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keith726

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  • keith726 followed jbumstead1 year ago
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  • keith726 commented on Hyper_Ion's instructable Custom NeoPixel Rings From Scratch! 1 year ago
    Custom NeoPixel Rings From Scratch!

    Mero55, you are correct (I guess it pays to read the data sheet - duh!). I never heard about this method of transferring data, and it's REALLY cool. Just send out a bunch of 24-bit strings, and the first neopixel ( which had 3 leds) grabs the first 24 bits, then retransmits the string of bits minus the 24 bits that it used. The next neopixel grabs the second set of 24 bits, keeps those 24 bits for its leds, then passes the remaining string of 24-bits down the line to the next leds. This way, you're not addressing pixel 1, 2, or 3 - you're sending as many 24-bit "packages" as you have pixels, and the pixels are wired in series. Each pixel grabs the first 24 bits available to it, keeps those for its own use, then retransmits the REMAINING 24-bit packages down the line to the ne...

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    Mero55, you are correct (I guess it pays to read the data sheet - duh!). I never heard about this method of transferring data, and it's REALLY cool. Just send out a bunch of 24-bit strings, and the first neopixel ( which had 3 leds) grabs the first 24 bits, then retransmits the string of bits minus the 24 bits that it used. The next neopixel grabs the second set of 24 bits, keeps those 24 bits for its leds, then passes the remaining string of 24-bits down the line to the next leds. This way, you're not addressing pixel 1, 2, or 3 - you're sending as many 24-bit "packages" as you have pixels, and the pixels are wired in series. Each pixel grabs the first 24 bits available to it, keeps those for its own use, then retransmits the REMAINING 24-bit packages down the line to the next pixels. Brilliant!In essence, each neopixel has a 24-bit shift register in it, but instead of transferring all the incoming data to its output (typical shift register "overflow"), this device essentially switches the input string of bits to the output (to the next pixel) as soon as its 24-bit register is filled.

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  • keith726 commented on Hyper_Ion's instructable Custom NeoPixel Rings From Scratch! 1 year ago
    Custom NeoPixel Rings From Scratch!

    How do the LEDs know the position of each LED in the strand? When you assemble individual LEDs, how do you address each one individually?

    Hyper_ion, That makes perfect sense. I'm very familiar with shift registers, and I think you are correct. I didn't think of that. Do you have to input the total number of LEDs in your strand somewhere in the software? That would imply that your reasoning is correct. By the way, have you ever tried to get a technical answer from Adafruit? I've had no success - I guess they're too busy to answer thousands of questions from newbies. And their document on using neopixels, while excellent, does not explain HOW each LED is addressed.I like their products - I have one neopixel 6" semi-circle that I haven't tried yet. I've wondered how you could make your own strips with individual LEDs and then address each one. I believe that you're correct - shift registers! Thank you so much for takin...

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    Hyper_ion, That makes perfect sense. I'm very familiar with shift registers, and I think you are correct. I didn't think of that. Do you have to input the total number of LEDs in your strand somewhere in the software? That would imply that your reasoning is correct. By the way, have you ever tried to get a technical answer from Adafruit? I've had no success - I guess they're too busy to answer thousands of questions from newbies. And their document on using neopixels, while excellent, does not explain HOW each LED is addressed.I like their products - I have one neopixel 6" semi-circle that I haven't tried yet. I've wondered how you could make your own strips with individual LEDs and then address each one. I believe that you're correct - shift registers! Thank you so much for taking the time to reply. Keith726

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  • keith726 completed the lesson LED Strips in the class LEDs and Lighting Class3 years ago