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 Peggy 2.3 problem: D16 to D24 are darker (updated)
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By: Anonymous: JEROME () on Wednesday, April 07 2010 @ 01:38 PM PDT (Read 26888 times)  
Anonymous: JEROME

Hi all,

I've just received my Peggy 2.3 kit and I have solder all components and started to sold LED. I've tried powering the kit with 6 rows of LED. The problem is that all LED are bright except D16 to D24. It seems not to be an IC problem because I exachanged them with the same result... Any idea ? Soldering problem ?

I have alse tried to play with the dimmer but with no visible results (even if I tried turning the dimmer 20 times).
Thanks a lot for any kind of help.
Jerome





       
   
By: Windell (offline) on Wednesday, April 07 2010 @ 02:05 PM PDT  
Windell

Is it really the case that you just received a new one and are having the same problem with a different Peggy, or are you just reporting the exact same problem as before, as though it were a new issue?

If you'd like technical support, I'd suggest reading and replying to the responses to your posts. If instead you'd prefer to just keep posting the same questions as though they were new, it won't really do much good.






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By: Anonymous: JEROME () on Wednesday, April 07 2010 @ 11:51 PM PDT  
Anonymous: JEROME

Not it is the following of the problem I already have but for a strange reason I didn't succeed to post a reply so I tried a new post.
If it is the same problem this is not exactly the same condition as I solder 6 RGB rows now and all are OK except (as before) D16 to D24 leds.
You know all, could you helps ?

Thanks a lot for any idea.

Best Regards
Jérôme






       
   
By: Windell (offline) on Thursday, April 08 2010 @ 12:32 AM PDT  
Windell

Are you only building 6 rows, or are you going to continue to put LEDs in the Peggy?


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By: Anonymous: JEROME () on Thursday, April 08 2010 @ 04:50 AM PDT  
Anonymous: JEROME

I will put all the rows but as I have so very few time for the moment I solder progressively all the LED, I need some calm not to make a mistake with RGB order... I am soldering from upper left of the peggy 2 board toward the bottom right. I have already soldered 1/4 of the total amount of LED.
It seems that you prefers me to solder all before replying to my question? Right?

Thanks anyway !
Jerome





       
   
By: Windell (offline) on Thursday, April 08 2010 @ 09:43 AM PDT  
Windell

>It seems that you prefers me to solder all before replying to my question? Right?

I prefer that you follow the build instructions. It sounds like you're trying to adjust the brightness before you finish step 10 (adding the LEDs).


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By: Anonymous: project2501 () on Monday, April 19 2010 @ 03:55 PM PDT  
Anonymous: project2501

Hello,

I'm sorry to invade on this topic, but it appears I might be having a similar problem with the Peggy 2.3 board that JEROME is having.

I've soldered in all of the LEDs, and also added the optional buttons with pull-up resistors. All of the programs I have written and uploaded to the board (as well as all of the test programs) work great except for one minor issue.....

The only problem I am having is that when there are several LEDs lit up on row 5 to the left of column 16, all of the LEDS from columns 16 to 24 on row 5 (D516-D524) turn off. This problem seems to come and go as I run the board for a while, but it is especially apparent when I try and run the LEDs at a lower brightness level. When I run the LEDs at a lower brightness, several adjecent rows experience the same behaviour as row 5 does. Note: I am using 3 D-cell batteries and not the wall socket.

I've tried to go through the circuit with a multimeter and check to see if there is a short, but I haven't found anything as of yet. Do you have any connection points to suggest to check? (or other things?)

I've added some pictures to (hopefully) make it more clear:





Thank you very much for your help, Windell.





       
   
By: Windell (offline) on Tuesday, April 20 2010 @ 12:12 AM PDT  
Windell

Well, that looks and sounds like a real problem indeed.

