On Tue, 30 Jun 2015 15:47:27 +0300, you wrote: >Well, I get that BBB is a lot more powerful than Arduino (UNO) and I have >no doubts about that. Frankly speaking, that's the reason I am into this >BBB kind of thing. I was wondering if I could *reuse* my arduino uno >compatible sensors i.e. with BBB. That would really be a kick start for a >beginner like me.
Arduinos are designed as a 5 volt system, which means that the peripherals are as well (the shields). You can't connect them directly to the processor, not when the shield is powered from 5 volts. Some chips and chipsets on the shield may work at 3.3 volts. Those can be directly connected to any pin except the ADC pins. If the chips only work at 5.0 volts, you will need a level shifting chip (see level translators at TI.com). Series resistors do not work, it's not a matter of current, it's a matter of voltage. Use a chip. you might be able to use a resistive voltage divider, but it will cost you speed. Best to use the chip. This does not address ADC pins. The A/D pins on a MEGA are good for 0 to 5 volts. On an XMEGA, good from 0 to 3.3 volts. 5 or 3.3 being the nominal supply voltage, don't exceed VCC on the chip. The ARM processor pins are good to a maximum of 1.8 volts. You'll have to adjust that, too. What I'd suggest (and there might be one, or you'd have to design it), would be a cape that does level translation and ADC buffering (op amps, but don't run the op amp from more than 1.8 volts and make sure it will do rail to rail on the outputs). The cape can have pinouts for the arduino shield. Even then, you have to pick which pins will be inputs and outputs, since most chips do groups of 8 or 16. There is a 1 bit level translator, though. the level translators will go from almost any voltage up to 5.5 to any other voltage up to 5.5... They'll go both ways. Harvey > >And which programming language would be best. I know C only and trying to >learn Python on my own. I am open to any suggestions. > >On Tue, Jun 30, 2015 at 3:53 AM, Bruce Boyes <[email protected]> wrote: > >> The BBB is quite a different beast from Arduino (and there are many of >> those; I assume you mean one of the simpler ones such as 'Uno'). Arduino is >> simple to use, like a bicycle. It's great when that is what you need. BBB >> is more like a powerful motorcycle - lots more capability but a step or ten >> up in complexity... and learning curve. BBB has a pretty complete operating >> system capability (I use Ubuntu 14.04) which the simpler Arduinos lack. BBB >> has ethernet, HDMI, etc baked in which Arduino does not, and the simpler >> Arduinos can't realistically add that. The more complex Arduinos can, but >> then you get to about the same price point as BBB and you arguably have a >> kludge. I don't mean any of this disparagingly, just that the "best" >> solution for you depends... on what you are trying to do, and a lot of >> other factors. Personally I like BBB for some applications where you want >> Linux, HDMI, Python, etc, and Teensy 3.1 for smaller ones. They are all >> tools - pick the one you like best or that fits your needs best. >> >> You'd hope, this being 2015 (and not 1995) that there would be some *standard >> and portable* way to have hardware device drivers you could use anywhere. >> There are some efforts in that area such as Pingo >> <https://pypi.python.org/pypi/pingo/0.1.9> but this issue is gnarly... >> figure out a good solution and you'd have a great business. The use of I2C >> and SPI as common hardware interfaces has helped a lot but there is a long >> way to go until all sensors could be "plug and pray" on any hosting system. >> >> BBB also has the PRUs <http://elinux.org/BeagleBone_PRU_Notes> which seem >> like a solution for any number of special realtime interface issues. And >> the BBB community is pretty great too! Mr Kernal, Robert Nelson >> <https://github.com/RobertCNelson?tab=activity>, and Mr Beagleboard >> (Gerald Coley) and a ton of others are working hard to make BBB great. >> Adafruit is also a good source of BBB parts and tutorials >> <https://www.adafruit.com/category/75?gclid=CjwKEAjw2cOsBRD3xNbRp5eQxzYSJADZGYbzr3b7SK924RUB0eE7SegsUotk-6NzpIrehZ9pKqCdXBoC1qDw_wcB> >> . >> >> Welcome to the community! >> -- 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]. For more options, visit https://groups.google.com/d/optout.
