Yeah, the 3.3V trick works ok for small numbers of LEDs, but if you've got a long strip you'll have voltage drop and the colors will look funny, probably brown/red, as the blue won't have quite enough voltage to work properly.
I believe the code can broadcast all pins or just one at a time. I haven't dug into this yet though. I've been trying to get the opc-rx server working, but I've had some issues. I've also noticed the rgb-test program occasionally glitches, so I think I might have some interference on my lines. On Wednesday, April 30, 2014 2:40:58 PM UTC-4, Mark A. Yoder wrote: > > Wow, that was really easy to make work. I didn't even use the 74HCT245. > I hooked GND to ground and the +5 to the 3V3 on the bone. I attached the > DI to P9_22 and it just worked! > > If I understand the code right, the data signal appears on several GPIO > pins as reported by pinmap.js. However I find it works on some, but not on > others. Have you seen this? > > Thanks for the pointer to the github site. The instructions made it > really easy to get going. Now I need to do something interesting with it. > > --Mark > > On Monday, April 28, 2014 7:10:16 AM UTC-4, Ian Woloschin wrote: >> >> Good news, one NeoPixel stick works :). Following the basic instructions >> found on Yono's LEDscape repository, combined with a 74HCT245N and I've got >> flashing NeoPixels run off my BBB. The important part is making sure to >> connect the 74HCT245 correctly, otherwise nothing will happen. Make sure >> that the BBB is on the Ax side and the NeoPixels are on the Bx side, and >> make sure DIR is +5V and /OE is 0V. Everything *should* just work after >> that. >> >> You may have luck with a different level shifter, but the 74HCT245 seems >> to be highly recommended by a bunch of people, so I went with that. >> >> My next step is going to be trying to implement some Python code to do >> the logic in my program, and use Yono's LEDscape code just to drive the >> NeoPixels. >> >> On Friday, April 25, 2014 11:16:52 AM UTC-4, Ian Woloschin wrote: >>> >>> Sorry, one minor correction. >>> >>> The dtb file should be in one of the following places: >>> >>> /boot >>> /boot/uboot/dtbs >>> >>> If you're using the latest Debian image then it's the second. I believe >>> Angstrom uses the first. It looks like the Yona-Appletree LEDscape readme >>> has been just been updated to reflect this. >>> >>> -Ian >>> >>> On Friday, April 25, 2014 11:12:10 AM UTC-4, Ian Woloschin wrote: >>>> >>>> I've been using a LEDscape fork that I think will better allow me to >>>> use Python to write the bulk of my program, and then LEDscape to do the >>>> Neopixel control. >>>> >>>> https://github.com/Yona-Appletree/LEDscape >>>> >>>> Everything works, except that you should check the uEnv.txt file in >>>> /boot or possible /boot/uboot to make sure you've put the *.dtb file in >>>> the >>>> correct place to be read. Different distros do different things, so it's >>>> hard to say exactly what you're looking for here. >>>> >>>> Unfortunately, USPS is late, so I won't have my Neopixel Stick before I >>>> leave this evening, so I won't be putting any time into this over the >>>> weekend, but I do expect to pick this back up early next week. >>>> >>>> -Ian >>>> >>>> On Friday, April 25, 2014 8:07:55 AM UTC-4, Yoder, Mark A wrote: >>>>> >>>>> Ian: >>>>> What instructions were you following? >>>>> >>>>> --Mark >>>>> >>>>> Sent from my iPad >>>>> >>>>> On Apr 25, 2014, at 7:21 AM, "Ian Woloschin" <[email protected]> >>>>> wrote: >>>>> >>>>> I'm an idiot. I blindly followed instructions that were likely for >>>>> Angstrom, and put the dtb file in the wrong place, /boot instead of >>>>> /boot/uboot/dtbs. Now that the dtb file is being read I've got >>>>> everything >>>>> showing up properly, which is great because I've got my first NeoPixel >>>>> stick arriving in the mail today. Unfortunately I'll be out of town this >>>>> weekend, but I've got a 4 hour train ride back Monday morning so I may >>>>> try >>>>> to get some stuff working on the train. >>>>> >>>>> On Friday, April 25, 2014 7:05:58 AM UTC-4, Ian Woloschin wrote: >>>>>> >>>>>> I'm looking into the same thing and running into the same problems of >>>>>> no simple tutorials. At this point I'm having issues getting the PRU to >>>>>> even be enabled, and I'm not really sure why. >>>>>> >>>>>> On Tuesday, April 22, 2014 12:59:09 PM UTC-4, Mark A. Yoder wrote: >>>>>>> >>>>>>> David: >>>>>>> Thanks for the pointer, however I had already Google'd around and >>>>>>> picked the LEDscape as the most promising. Since I haven't uncovered >>>>>>> any >>>>>>> 'getting started' guides for it I guess I'll just dive in a figure it >>>>>>> out >>>>>>> for myself. >>>>>>> >>>>>>> --Mark >>>>>>> >>>>>>> On Monday, April 21, 2014 1:48:15 PM UTC-4, dwfunk4475 wrote: >>>>>>>> >>>>>>>> http://lmgtfy.com/?q=beaglebone+black+ws2812 >>>>>>>> >>>>>>>> >>>>>>>> Plenty of tutorials . . . adapt to whatever pin(s) you wish to >>>>>>>> use on our BBB >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -david >>>>>>>> >>>>>>>> >>>>>>>> On Mon, Apr 21, 2014 at 11:00 AM, Mark A. Yoder < >>>>>>>> [email protected]> wrote: >>>>>>>> >>>>>>>>> Hi Beagle'ers: >>>>>>>>> I have a string adafruit NEOpixel LEDs[1] that I want to drive >>>>>>>>> with the BBB. LEDscape[2] looks like a good way to drive the LEDs >>>>>>>>> via the >>>>>>>>> PRUs. >>>>>>>>> >>>>>>>>> I'm not sure how to get started. Has anyone used this software >>>>>>>>> to drive the LEDs? What should I wire where? >>>>>>>>> >>>>>>>>> --Mark >>>>>>>>> >>>>>>>>> [1] http://www.adafruit.com/products/1376 >>>>>>>>> [2] https://github.com/osresearch/LEDscape >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to a topic in the >>>>> Google Groups "BeagleBoard" group. >>>>> To unsubscribe from this topic, visit >>>>> https://groups.google.com/d/topic/beagleboard/WvwfBq26kEk/unsubscribe. >>>>> To unsubscribe from this group and all its topics, send an email to >>>>> [email protected]. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>>> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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