Furthermore, how about putting a byte after the address byte with the length of the "frame" (and I use this term loosely) using the BBB as master (for collision avoidance, I mean) with each MCU only speaking when spoken too? Just thinking out loud lol.
On Monday, January 30, 2017 at 5:55:06 AM UTC-7, woody stanford wrote: > > I'm of the opinion that a lot of the terminology being used is being > mixed, slurred, shifted in such a way to make basic concepts difficult to > understand. I thought I would just talk about it. > > What is SPI? You can use the terms UART and SPI interchangably. Bear with > me on this...my point is cultural. SPI is ***serial***, asynchronous (in > that it doesn't require a clock line, it uses timing purely) and 0V meaning > zero and +5V meaning one (TTL). That I suppose you can have SPI use +3.3V > to represent one is acceptable. > > This whole idea about SPI "throwing ioctl errors" is preposterous based on > the previous. SPI is generated by a UART, a chip, a piece of hardware (that > you can code a software UART not withstanding). SPI is the protocol that is > the raw output of a UART. > > I2C is understood to be (1) a protocol that uses a clock signal in > conjunction with a data line, and (2) has something to do with being able > to multiplex several "peripherals" at the same time with allusions to being > the little brother of RS485. And no one really knows what CAN does, only > that it is there and is comforting to know that you can connect as many > things to your CPU as you could possibly conceive. It is a mystery lol. > > That we are being held hostage by electrical engineers and the whole > microcontroller community does in no way change the fact that the BBB is a > true UN*X host. Its just the way that it is. > > Which leads to the inevitable question, why this ambiguity regarding the > correct procedure to configure and utilize the P8 and P9 connectors. This > is a TRIVIAL issue on a microcontroller. You just set the configuration > registers such and communicate. Why this ambiguity on the BBB, whether real > or perceived? I suppose that someone in authority at Beagleboard has to > settle the issue for the prime path to success in using the P8/9 > connectors. This ambiguity is killing me. Does libpruio do it? I don't know > :) > > My understanding of it is thus (and I'm sure its inaccurate and I beg > someone to definitively explain it better so that I might understand), that > it is a combination of a systems administration task combined with a > programming task, that both must be done in order to unlock the potent > connectivity powers of the BBB's P8 and P9 headers.That the crux of the > issue is two fold, that I must add some lines to various configuration > files so that it activates the ttyO1 thru ttyO6 "terminals" which allows > civilized serial (and other communication like GPIO) to happen. My > instincts tell me that this pertains intimately to the UN*X concept of a > "stream", a concept of power and thus an element of our UN*X faith. > > Is this so? And if not, how is it? Is my question to the minds greater > than my own. > > Thenwe use such programming concepts such as fopen() and open() to > communicate with ttyO1 thru ttyO6 providing abstraction yet nimble, > universal connectivity. > > Thoughts? > > > -- 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 beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/bce1a27d-758a-4a25-b7c2-1e99cb748092%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
