopter will be perfect for research and development. If you are just a junior gamer who don’t care details that much, it’s totally ok, ELF got novice mode to allow press-one-key takeoff.
Drone ELF First Successful Trial Flight - [Link]
by Boris Landoni @ open-electronics.org:
Since when white light emitting high brightness LED are available, the handover from traditional lighting bulbs to the solid-state lighting has become irreversible: LEDs have an efficiency (expressed in lumens/watt) higher than that of almost all the traditional lamps (except, at the moment, the large sodium vapor lamps used for street lighting, unusable in closed environments for the high power required and the chromatic aberration they produce) at a cost that is today less prohibitive than it was a few year ago. They are indeed very sturdy and have a very acceptable ratio of luminous flux and size.
The perfect Remote, Programmable, Controller for interactive LED strips - [Link]
An all-in-one, water and sand resistant, solar charger, audio speaker system, and sunburn timer calculator by starwisher. Check out the project’s instructables page here:
This Instructable harnesses the power of Arduino, a UV sensor, and simple mathematics to make one nifty gadget sure to boost your outdoor summer fun – and minimize your indoor summer recovery!
Beach Buddy, a 3-in-1 solar phone charger, boombox, and sunburn timer calculator - [Link]
by Edwin Chen @ open-electronics.org:
The model of this shield named Yun Shield, the feature of this shield is as its name. User can add this shield into Arduino (Leonardo, UNO, MEGA2560 etc) and “turn” the Arduino into device which has similiar features as Arduino Yun: support remote upgrade and use the Bridge library.
With this shield, user can easy to set up communcation between Arduino and Internet (via ethernet , wifi or 3g etc) and add support for USB flash, video. The detail user guide/ manual can be found in the dragino website and most Arduino Yun Sketch / examples can reuse with this Shield. This shield is under production and will be ready within one months time.
Add Linux, WiFi, Ethernet and USB to Arduino - [Link]
Kyle wrote an article detailing his DIY automatic water timer:
Now that I have power and output figured out, I need to work on the control aspect. 555 timers are great for simple applications requiring up to a few minutes of delay. At 10 minutes, the RC values needed would boarder the danger zone of the timer not functioning correctly due to the leakage current of the capacitor and the small charge current of the resistor. I could have cascaded two or more timers together but that would be sloppy so I fell back on my trusty friend – the ATtiny micro controller. This would allow me to make changes as I want without redesigning the board.
DIY automatic water timer - [Link]
A simple temperature control system for 3D print or other constant temperature control purpose by Xiang:
I plan to build a home-made 3D printer controlled by my Raspberry Pi, which, unfortunately, does not have any analog data acquisition pin. Therefore I decide to build a stand-alone temperature control system.
The idea is very simple. I use a power resistor as the heater and a thermistor as the temperature sensor. The system contains an LM324 quad op-amps chip. One op-amp is used as a comparator to compare the thermistor resistance with a nominal resistance and output LOW or HIGH as the comparison result. The other three op-amps inside the LM324 are used to perform some linear transformation and output a voltage that is proportional to the thermistor temperature. This voltage is applied to a 0-30V voltmeter so one can read the temperature. A N-Channel MOSFET transistor is used to control on/off of the heater.
Simple temperature control system - [Link]
Jianan Li made this LiPo Booster project, that is available at Github:
LiPo Booster is a breadboard-friendly boost converter board based on the TPS61230 IC from Texus Instrument. It has an output voltage of 5V, and is designed to be used with a single cell LiPo battery.
LiPo Booster, a breadboard-friendly boost converter board based on TPS61230 - [Link]
by BABU TA @ edn.com:
This flasher/beacon circuit can be employed as a distress signal on highways, a direction pointer for parking lots, hospitals, and hotels, etc. The circuit uses a power LED, and provides more light than a typical incandescent lamp flasher. Use of a 6V or 12V SLA lantern battery makes the circuit portable.
HB-LED flashing beacon repurposes switching regulator - [Link]
by raptor_demon @ instructables.com:
What is this? it is a arduino compatible (ATMEL 328p) based home bathtub controller.
this controller sets the depth, adds bubbles and monitors the temperature of a bathtub based on a user profile. v2.5 has support for Internet of things but it is not fully implemented.
But why? Well why not? ever wanted to have a bath ready at a touch of a button or from your smartphone (coming soon)?
Arduino Compatible Bathtub controller - [Link]
Kerry Wong writes:
As I mentioned in my previous posting, there was an issue with my Wavetek 907 microwave frequency generator. While everything was fine during my initial testing, the frequency display is now stuck with an out-of-range display and the adjustable frequency range is limited to between around 6.9 Ghz to 7.9 Ghz (instead of all the way up to 11 Ghz). My initial suspicion was that the PTC heater inside the YIG-Gunn oscillator was malfunctioning. But as it turned out, it was something else.
Since initially my gut feeling told me that the YIG oscillator might be at fault, I thought I would at least try taking it apart to see if it was something trivial to fix. And even if it is beyond economical repair, it would at least be a pretty interesting teardown of the YIG oscillator itself.
Wavetek 907 repair, YIG oscillator teardown - [Link]