Impress your friend with the ultimate geek’s Birthday Cake! A hand-made open source electronic cake with candles you can blow out!
- Features 9 LED candles that you can blow on, to make them flicker and go out, like you do with a real birthday cake! Each candle blinks with random period and phase that depends on the intensity of the air flow
- Piezo sensor and a special air trap to detect air flow with astounding sensitivity using resonance effect
- Atmel ATTiny44 microcontroller on board with 4 kilobytes of flash memory and 256 bytes RAM
- Open source hardware and firmware. Can be re-programmed with an ICSP programmer or Arduino board via Arduino IDE
- Size 42 x 42 x 18 mm, weight 26g
- Powered by a single AAAA/LR61 battery (included)
- 3.3V step-up converter on board
- Ultra low shutdown current (less than 1 uA in deep shutdown)
- Hand-soldered using lead-free solder
BitCake – Electronic Birthday Cake - [Link]
SosElectronics offers you simply applicable solution of a power LED on a thermal clad in a special offer!
- power white SMD LED Luxeon Rebel
- luminous flux min. 100 lm / 350 mA
- specified to continuous 700 mA / 3,2 V
- made on a ceramic base with electrically insulated thermal pad
- guaranteed lumen maintanance 70% of original value at 50 000 hrs / 700mA / Tj 135°C
- low moisture sensitivity – JEDEC Level 1
- dimensions: 4,61 x 3,17 x 2,10 mm
- thermal clad for Lumileds Luxeon Rebel
- optimal heat transfer from LED to heatsink
- longer LED lifetime and luminosity thanks to a lower operating temperature
- star board
- easy application
Readily usable LED for exceptional price - [Link]
by Donald Schelle @ ti.com:
Achieving optimal performance of an LED luminaire or LED backlight design requires numerous trade-offs. Understanding an LED’s power transfer characteristics empowers intelligent choices regarding cost, power consumption, and weight. While most LED datasheets publish pertinent data that can be used to make these decisions, data may not be formatted in a way that is readily applicable to the chosen application. Optimal performance requires finding pertinent information from manufacturer’s LED datasheets and utilizing methods to capture, reformat and analyze the data.
Optimal operating point of an LED - [Link]
by Henry Tonoyan @ htonoyan.blogspot.gr:
Last week I had the idea to create a last-minute valentine’s day gift for my girlfriend. I had a bunch of WS2812 LEDs from my previous endeavors and decided to make a big LED heart. These are a great choice because of the very minimal amount of components necessary: no I/O expanders, driving transistors or ICs necessary. Plus you just need one I/O line from your microcontroller to drive them.
Since they run off 5V, I planned to create a board that is powered from a wall-wart power supply. That way the board doesn’t even need a voltage regulator on it. I chose to use an ATMega48 because I have several from previous projects.
A Valentine’s Day Surprise - [Link]
Markus Gritsch shared his WiFi LED light project in the dangerousprototypes forum:
I built a prototype for a WiFi controllable LED light, using the popular ESP8266 module running the NodeMCU firmware . To allow controlling the WS2812B LEDs from Lua, I extended the firmware with a bit of C code
WiFi LED Light (ESP8266 + WS2812B + Lua) - [Link]
by Rusivan @ instructables.com:
In this article I will try to tell you about the gift I made for my girlfriend!
The basis of the scheme is a microcontroller Atmega8, 1K resistor, selected in such a way as not to overload the microcontroller ports. SMD resistors and diodes, size 1206.
On the reverse side of the board, there are two batteries CR2032, two capacitors, voltage regulator LM7805, and the power button with latching.
DIY SMD LED heart - [Link]
by Phil Townshend @ edutek.ltd.uk :
A nifty 32×7 dot matrix display module, programmable via an RS232 serial port. There are preset inputs to display preset messages or simply control directly from a PC or laptop.
The principle of the display is based on our persistance of vision, the same thing that enables us to watch movies without seeing the flickering changes of frame. This display has 32 LEDs horizontally by 7 vertically. At any one time there is only ever one column of LEDs lit. The on’s and off’s are presented to the anode connections while the columns are enabled one by one. In this way a dot display of characters can be generated and when the speed is increased sufficiently, we stop seeing the flickering and see it as a steady display of dots.
LED Dot Matrix Display - [Link]
Joe @ hobbyelectronics.net:
Here you will find complete construction details including circuit diagrams, PCB layouts and PIC firmware (and the source code). The code was written in Proton PIC BASIC but the good news is that there is now a free version of this compiler available for download; AMICUS18.
PIC Digital Thermometer & Clock - [Link]
Sometimes you learn about an interesting IC and you build an entire circuit around it for no other good reason… This project is one of those!
The TPS2378 is an IEEE802.3at (Power over Ethernet) Powered Device controller, featuring internal pass MOSFET for loads up to 25.5W, Type 1 (a.k.a. 802.3af) compatibility and auxiliary power source support.
The IC is normally used together with a DC-DC step down regulator to power a network device (the PD) from a PoE compliant switch or injector (the PSE). A proper 802.3at device requires an isolated power supply with some safety characteristics that makes it not trivial to implement, and there are many DC-DC ICs with integrated PoE controller to make it easier, but as I wasn’t really interested in that part I just went for an easier project with just the PoE controller and some ballast… And what better ballast than some high power white LEDs!
Power over Ethernet Flashlight - [Link]
by Steven Keeping @ digikey.com:
The majority of contemporary LEDs are constructed from a combination of Indium gallium nitride (InGaN) and sapphire substrate. The architecture works well and has allowed LED manufacturers to offer products exhibiting efficacies in excess of 150 lm/W. However, the architecture does have some drawbacks which have encouraged chipmakers to seek other options.
One commercially successful alternative is silicon carbide (SiC), and LEDs based on the substrate have been on the market for two years. Now a new generation of the technology has been released that promises to double the luminosity of the current brightest single LEDs and cut lighting fixture costs by 40 percent.
Silicon Carbide Substrate Boosts LED Luminosity - [Link]