A bit about your configuration first:
- Serial mod or P2 compatible?
- Exact model of LED driver chips in your kit (e.g., STP16DP05B1R)

This *feels* to me like a problem that can be fixed in software. The symmetries of the hardware shouldn't (in most cases) allow something to just affect part of the rows over part of the columns like that, so there's probably a bug in the library. It would be helpful to know those additional details about your configuration before going to the next step.

Would you be willing to try out a test program or two to help debug this?

(Obviously unrelated to the problem, but I feel obligated to say it: pull-up resistors are generally unnecessary on the buttons because the internal pull ups are sufficient for nearly all button-use cases.)


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By: Anonymous: project2501 () on Tuesday, April 20 2010 @ 10:16 AM PDT  
Anonymous: project2501

-My board is set to be P2 compatible
-Exact model of driver chips is STP16CPS05


I am certainly willing to try out a test program or two.

I wrote before that it seems to be influenced by the number of LEDs lit up in the same row, this video might help a bit in diagnosis:
http://www.zshare.net/download/75183508a1bcea07/
It is a simple modification of the PeggyWriter program found on google code, so that it just scrolls many "E"'s across the display from right to left.

Also, I was unaware that the internal pullups would be sufficient (i'm not very experienced with electronics). Should I desolder the resistors (5000 ohm, as specificed in the circuit drawing), or is it okay with them there?





       
   
By: Windell (offline) on Wednesday, April 21 2010 @ 01:42 AM PDT  
Windell

Thank you for the additional information; this is good detail.

Notable features of this bug:
Peggy 2.3 / P2 option
Battery power
STP16CPS05 chips
Standard "Peggy2" library or derivative programs
Yellow LEDs

Jerome: If you're still listening in here, how does this compare to your setup?


As for the pullups, it shouldn't do any harm to leave them there. If you do decide that you want to remove them, I always suggest clip rather than desolder; it's fairly easy to damage a pcb by soldering-- especially on that thick one.


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By: Windell (offline) on Wednesday, April 21 2010 @ 01:44 AM PDT  
Windell

A good first test program to try would be one that uses a different style of driving the LEDs. I'd suggest trying out the "Peggy 2 RGB" program, to see how that behaves:

http://www.evilmadscientist.com/source/Peggy2_RGBdemo5.pde


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By: Anonymous: project2501 () on Wednesday, April 21 2010 @ 09:32 PM PDT  
Anonymous: project2501

I tried the RGB demo multiple times, and have had it running for about 15 minutes and I have seen no sign of issues (video below):
http://www.sendspace.com/file/clmhv3

I also recorded my board running the peggy2_firstdemo.pde program. The beginning is the only interesting part, as you can clearly see how those certain rows do not light up, my board runs the rest of the program with no issues (video below):
http://www.sendspace.com/file/0xmlgb

You might notice that one of the LEDs looks a bit "bent", this was not caused by the board being dropped or damaged, I simply soldered it in that way and did not notice that it had slipped out a bit before I soldered it. I don't think that LED should be causing any issues, I will replace that LED later, but I wanted to solve the issues I am having with the board first before doing any potentially damaging desoldering.





       
   
By: Windell (offline) on Wednesday, April 21 2010 @ 11:27 PM PDT  
Windell

Okay, now let's try turning on a few more LEDs in that same program.

Find the line that says: w =0; and change it to w = 15;

See what happens. (I don't need to see a video-- just tell me what you see.)

A "bent" LED can usually be fixed by melting the solder pins on the back and *carefully!* pushing it into place. Try to avoid desoldering when possible. Big Grin


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By: Anonymous: project2501 () on Wednesday, April 21 2010 @ 11:58 PM PDT  
Anonymous: project2501

I changed w =0 to w =15 and uploaded the program, the board still fuctions properly, just there are more LEDs lit up now.





       
   
By: Anonymous: project2501 () on Thursday, April 22 2010 @ 12:03 AM PDT  
Anonymous: project2501

By "just there are more LEDs lit up now", I meant that there are more LEDs lit up as expected, scrolling through the different patterns with the Off/Select button still works fine too.





       
   



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