How do I make a scrolling sentence with this?

roughwire

I've got no money and no time but I've got a dual 7 seg. LED· (pic attatched) that I need to programm to spell out something through my board of edjucation. What can I do with this?

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MIKE

Chris Savage

roughwire,

I would recommend focusing on one project at a time…In this thread you mention not having any time and in another thread you say the same thing asking for help on an unrelated subject. You may want to take on one thing at a time and focus on the task until completion. I hope this helps. Take care.

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Chris Savage
Parallax Tech Support

roughwire

I'm throwing out a bunch of differnt things because I've got to have something done in like 3 days, so what ever I can get done first is what I can show my professor.

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MIKE

allanlane5

Well, if you say you've got SOME money and three days, we might be able to help. That's a dual, 7-segment LED display. Common Anode or Common Cathode I can't tell.

It's kind of hard to 'spell' with those. They do numbers and hexadecimal great, though. I think a 74HC595 and some current limiting resistors and a transistor or two would enable you to interface with it -- but putting it together and debugging the hardware could easily take 3 days, never mind the software.

And it's Wednesday, January 10th. Waited a little late, didn't you?

We'd like to help, we really would. I'm sure lots of us have been there, done that. Do you perhaps have a list of projects you could ask us about, and we'd steer you to the most easily implementable?

roughwire

Sure no prob. I need to do one of the following:
Balence my boe bot on two wheel without a PING, but I do have an NXT ultrasonic but it has a phoneline jack?
Make it speak some recordings of my voice and/or make at least scrolling letters,

My bigest problem is I don't have any time to get the right things so I'll have to impravise....

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MIKE

allanlane5

Of the three you called out, the 'scrolling letters' is probably the most straightforward. Still, three days is really optimistic for that.

You need to start with a schematic or pinout of the 7-segment LED module.

Forrest

I don't know how you can display k, m, q, v, w, x or z on a 7 segment display.

PJAllen

Forrest said...
I don't know how you can display k, m, q, v, w, x or z on a 7 segment display

As long as you don't need those letters, then it's a cinch, anyway.· Mind you, the·Romans didn't have J, U, W, Y, Z and look how far they got.
I'd like to see it do "board of edjucation", especially for the sake of the·professor.·
Making out a scroll on a two-character display will require concentration.

MikeK

If you limit yourself to a single case, then you can do those letters (I found a "standard" (I apply the term loosely) someplace, but I don't remember where).

For example, you can make an "n" from the two lower vertical bars, and the center horizontal bar. An "m" can then be all four vertical bars, and the top horizontal bar. "H" and "k" are what would normally look like an upper case (H) an lower case (h) H. I don't remember which is "h" and which is "k", though. "q", "9", "6", and "g" are combinations of the upper square and lower-right vertical bar, with/without the bottom horizontal bar, and the lower square and the upper-left vertical bar with/without the upper horizontal bar. I don't remember X, but who needs it other than radiologists . "z", also not especially common, can be what looks like a lower case "c", if you want. "U" is what looks like an upper-case "U". "w" is what looks like a lower-case "u" (or you can use that for "v").

I did the menus for setting a clock using this method using one of Bean's HC4LED modules. It worked out okay, but of course I'm the only one who ever needs to use it.

Mike

Phil Pilgrim (PhiPi)

Here are KMQVWXZ. "They don't look like those letters", you say, "and the X looks like an H." True, but in context (within words), they work quite well. You have to provide the context, though, and two characters won't be enough -- especially for a scrolling display. Four would be an absolute minimum; eight would be more reasonable.

-Phil

AIman

Whats a microcontroller, chapter 7 I think, goes into using the display type you need for creating single letters. It would be easiest and fastest to download the book from the Parallax website and read the portion for the LED display. It even gives diagrams on how to hook up the circuit.

Good Luck