Charalampos Andrianakis writes:
Two years ago i modified a scanner replacing its mechanism and all the internal electronics with UV lamps converting it to an UV exposure box for PCB prototyping. By the need of making my life easier and not waiting for the pcb to be exposured i designed an AVR timer to automatic switch off the lamps after 1 minute of exposure which was much enough for the PCBs. Here is the circuit
This was one of my first completed projects from design to production. As you can see the scheme isn’t that good and there have been by passed some capacitors at the power supply. But the circuit works with no problem.
AVR Switch Timer - [Link]
Goal is to replace this Ikea super cheap timer that works … well, as good as something manual that you paied less than 200 JPY (less than 2 euro). Not precise, sometimes doesn’t ring, or ring just the blink of an eye, so easy to miss…
The new timer will:
- Have a graphical LCD (bought one one year ago, never used it, needed a pretext, so…)
- Work on battery (1x 9v battery)
- Play music when it’s time
- Use a speaker and amp
- Possibly use a YMZ294 ?
- In fact something else but much better…
- Have an on/off system with a push-button, not a open/close switch In fact a tilt switch
- No arduino, but a simple atmega 328 (more than sufficient)
- Keep me busy a few days while allowing me to use some parts I bought long time ago and create a un-reasonable and out of price kitchen timer
Arduino KitchenTimer - [Link]
Last week I was browsing my old backup hard drive and I found a source code for a very simple PIC based digital timer that I made a couple of years ago. The actual hardware of the project isn’t with me anymore. I might have lost it when I moved from my old apartment into my new home. However, I thought this might be a good practice project for beginners and so I am sharing it here. I am not going to build it from scratch again; I will rather demonstrate it using my DIY PIC16F628A breadboard module and I/O board. The complete circuit diagram along with the firmware developed using mikroC Pro for PIC compiler is provided in the article.
00 to 99 minute timer using PIC16F628A microcontroller - [Link]
This instructable will guide you through creating your own Arduino based Kitchen Timer. This is a quite simple project, requiring little or no programming or electronics knowledge, just the willingness to learn and fiddle – an ability most useful for modern man.
This kitchen timer is simple enough, press and hold a button and it will count up it multiples of five minutes, until you release the button. Upon doing so the timer will flash, and begin counting down. This timer includes an alarm and a display, with a piercing piezo buzzer to get your attention.
The arduino, laptop, protoshield, and USB Cable excluded; I took every electrical component from an old or broken device. Try to recycle things, its easy to get hold of broken electronics for free so make the most of it! See any jumpers on this design? No, paper clips are much better – cheap as chips and more sturdy too!
Arduino Kitchen Timer - [Link]
- 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]