Hi. I am beginning in electronics, and am taking classes at school. There is one thing though, that I would like to know how to do... just basically out of curiosity. I have 10 LEDs, and I want them to start on the outside, and go to the middle... this is sort of a diagram... (O being the lit LED. There aren't 5 lines of LEDs, that is all the same line and how they light up.) OXXXXXXXXO XOXXXXXXOX XXOXXXXOXX XXXOXXOXXX XXXXOOXXXX I have made a video, and here is the link, if it doesn't work I will upload someplace else. Code: jpme.mooo.com/www/site/led.wmv If anyone knows how I would go about doing this any info would be great!
Welcome to the forums. You may wish to look at counters and a decoder (like a 3x8 DeMux) to implement what you want. Basically you will need a counter, modulo-5, feeding a 3x8 Demux. This should get you what you need since to mirror the sequence from the other direction, just tie your original five to the other five.
Yea, I thought about tying them like you said... and I will look into that.. Will I need to program the counter or anything fancy like that?
Also, are there any HOW TO's for these counters? I am new, (as I said) and I don't completely understand all of the schematics, and how the chips work... Lol, the 555 still gives me trouble...
It is up to you if you wish to go the software or hardware route to implement the counter -- just depends on what you prefer as well as available resources. There are some ready made counters available in several of the logic families that are of some modulo type, usually 10 or 16, and can be easily converted to mod-5 if you do not wish to go through the trouble of dealing with flipflops. Conversion to mod-5 from a counter can be as simple as adding one gate and connecting it to reset. The reason I suggest a 3x8 Demux for a decoder is because you can use it as a one-hot decoder and it is straight-forward to wire up. As for the programming route, besides using something like a FPGA, a PIC is usually a good option. There are a few gurus on this forum who are well-versed in Microchip's PIC and would be glad to lend a hand. Edit: As for how the chips work and other things as well, this website is pretty good at explaining various things. For specific questions, we will gladly answer them.
Do you have an AIM/Yahoo/or MSN? I have these, and I can add you... I am still a little 'stupid' with it.. I have looked at the pages and tried to read some but became confused =/. I don't want to be annoying or anything, and if I am... say something heh.
I am one of the weird ones that have not participated in instant messaging unfortunately. You are not annoying; learning something new, especially electronics, is a challenge. The fact that you are actually interested in learning is a good attribute. What have you covered so far in the electronics portion of your class by the way.
http://www.bit-tech.net/modding/2002/06/22/knight_rider/1.html Good old bit-tech has done it before! Interestingly, this is the article which led me to discover the site, as I was looking for a knight-rider LED circuit. I'll be glad to walk you through the 555 timer (need to brush op on that though) and counters etc. You have a PM regarding IM adresses
Yes, I saw the knight rider light, and found that cool, but it isn't really what I was looking for, but it is close... Do you think, if I had something like that, that I could make it a mirror? so it looks like it goes for the outside in? In electronics we have learned most of the laws, working with series/parallel, how to find most measures... we started working with oscillators and next year we will start with all of the AC junk. there is more that I have learned, I just dont want to type it all =P
That would work as well. To make it go from outside in, just physically exchange what you normally wire for LED number 1 for the last LED (maintaining correct bias of course) and so on for the rest.
You can do this with the standard 555/4017 circuit and a few steering diodes to give the back & forth movement; a slight modification of this circuit using a pair of 4017's from the same 555 clock to give the "other half" or using each steered pair of outputs to light two LEDs on opposite sides. The latter way may need current-boost transistors on the outputs, so the pair of 4017's is cheaper and simpler.
Ok, I have the parts for the circuit you suggested, Cpemma. But I have some questions. On that circuit, there are some things on the 4017 that I don't know which pin it is... Like the EN, R, one close to there looks like an o, and the ÷10.... on this site, http://www.doctronics.co.uk/images/4017_01.gif, it shows the EN, and R... but not the other two, if you could help out that would be great
The first (like an 'o' or more like o>) is the symbol for a clock input (pin 14), connecting to the 555. '÷10' is a 'carry' output (pin 12) which could be used to clock a second 4017 counter to count up 1 for every 10 counts on the first, but it's not used and not connected in this circuit.
Ok, I am working on it now, and trying to get it to work in a bread board, but I have to stop for awhile because I am going on vacation... I will be back in about 10 days, so see you all soon.
Ok, I am back from vacation, and I will try to work on this later... I have some school stuff to work on ><. So I might not be able to work for awhile...
I swear, whoever designed the pinout for the 4017 just wanted to piss off PCB designers... I mean, how hard can it possibly be to have the outputs in a sensible order?
