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Project in motion

slotcarzslotcarz Posts: 30
edited 2005-05-18 20:50 in BASIC Stamp
Hi all..
Last week some of you may have saw my post on the LED display. Here is a couple of pics showing my progress and I really could use some help on it. I'm sure there is a formula for calculating resistor value. I have about 500 100 ohm resisitors and thought I could use them for this project? Maybe there is a better solution as to what the proper one to use is.
I guess I am at a loss as to how I need to connect everything. I have a BS2 on the way. I have purchased Max7219CNG drivers. The LED's will be common cathode·for use with the 7219 chips. Maybe I·should have read a book·or 2 before starting this project.·Any help anyone could give would be great as I am a good listener and can follow directions. I have searched for similar projects and or signs but nothing is available. Maybe just looking in the wrong places. I have also included my beginning schematic if anyone would like to push it forward a bit....
thanks in advance...

Jeff

Post Edited (slotcarz) : 4/17/2005 5:46:49 PM GMT
sign1.jpg
600 x 450 - 49K
sign2.jpg
600 x 450 - 53K
sign3.jpg
600 x 450 - 46K
firstschm1.jpg
800 x 579 - 29K

Comments

  • JonbJonb Posts: 146
    edited 2005-04-13 00:32
    http://www.luxeonstar.com/resistor-calculator.php

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  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-04-13 00:37
    Read the MAX7219 docs carefully -- current is controlled by it and you do not need inline resistors on the LEDs.

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    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • slotcarzslotcarz Posts: 30
    edited 2005-04-13 00:52
    Thanks for the replies..I am at the Maxim site and they really have some great info there...

    cya
    Jeff
  • LittlebuckLittlebuck Posts: 7
    edited 2005-04-13 11:03
    Your schematic looks a bit rough, but gets the point across. FYI you may want to check out PCB Express for free PCB and schematic Design software. Have fun
  • BeanBean Posts: 8,129
    edited 2005-04-13 12:46
    slotcarz,
    Check out the robometal, it's basically the same thing only on a smaller scale and done with SX/B. But the schematic and code are available on the Parallax website.

    www.parallax.com/detail.asp?product_id=28099

    Bean.

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    "SX-Video Display Module" Available Now.

    www.sxvm.com

    "A problem well defined, is a problem·half solved."
    ·
  • slotcarzslotcarz Posts: 30
    edited 2005-04-14 02:02
    thanks for the extra links... I wanted to test my max7219 chips using the PC method described in the Fig.1 diagram on the Maxim site and if anyone knows which resistor I am suppose to use for it. It shows a 4.7K but is it 1/4W or 1/2W, just wanted to be sure.
    here's the link if anyone knows...
    http://www.maxim-ic.com/appnotes.cfm/appnote_number/2782

    thanks again for all the help!
    Jeff
  • KenMKenM Posts: 657
    edited 2005-04-14 03:42
    1/4 watt
  • allanlane5allanlane5 Posts: 3,815
    edited 2005-04-14 13:23
    Yes, the resistor on the MAXIM 7219 only tells the MAXIM how much current to use for the max brightness -- I don't think any major current actually goes through it. And you can tell the MAXIM to dim the LED's, which it does using its own pulse-width-modulation scheme.

    By the way, really neat picture. What is the time between the first "puddle of LED's" and the mounted version?
  • slotcarzslotcarz Posts: 30
    edited 2005-04-14 22:51
    thanks for the info on the resistor... It was about 1 1/2 weeks to complete, working about 2 hrs at a time. Now I have to solder leads to everything and that will be fun in itself... :]

    cya
    Jeff
  • slotcarzslotcarz Posts: 30
    edited 2005-04-15 23:42
    Will the power supply of 6-9 V on the BS2 be enough to power the 6 MAX7219's I will need for this or will I need to power the chips seperate to run the LED's.. I received my BS2 today and now the fun can begin... well I hope...

    cya
    and TGIF!!!!!

    Jeff
  • slotcarzslotcarz Posts: 30
    edited 2005-04-16 03:29
    found the answer...
    thanks..
  • slotcarzslotcarz Posts: 30
    edited 2005-04-17 03:48
    Ok my way isn't working so it looks like I am not a schematic reader, well to a point. In the picture I posted in this reply. What are your thoughts?

    In the digit line, will all the positives go to the digit·connection of 1,2,3 etc.? (green line)

    In the seg line, will the negatives go to the seg connection of 14,15,16 etc.?( purple line)

    I am trying to follow the schematic that Bean posted since that is the closest I have found for my project. My sections will be 7x8 since I have not put in the 8th Led in each column. I think the digits will work better being 7 high. I have the first section soldered up and looks like it is coming apart since the lights all light up with the battery power connected and no signal from the BS2..

    thanks...

    Jeff

    *************

    completed and fixed

    Post Edited (slotcarz) : 4/22/2005 12:17:19 AM GMT
  • slotcarzslotcarz Posts: 30
    edited 2005-04-20 02:56
    Hi all. Little update on things.
    Had to redo my first section of LEDs since I botched it. I just wired up the first 7x8 section. Have been putting the code together and actually got it to work, well sort of.

    I guess I need to look into the max7219 further as I cannot shut off all the LED's to scroll my letters. Could someone help on that? They all come on and the stamp resets and I can see something scrolling but with all the lights on just can't make them out.. Hey I even got a thumbs up from the wife with my project..even though she thinks i'm cookoo for coco puffs..
    thanks!
    Jeff
  • BeanBean Posts: 8,129
    edited 2005-04-20 11:13
    Jeff,
    Please post your code.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video Display Module" Available Now.

    www.sxvm.com

    "A problem well defined, is a problem·half solved."
    ·
  • slotcarzslotcarz Posts: 30
    edited 2005-04-20 21:14
    I'll post it when its ready.

    thanks

    Post Edited (slotcarz) : 4/22/2005 12:16:13 AM GMT
  • slotcarzslotcarz Posts: 30
    edited 2005-05-18 20:50
    I think it has been over 2 months since I started this project, well gathering and such. I have included what is finished in a small video. I completed the wire transfer of the LED's. I do not have code for it. I have been using the code for testing from the N/V article and have come to an end of the road.
    If there is someone who could write or help with certain aspects of it, that would be great.
    What I would like the sign to do is scroll the word and number of this:

    "Hit the Jackpot and Win $xxxx"

    x being the amount of the progressive on my slot machine. It's all for fun.


    Video File· --


    I do not have the grasp on how to write the code·to·scroll thru each segment and I think thats where my problem is.

    I have been reading thru the manuals, docs, whatever I can find, but never the right answers. I cannot get the LEds to scroll thru all the led's except for their own segments as you can see in the video. The code was readable the first 3 segment but after putting in different things to try it just doesn't want to cooperate.
    I guess the project will be put on hold since my wife and I are leaving the country this Monday to go see our future child we are adopting and won't have time for this right now. That is the highest priority.

    I wanted to thank all that have helped me to this point and this is a great site with a great bunch of people.

    Hopefully I can get back on track with it...

    take it·easy all...

    Jeff


    Post Edited (slotcarz) : 5/20/2005 8:34:34 PM GMT
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