Blinkies!

Archive
1

Just received a package from one @ ransomhall! :smiley:

Now all I have to do is finish up the program for MADExpo so I can make some blinky lights for the demo room.

Wheee!

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Blinkies are working, thanks to @ ddurant’s awesome blog post:

Video of the blinkies:

[video=vimeo]44536912

Big thanks to @ ransomhall for getting these shipped in time for MADExpo! w00t!

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Awesome! I love that they’re demoed while still on the reel :slight_smile:

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@ devhammer - Disco man - very nice.

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nice, how come only few rounds were lit?

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They’re so tidy that way…a nice contrast to my desk at the moment. :slight_smile:

Anyway, I hate the idea of cutting them…I will eventually, since I have a project in mind that won’t work without cutting, but for the moment, I’m keeping them in one strip (per reel…I got two reels).

Can’t wait to show these babies off!

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That’s awesome! I wish I had ordered some now :slight_smile: . Can you post the code? I would love to see how you drive those baby’s .

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Dave Durant wrote a driver, which you can find here:

http://www.tinyclr.com/codeshare/entry/463

The code was written for NETMF 4.1, so I had to tweak it a little for 4.2, since it appears that some of the SPI stuff got moved around and a few of the constructors changed, but it only took me a few minutes to get it working, [em]once I realized that plugging everything into the output won’t work[/em] no matter how good the code is. :slight_smile:

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Nice! That is going to wow um at MADExpo

I was working on something similar http://www.tinyclr.com/forum/topic?id=7213

But did not get as far different chip Texas Instruments TLC5947 but I think the same sort of functions. I hope you do a nice write up on this as I gave up on this more confused than before I started.

I understand the theory of SPI but I am going back the the 101 stuff :slight_smile:

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Don’t assume that I understand it yet. Thankfully, Dave Durant posted code that works on 4.2 with only minor tweaks, so I didn’t really have to dive into the bowels of SPI to get the blinkies working. At some point, I’ll do a deeper dive on his driver class, and try to understand how it works. But for now what really matters is having Blinkies for MADExpo. :smiley:

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Micro .NET Blinkies!

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@ devhammer - glad you like them. Have fun next week.

I’ve been busy prepping for a local digital media festival (http://www.woodstockdigital.com) that kicked off today and goes most of the weekend. We’re turning a lot of local artists, makers, educators, and tinkerers into microcontroller maniacs :slight_smile:

For those patiently waiting for their blinkies - thank you. Once I finish spreading the local micro mojo, I’ll go back to being a postman.

For those who wished they had some - we’ll be doing another order at some point.

BTW - Adafruit has a great tutorial on how to properly cut these.

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@ ransomhall - If you do another order, please drop me an email in case I miss the post…I might well want to get some more if you can get the same deal. :slight_smile:

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@ devhammer - how are you powering these?

Why are only the first rows lite up? Power?

I want to play with some now! I need to come up with a project now.

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Dave Durant’s demo program allows you to choose the number of LEDs to control while the program is running. I think it defaulted to 64, so that’s why only part of the strip is lighting up. At full white, the entire 5m strip could draw as much as 10A, so given that I was powering off the mainboard power supply, I didn’t want to risk frying anything.

This morning’s project is converting a PC PSU over for use as a bench supply (adding posts for 12v, 5v, and 3.3v, and a switch), which should give me up to 22A to play with (hopefully enough to power the 2 5m strips I have).

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If you have the time - a blog post on that conversion would be helpful to someone like me.

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Here are the two tutorials I used:

There are some minor differences between them. I opted to put in a switch and a power LED (though for some reason my LED blinks when the unit is powered up…not sure what’s up with that). I ended up with only 5v and 3.3v, because I cut the 12v lines back to the PCB, before I realized what I was doing.

A couple of tips:
[ol]Leave more slack in the wire than you think you’ll need. I cut my ground wires too short and ended up having to pull them tighter than optimal to make the connection.
Make sure that you leave plenty of space around each of the binding posts inside the case, as you’ll be hooking up 2-3 ring terminals to each, and it gets crowded fast.[/ol]

Just tested the FrankenPSU, and it successfully powered two 5m reels, for a total of 320 RGB LEDs. Sweet!

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Thanks

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Great - glad I made something useful!! :slight_smile:

[quote=“devhammer”]…so I didn’t really have to dive into the bowels of SPI to get the blinkies working. At some point, I’ll do a deeper dive on his driver class, and try to understand how it works.
[/quote]
Trust me, once you look through the code and get it, you’ll be all “that’s it? really??”

The biggest help for these particular strips might be to get more details on the interface. All I could find for documentation was that you basically send the bytes for all LEDs, all the time, plus a few protocol bytes. For effects that don’t require all LEDs in the strip to change, especially on longer strips, it seems like it’d be a lot more efficient to have a way to just address the ones you want to change. Then again, SPI may be fast enough that it’s not really worth doing that. Dunno. Maybe ransomhall or GHI knows somebody that knows somebody who could provide more insight here…

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Trust me, once you look through the code and get it, you’ll be all “that’s it? really??”

The biggest help for these particular strips might be to get more details on the interface. All I could find for documentation was that you basically send the bytes for all LEDs, all the time, plus a few protocol bytes. For effects that don’t require all LEDs in the strip to change, especially on longer strips, it seems like it’d be a lot more efficient to have a way to just address the ones you want to change. Then again, SPI may be fast enough that it’s not really worth doing that. Dunno. Maybe ransomhall or GHI knows somebody that knows somebody who could provide more insight here…
[/quote]

Would be cool to get a better understanding of how it works.

For example, as noted, I got enough current from the FrankenPSU to drive 2 full reels, but it was pretty apparent that using 320 LEDs all at once had a significant negative impact on performance. Things are noticeably slower than when using just one reel, or part of a reel.

I also think I might add a button or some other means of switching the number of LEDs directly from the mainboard, as changing the value and redeploying is kind of inconvenient (not complaining about your code, just thinking about how I want to use it, demo-wise).

If anyone with more knowledge of the RGB LED strips would care to comment on ideas for improving performance when driving lots of LEDs, I’m all ears. :slight_smile: