- No power supply needed: The circuit “steals” in the operating current (only 10µA at 5V and 2.5µA at 3.3V) from the signal lines of the camera
- Interval adjustable from 0.4 seconds to about 18 minutes
- No controls, setting of the intervall via “teach-in” from the camera
- Ultra-portable: the circuitry fits into the housing of a 2.5mm stereo plug
- Component cost: 87 ct (July 2010)
Intervall Timer for Nikon and Canon DSLR - [Link]
In Los Angeles, we have the “Time-of-Use Program” option from the power company. From their FAQ:
The prices are based on the time of day when the electricity is actually used, unlike the standard rate when the price for electricity is always the same.
A higher price is charged during “high peak” hours, which are between 1:00 p.m. and 5:00 p.m., Monday through Friday. The price for electricity during these hours is about twice the cost of the standard rate price.
Surrounding these “high peak” hours, are the “low peak” hours. “Low peak” hours are from 10:00 a.m. to 1:00 p.m. and again from 5:00 p.m. to 8:00 p.m., Monday through Friday. The price for electricity during these hours is slightly higher than the price charged on the standard rate.
During all of the remaining hours, Monday through Friday, and all weekend long, the price for the electricity you use is about one-half of the price for electricity on the standard rate. These hours are called “base” hours.
I was lucky in that my house came with a mechanical timer (as part of some Frankenstein solar system). It was easy to set it to turn off the hot water heater from 1 to 5pm. Don’t forget about daylight saving time, oh how I hate daylight saving time.
This worked fine except for the most weekends we would forget to reach into the box and turn on the hot water before during laundry or grabbing that all important weekend noon shower. Even the ridiculous note didn’t help.
Smarter Water Heater Timer – [Link]
dangerousprototypes.com writes: [via]
What’s in a name? David L. Jones of EEVBlog thinks he’s found an Easter egg in the performance characteristics of the 555 timer chip which reveals the basis of the “555″ in its name. Build his circuit (schematic at video 13:25), fire up the scope and see if you agree!
555 timer Easter egg? - [Link]
The USGS maintains a server online that consolidates all the seismic data received from sensors all around the world. Terremoto uses an LPC Expresso board and an XPORT AR ethernet module to query the USGS server for a list of earthquake activity. When a new earthquake is received by Terremoto, tones are generated that correlate with the magnitude of the earthquake.
Terremoto – Earthquake Sounder based on the 555 Timer – [Link]
One of the applications of 555 timers is a class D amplifier. In its most simplistic form it can be built with a single 555 and the 200mA current capability is enough to drive a small speaker, making it a good replacement for a low power amplifier. But I wanted more; I wanted to use it to build an amplifier that had enough power to allow listening to music in a small room. Adding a high power stage to a classical 555 class D amplifier was too easy, so I decided to build my own high power 555.
555 class D amplifier - [Link]
In this Countdown Timer project, a 555 IC, a counter IC and a transistor switch to activate a relay either ON/OFF(mode selected by a jumper) as soon as the counting period is over. The circuit consists of an oscillator, a ripple counter and two switching transistors.
Simple Count Down timer Project – [Link]
A matrix keypad uses rows and column arrangement of keys to reduce the required number of I/O pins for interfacing with a microcontroller. This article shows how you can use a 555 Timer IC to interface a keypad with just 2 connections. The 555 timer is configured in astable multivibrator where the output frequency changes with each key press. Based on how many times the Timer module overflows, the information about the pressed key is determined.
2-Wire Keypad Interface with a 555 Timer – [Link]
The story of the triple nickel. Jeri writes – [via]
In this video I go over some of the history of the www.555contest.com and how it grew from a few random events. I also demonstrate an AM transmitter that broadcasts tones depending on the temperature of a thermistor.
The Story of the 555 contest and Temperature to Tone Transmitter – [Link]
All AVR microcontrollers have internal watchdog timer that can be successfully used in your projects. Atmega328 and other modern AVR microcontrollers have so called Enhanced Watchdog Timer (WDT). It has few very useful features including: separate 128kHz clock source, ability to reset microcontroller and generate interrupt.
Using watchdog timer in your projects - [Link]