POV help

[Omar.M]

Hello everyone,
I have recently gotten some led blinking to work, and I am enjoying the time I am spending learning how to program, and use the PIC 16F628A microchips.

So now, I have seen these things everywhere, POV (Persistance of Vision) and I want to make one myself... but don't know how. Didn't you see that coming Razz?

I have seen some fairly simple ones, but I want to use My chips for them not the other ones like the TINY chips etc.

So my question to you:

Anyone have any tutorials and such I can follow (simple simple ones. I mean I just want to make a few words like "HELLO!" Or something when I wave this thing around) that use 16F628A or use code that is compatible with this device for POV?

I have seen one of the easier ones here: https://www.ladyada.net/make/minipov/index.html but I am not sure if this is possible with my chips...

-Omar

P.S-- I am quite new at this place, but I have been looking around the site for a while now. Nice to meet you all!

 

[House0Fwax]

Start off by getting 7 leds to flash. Then write out your message on a 5 x 7 grid. I.e 00000000 = all off and 011111111 = all on. Then in sequence, 1 x 011111111 + 3 x 00000100 + another 011111111 would show up as an 'H' on the display when waved. You'd have to sort out a delay between each set of instructions depending on your particular set up.
I made one a while ago using 3mm leds and a 16f627.

 

[Omar.M]

Oh

Well thanks a lot. Would you be able to show me how to make that grid system. Judging by my past post, I guess you can sort of tell that I have really no experiance in this stuff.

I understand what you are talking about though, the ones would be on, and the zeros would mean off, thus in lines they could be used to make pictures and words.

So if you could show me how I can set it up, preferably on the 16F628A, I would be forever greatful.
Any help would be appriciated.

-Omar

 

[HarveyH42]

I just started microcontrollers, almost two weeks now, but use AVR chips.

You can really save some time on the charactors, be pulling the data table out of somebody else's code (yeah, cheating, stealing, whatever...). Doesn't exactly have to be a POV project, could be for LED or LCD (custom charactors), something like that. Doesn't even matter what chip its for, or what language, just that charactors are 5 dots (bits) wide, and 7 high, which is very common.

There are several POV tutorials on the web, that go in detail about the how and why, so should be to bad figuring out how to use the data table you found. There was a good one for a propeller clock, and remember reading through one about bicycle spokes. Search on Hack-A-Day.com, pretty sure that's were I saw some of these.

 

[Omar.M]

Oh ok. Thanks a lot guys.
Do you have any examples of this datachart, what it looks like, I mean...
I know here it has one, now sure how I can extract it:

**broken link removed**
Thanks,
-Omar

 

[House0Fwax]

I'm not sure that I understand your question. But if you mean 'what would it look like?'. Then replace all the zeros with spaces and turn your head, then read it from top to bottom. The first bit is a square, and the second bit is the letters E C.

 

[Omar.M]

Ah

Ooh, I see now. Thank you very much!
So with that knowledge, I downloaded Great Cow BASIC because the language seems a little easier to grasp then C. So with it, I have been able to write a simple code, but I am not sure why it won't work. I am sure it is a mistake on my part, just it seems to compile correctly but won't program correctly.

Any ideas?

#chip 16F628A, 4

DIM A(4)
DIM A(1) AS BYTE
DIM A(2) AS BYTE
DIM A(3) AS BYTE
DIM A(4) AS BYTE

A(1) = 252
A(2) = 51
A(3) = 51
A(4) = 252

Start:

For var = 1 TO 4
Portb = A(var)
wait 8 ms
Next

goto Start

Thank you very much =)
-Omar

 

[audioguru]

Two summers ago, school kids wore big belt buckles that displayed a running LED display of their name or swear words. They were fairly inexpensive from China.
A guy told me they were a pain to program by pushing only a few buttons.

The many LEDs were probably multiplexed.
I didn't see any this year so the idea is dead already.

 

[Sceadwian]

The POV ones you wave at a camera are pretty much useless, as they only show up well on camera unless you want to try to sync it to a force sensor. They're more impressive if you do 'floating' clocks using a string of LED's spinning or bouncing back and forth like a pendulum in a half arc between two springs.