Software Guys Are Funny Sometimes

Software Guys Are Funny Sometimes

Had a phun exchange with Rob @landley about, essentially, custom microcontroller based designs vs Arduino and Raspberry Pi.

My comments were that these (the so street creddy Arduinos and Raspberries) are great platforms, particularly for learning, even more, but as I said “the point is that you shouldn’t try hammering in a nail with a screwdriver”.

He said “And this is an argument for “the pc, Heh, don’t bother with that kiddo, lemme show you these punched cards”…”

Really? Discrete microcontroller designs have been obsoleted by the A-word and Pi gang? To the point that they are like punch cards? (not “punched cards”) I’m a bit confused, if that’s the case; why is it that firms like Atmel and Microchip have annual sales figures in the billions? And that “Freescale” (“Motorola” to grey beards like me still using “punched cards” (sic)) still produces numerous variants of the 68HC11? How about Intel’s 8051 family, that must’ve died out in the 80s?

Another funny Rob-o hat trick was saying my concern about radhard components in aerospace applications, was, “adorable”. If you don’t know what radhard is, check out this article for an idea. Obviously Rob has never been involved in the design of a system that included EMP resistance in the specs, nor appreciable lifetime in a geosynchronous orbit.

My whole point is this: Arduino and Raspberry Pi are great platforms, for hobbyists, makers, pros, whoever. Good stuff. But not the end all be all. Real world concerns come in to play, and they need not be as esoteric as EMP resistance. Buy me a beer sometime and I’ll tell you a cool trick for _trying_ to save a board during an EMP event. It involves something as punchy cardy as discrete BJT transistors.

Other real world concerns? Power consumption. Sure, you can make a doorbell out of a Raspberry Pi, but they consume 2.5 watts! Some really clever discrete microcontroller designs consume less power than a butterfly fart. Board size, compliance, environmental concerns (try designing stuff that goes on an automotive firewall, or for more phun, in petroleum drilling “down hole” applications); just some of the issues where off the shelf hardware may not meet your needs.

Right now I’m working with a client that wants to replace a proof of concept prototype made out of off the shelf modules (think Arduino and shields type thing) with a single, custom board. Why? Ownership of the design for one — that is important in some commercial applications. Cost is also a factor — much easier to populate and integrate a single board than a stack, and that means lower cost. Also when going to a custom board you can eliminate the parts you don’t want, and deal with your own design compromises rather than those of the module vendor. I’ve talked about all this stuff before.

The funny thing is I never came out against Arduinos or Raspberries. I came out in favor of them, but also educating those who come in to hardware by that channel that not all hardware solves all problems. Of course that’s something that “the computer is a black box” programmer types don’t get. They also tend not to understand the concept of “interrupt latency”, and think that everything processor should be ‘net connected and running an OS. Oh, and have never been involved with designing things that help keep people alive, or kill them. You know, some of the projects I’ve been involved with.

Here’s another phunny one. MTBF. Some projects I’ve worked on (typically .mil types) _require_ MTBF information for the hardware. Just for phun I did a search for “Raspberry Pi” and “MTBF”. This was the first article I found. Love the response “why are you concerned about MTBF? at the current prices, i’d buy several and replace as needed”. Yep, another live-in-the-basement software guy who’s never worried about hardware failing in orbit, underwater, in an operating room, battlefield, or race track. Welcome to my world, where hardware failure can mean death, not just having to (gasp) expose oneself to sunlight to bring a new box of goodies into the house. Otaku.

Best part of my day? When Rob-o said he was going to block me on teh twitterz because I was “pointless”. Good show all chap. These nice gentlemen disagree with you, since they are wearing some of my pointless, “punched card” discrete microcontroller nonsense that helps them identify team mates.




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