Wednesday, August 26, 2009


I consider myself a fairly well-rounded engineer. My specialty is control systems but that's in name only. It doesn't say embedded systems on my MS diploma because I had already taken all of the embedded classes for non-grad credit. It says communications on there because I sat through all of the comm classes (and got A's in them) but even though I know a lot I wouldn't consider that my bag. It doesn't say 'math minor' on my BS degree because I was two classes short (I decided to get a head start on my MS instead of the math minor). I've been programming since I was 6 in BASIC, C, Perl, Python, etc. That doesn't make me a CS major, but the years after that of learning to use source control, taking OOP classes, using unit tests and documenting with Doxygen makes me at least a friend (you guys will be my friend, right?). I built robots when I was a teenager and learned the basics of electromechanical systems as a controls engineer, so I'm claiming some mechanical experience as well. And I can speak German.

But I find as I grow older that some areas I just don't know about. Worse, I think I've built them up so that they seem so difficult that it's not worth it to even try to learn about them. TCP/IP, networking, ethernet - all that is something I've been interested in but thought the barrier to entry was too high. I've fussed about around the edges - I can tell you that the ethernet physical layer uses differential signal and (I believe) a 350MHz signal. I've done web programming and that introduced me to ports and such, but I don't take the time to go and just learn the stuff. I would start and I'd see the 7-layer OSI model and my eyes would just glaze over. Who the hell needs 7 layers (unless it's lasagna)? What are they cramming in there that it NEEDS 7 layers. Is it really this complicated to send data across the internet? I deal with microcontrollers and RS-232. I can send data that way, but for some reason people see the need to make twittering power meters out of the same microcontrollers. Other than being just a foolish idea it seems way too complicated if you have to interpret every layer of this 7-layer monstrosity just to do something as asinine as say 'Your refrigerator is now using 78 watts of power!'

So I figured I wouldn't deal with it. Who needs internet connectivity? I'll get along just fine. But still, it vexes me. It's something I don't know. I have a friend who does all this sort of stuff, makes routers in his free time. So I ask him 'What do you DO? What do you know that I don't know?' And he replies 'I can tell you exactly how a machine responds to a ping request. Where the message goes, where it comes from, what happens. It's complicated but I know it.' Basically, he knows how the OSI model works, what each level does, what happens. And the trick is it's mostly programming after a point. But not straightforward programming: complicated CS-type programming. Layers of abstraction built upon layers of abstraction so in the end you don't know that you're dealing with bits and voltages. You see, software people are TERRIFIED of bits and voltages and they will do anything they can to abstract those away. They have sacrificial programmers that write drivers to interface the bits and voltages to sane, reasonable things like floats and strings. They'd have a minor episode if they saw a character instead of a string. They NEED the 7-layers of the OSI model to be able to effectively ignore the basic truth of what's happening: bits are being represented by voltages. By the time you get to the 5th layer you're dealing with all kinds of structs, connection IDs, sessions and voltagephobia so that you don't know what's going on. If you're me that is.

If he tried to explain it all I think I wouldn't have understood. He could have explained it in Elvish and it would have made as much sense. So I ignore it again BUT IT STILL BOTHERS ME. Especially since I designed what I thought was a very complicated, nice and worthwhile messaging system for microcontrollers built on top of RS-485. It had circular buffers, message queues, priority, timeliness, guaranteed message delivery and all that jazz. It was complicated but I just started at the bottom and worked up. Pretty soon *I* had a few layers just to implement serial communication between a couple of devices. You had to have addresses and ACKs and collision sensing and much more to handle all this. It gets complicated quickly. Even when you start simple you always have the edge case. "Oops, what about this? Better add an address field. Oops, better add parity. Gotta ACK that for sure.."

It adds up. So I thought I might take another crack at TCP/IP and you know what? It turns out it's a bunch of things I already know. Just more queues and buffers and ACKs. When a ping happens (I think this is how it goes...) it's sent to the right computer (as determined by its IP address) where the network layer reads the message, finds it's an ICMP ping packet and puts the information in a special struct then pushes it into a queue for the ICMP handling process to take care of. When it gets around to it, it creates a response packet, tells the network layer where to send it (what IP address) and puts all that data into another struct and pushes it onto a queue for the network layer. That's it. Not too complicated - just data structures, processes and lots of teamwork. I learned something about TCP/IP.

TCP/IP is a complicated system, there's no question. But it does a LOT. It can reliably send data halfway around the world to a computer you didn't know existed in a few seconds. That sort of success is built up on layers and layers of success - each layer being tested and battle-hardened until it has so many special cases that it looks like an insane asylum. But once again - IT WORKS. Simpler systems would not. I don't begrudge the creators of the magical internet their seven layers anymore. It's not simple but it's not incomprehensible. It uses tools and methods that I was aware of - I just wasnt' aware of how they pieced them together. Now I am. The moral of the story is that if there's something you want to learn or need to learn don't think that it's impossible just because it's complicated, and don't condemn the creators of the system just because it's complicated. Just take it slow, re-read a lot and eventually it will make sense. Eventually.

