How to display dot on 7-seg , 4 digit


Closed Thread
Results 1 to 28 of 28

Hybrid View

  1. #1
    Join Date
    Feb 2003
    Location
    Salt Lake City, Utah USA
    Posts
    517


    Did you find this post helpful? Yes | No

    Smile

    I see - the PNPs (which I did not know about) threw me off. It appears proper for Common Anode.

    Try this:
    1) On your buffer, tie 1 and 19 low so they do not float.
    2) The 3rd from last line of your code - change "Return" to "Resume" (See manual section on On Interrupt for details).

    Please report back progress so that others following this can get closure.

    EDIT:
    3) Your lookup values need to be inverted - as written they are for common cathode displays. Change to ($C0, $F9, $A4, etc) where the segments you want off are high and the segments you want on are low.
    4) To turn on the decimal point on the second digit, insert right after the lookup table
    if i = 1 then Segments.7 = 0 (or if the DP is always to be on you could do this in hardware by disconnecting RC7 from D7 on U2 and connecting RD1 to D7 on U2 (in addition to RD1 going to the Base of Q2))
    Last edited by paul borgmeier; - 26th December 2006 at 07:15. Reason: add more info
    Paul Borgmeier
    Salt Lake City, UT
    USA
    __________________

  2. #2
    Join Date
    Jan 2006
    Location
    Istanbul
    Posts
    1,185


    Did you find this post helpful? Yes | No

    Default

    Here is the full list of Common Cathode:

    Starting from 0 to 9.

    $c0, $F9, $A4, $B0, $99, $92, $82, $F8, $80, $90



    ------------------------------
    "If the Earth were a single state, Istanbul would be its capital." Napoleon Bonaparte

  3. #3
    Join Date
    Feb 2003
    Location
    Salt Lake City, Utah USA
    Posts
    517


    Did you find this post helpful? Yes | No

    Smile

    Sayzer,
    You bolded Common Cathode as if it is for sure - you must mean Common Anode. Common Cathode requires the segment to be high to be on while Common Anode requires Segments to be low to be on. His buffer is non-inverting. (Your set looks correct though - I left a little for the OP to work out as a learning exercise but now he is close to set).

    EDIT:
    Oh, for thoroughness, have you considered testing DT's suggested gif animator at 1/4 scale?
    Last edited by paul borgmeier; - 26th December 2006 at 19:35.
    Paul Borgmeier
    Salt Lake City, UT
    USA
    __________________

  4. #4
    Join Date
    Jan 2006
    Location
    Istanbul
    Posts
    1,185


    Did you find this post helpful? Yes | No

    Default

    Hi Paul,

    My set is for Common Cathode.
    I now see what you meant.

    Let me check for Common Anode...Should be somewhere in my HDDs.

    BTW; I am just testing the animator and will remove it now. I think is is slowing down the CPU when there is more then one running.

    -----------------
    "If the Earth were a single state, Istanbul would be its capital." Napoleon Bonaparte

  5. #5
    Join Date
    Feb 2003
    Location
    Salt Lake City, Utah USA
    Posts
    517


    Did you find this post helpful? Yes | No

    Smile

    Sayzer,

    You have it correct for Common Anode in post #10 (at least the first three are correct - I didn't check your others). The OP should be grateful for your help because you probably saved him hours of work and frustration)

    Best Wishes
    Paul Borgmeier
    Salt Lake City, UT
    USA
    __________________

  6. #6
    Join Date
    Jan 2006
    Location
    Istanbul
    Posts
    1,185


    Did you find this post helpful? Yes | No

    Default

    Paul,

    Ok, here is the clarification.
    (from 0 to 9)

    Common Anode : $c0, $F9, $A4, $B0, $99, $92, $82, $F8, $80, $90

    Common Cathode : $3F, $06, $5B, $4F, $66, $6D, $7D, $07, $7F, $6F


    Using Dot or not changes from set to set.
    These are what I use.




    ----------------------------
    "If the Earth were a single state, Istanbul would be its capital." Napoleon Bonaparte

  7. #7
    Join Date
    May 2005
    Posts
    70


    Did you find this post helpful? Yes | No

    Default

    Hi paul borgmeier
    I'm not understand for item 1
    1) On your buffer, tie 1 and 19 low so they do not float.

    For item 4 , as you advise with modify some hard were right, Do you have other way with out modify hard or not.

  8. #8
    Join Date
    Feb 2003
    Location
    Salt Lake City, Utah USA
    Posts
    517


    Did you find this post helpful? Yes | No

    Smile

    1) On U2, pins 1 and 19 both must be connected to GND (or held low) in order for the input to be placed on the output of the buffer. If either pin is high, then the entire output of U2 will be tri-stated (high impedance). Floating means leaving pins NOT or unconnected, which is not good because they can "do what they want" - stay low, drift high, or worse go somewhere in-between. Just connect both 1 and 19 to GND and you will be set.

    4) The DP can be set entirely in software using the added line of code OR it can be set in hardware. If you cannot change your circuit, then use the software version. Just add the IF-THEN statement shown in 4) and you should have a DP turned on.
    Paul Borgmeier
    Salt Lake City, UT
    USA
    __________________

Similar Threads

  1. Hdsp 21xx display
    By Original in forum mel PIC BASIC Pro
    Replies: 5
    Last Post: - 7th June 2012, 20:07
  2. LED Machine Tach For Tired Eyes
    By Archangel in forum mel PIC BASIC Pro
    Replies: 33
    Last Post: - 27th January 2010, 14:55
  3. Single digit 7 Seg LED clock - PIC16F88
    By thirsty in forum Code Examples
    Replies: 4
    Last Post: - 17th July 2009, 08:42
  4. DS1820 display with 7-seg 4 digits
    By chai98a in forum Code Examples
    Replies: 12
    Last Post: - 10th April 2008, 13:12
  5. 7 segment digit problem (using Mister E's code)
    By jmgelba in forum mel PIC BASIC Pro
    Replies: 7
    Last Post: - 9th September 2005, 20:25

Members who have read this thread : 0

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts