LDP8806 RGB LED Light Strip

[longpole001]

i am sure you found this info , but ill will post it anyways

https://github.com/adafruit/LPD8806

[cncmachineguy]

Actually I didn't find that cuz generally I skip over any result that doesn't look like an actual datasheet will be there. But upon following your link and reading several threads, I have come to realize there is no available datasheet for this chip - at least not in english. So it looks like there are 2 choices - port the duino code to PBP, or play guessing games with the part. Assuming it has 4 connections, I would assume that it is an I2C interface.

If this is the case (which you may be able to verify by pouring over the duino code to find the actual method called to talk to it), you can just set up some loops to start sending address/data to see if anything happens. My guess would be an address for each chip maybe then some data describing the color. So I would start by sending FFh to all 127 address's 1 at a time then see if the LED's light up. If none do, try different data going through the entire address selection again.

Not sure if this is helpful or not, I hope it is. Also I hope I don't come off sounding like a smart A$$ - I do not mean too if I do.

[m_flfl]

lpd8803-8806-8809--lpd6803-lpd1101 all the same

[m_flfl]

http://arduino.cc/forum/index.php?PH...&topic=83073.0

[Atom058]

Hello Everyone - Thanks for your posts. I am sorry that I droped out of this, but I am now in Mexico dealing with a family illness. In my spare time, I have scoured all the forums, blogs, posts that I could find and I finally came across some obscure post that broke the ice for me. I will explain what I found... For the LDP8806 LED strip, the thing that threw me off was that there was no "latch" pin. Just 4 wires: +5V, Gnd, Data and Clock. At first, I thought it was I2C, but that did not pan out. I then discovered that you have to send 3 bytes for each LED on the strip (using SHIFTOUT). 1 byte for each of R, G & B. If you want the particular LED to be turned on, the high bit (bit 7) should always be set to 1. The remaining 7 bits will determine the brightness of that LED (that's the nice thing about this chip is that it has built-in PWM). So, if you sent an LED a %10000000, you would activate that LED, but it would be set at 0 brightness (off). Send %11111111 would be on at full strength. OK, lets say you have a 1M strip. That will have 32 RGB LEDs on it and you want the output to be white. You would send:

GreenLED = %11111111
RedLED = %11111111
BlueLED = %11111111

for icnt = 1 to 32
shiftout dp1, cp1, 1, [GreenLED/8, RedLED/8, BlueLED/8]
Next

That loads all of the LEDs on the strip with the information. Now here's the jewel... To get it to latch (display), you send 3 %00000000's (SHIFTOUT DP1, CP1, 1, [%00000000, %00000000, %00000000]) one time and that gets sent down the line and you now have a bright white strip. That is pretty much it. Now you can use your imagination and get all kinds of cool effects - I have! Hope that helps! Have fun! Jeff

[cncmachineguy]

Good stuff Jeff, Thanks for clearing this up!!

[daza25]

i am sure you found this info , but ill will post it anyways

https://github.com/adafruit/LPD8806

Thanks for that link, that's been very helpful.