Thursday, August 20, 2009

Content or Not Content?

That title up there is actually a clever double-meaning. I'll get to those meanings in a second. Suffice it to say I'm smart and it makes me feel smarter to withhold information from you for a few minutes longer. It won't be terribly long, so just bear with me.

I've often heard that writers can't write if they're happy. After all, how boring is happy? Have you ever imagined yourself perfectly content with not a care in the world? How long did you keep imaging that before it you moved on to something more interesting? It takes me about five seconds. I imagine myself sitting in a chair with a smile on my face and... then I repeat that. Forever. That's dull. Writers know this either consciously or subconsciously and strive to keep themselves aggravated. After all, writing is about conflict. Protagonists, antagonists, twists, man vs. man, man vs. nature, man vs. God, etc. So it doesn't do to live a life of contentment because the more conflict you're familiar with, the more you have to write about. Those writers make good books (in case you didn't catch it, the first meaning of the title was 'content' as in 'the opposite of conflicted').

So perhaps I can take it as an indication of my level of contentedness that I don't write here much. That's actually incorrect or at least a confusing argument. For instance, what kind of content could I put here? I started this blog to detail cool ideas I had and hope that other people would say 'wow, that's neat! I didn't know you could do that!'. I have some of those. From time to time. But my day-to-day work isn't exactly to work with super-awesome ideas all the time. It's somewhat hard to breed super-awesome ideas ("Hey guys, let's make robots with neural networks that train themselves to efficiently compete for limited resources against other robots!") when the only ideas you work with are super-pedestrian ("Hey guys, let's use Labview for test software again! All right! Just like the last 50 times! High-Five!"). Now the total contents of this blog are by no means all of the super-awesome ideas I've come up with, but it's enough of them. What I DIDN'T want to do with this blog was to 1) whine about my life and how horrible it is, 2) just post links to cool things OTHER people have done and 3) update about how I haven't had time to update.

I hate whining. And my life isn't awful or even excessively boring. What's the worst thing that happened to me lately? I had a fight with my wife this morning. Sure there was yelling. Sure there was screaming. Sure I kicked a robot (poor Roomba!) Sure we were angry. So what? That's not bad, that's a fight. That's a normal fight. I'll tell you what we didn't do. We didn't threaten to leave each other. We didn't say things like 'My ex-girlfriend never did this to me! That's why I like her much more than you!' We pushed each others' buttons and eventually apologized to each other. Wow. I'll tell you the number one thing I fear is getting in fights with my wife, but that's not the worst thing in the world. And how boring is my life? Well today I had to go through my Labview sub-VIs and re-arrange the connections one-by-one. I have about 20 of them. Yeah it's boring but I grew up on a farm. My dad used to have me stand in front of open gates and keep the pigs in just so he wouldn't have to close the gate and reopen it when he wanted to get out with the tractor. I did that for hours. In winter. I think I'll survive my office.

I also hate when people just link other things on blogs. 'Hey look at this cool kegerator robot!' Ok. That's good. But most of the EE/hacking blogs I read linked to that site on that particular day. It was a little excessive to read about it five different times, and I think we'd live in a worse world if I made it six. Just a link, no commentary, no analysis, no further ideas. Just aggregation. Go blagosphere. If anyone is actually reading this be assured I will NOT do that to you. If you, for some reason, subscribe to this blog you will not get that sort of 'content' (second meaning of the title!). You will get something original even if it's just meaningless ranting like right now (which, honestly probably isn't that original. Read Ecclesiastes).

And posting about how you have no time to post? No. Just Say No. Let me say one thing: it is essential to actively maintain something you want to build a following around. If you want people to read it then update it every day even if it's not particularly useful information or even tangentially related to your subject. People will either read it for the sake of reading or stop reading it altogether. But the people who read it for the sake of reading it will continue, daily, religiously. Then you can put ads in front of their face and get a shiny nickel. But it has to be NEW or at least something they don't ALREADY KNOW. If you dont' update your blog for a while then guess what? People know that. They can see it. So if you update and say 'I haven't updated for a while' they will respond 'We know' and leave. People aren't interested in things they already know. Better to update less often and with actual information than to tell people something they already know.

So that's my rant. Can you expect high-quality updates from me from now on? Probably not. I would actually have to do interesting things, or in fact, things at all. I'd have to have something to write about and it turns out I only rarely have that. And, if I start writing about non-engineering things I risk becoming like everyone else. And I HATE everyone else. They make me angry, hence the name of the blog.