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  • EEVblog #8 Part 1 of 2 – Graphical LCD display development

    Posted on May 10th, 2009 EEVblog 8 comments

    Graphical LCD display development and PIC demo board stories.


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    • Daniel

      In school we had to learn assembly, with which we used EVBplus.com Dragon HC12 (motorola). The class and instructor were a total joke. I taught myself more about Micros in the first 2 class sessions from reading the book then the instructor knew period. To be honest, knowing more then the professor does not imply I understood the hardware very well at all about the development board. I learned my assembly and it was a good experience in that regard, but relying on development boards can ussually be akin to shooting yourself in the foot, the only guy who should be confident using one is the guy who designed it!

      I have since turned into a little PIC uC guru, and theday I bought a Myke Predko book (amazon) ive been building up Controller circuits and really understanding the hardware. Unless the development board is more like a Pin/Crystal/Power breakout board, it is seldom worth the effort to figure out all the extra extraneous hardware that they have included that you will not need nor want.

    • ewertz

      Wow, I can’t believe that you’re complaining about not having every pin function silkscreened on the board. There’s practically not a microcontroller *pin* these days that doesn’t share functions unless it’s power or ground! I hope that I don’t have to break the bad news to you about having to set control registers to get any of those pins working, too…

      Please tell me you aren’t losing sleep over not having color bands on your SMT resistors too…

      I just think it’s kind of a cheap shot. It’s a circuit board, not a 500-page datasheet, mate!

      all the best (seriously!),
      -e

    • http://www.alternatezone.com/eevblog admin

      You’ve missed the point about the pin labeling. It’s not about the micro pin itself, it’s about what other stuff they hang off that pin on the demo board, it doesn’t just go direct to the I/O header connector. I had to *desolder* parts to get my board to work on the User I/O header. You don’t find out that stuff until you look at the schematic as I mentioned.

      It’s not a cheap shot, I’m just mentioning something that can catch people out.

      Dave.

    • Kyle

      Hey Dave!
      I’m going to be a freshmen in college within a couple of months and I have recently begun to become really quite interested in electrical engineering. This development wasn’t just out of the blue–I’m a avid programmer inside of high school and out. I have watched pretty much all of your video blogs and they fascinate me. One big problem is, I just don’t know much about electronics. I think it would be a neat idea if you dedicated part of your video blog to teaching the basics. You know, what each of the basic parts do(resistors, capacitors, transistors, relays, diodes, etc.), why those parts are useful or why they are needed, and then maybe get into a little more advance stuff like gates, timers, amplifiers and servos. I know I and a lot of other beginners would LOVE something like this. That would certainly provide you with an ample amount of material for future shows, not to mention new viewers as well!

      Thanks a ton doing what you do!
      –Kyle

      P.S. Do you happen to own an Arduino? I bought one recently and they are really nice!

    • http://www.alternatezone.com/eevblog admin

      Hi Kyle
      I might eventually move into beginner tutorial type stuff. I’m just trying to flesh out what my actual audience mostly consists of at the moment, so trying to keep it fairly generic at the moment.

      I haven’t used the Arduino as all of my designs are fully custom, but I know it is getting massively popular for those who just want a controller board without the fuss of designing your own.

      Dave.

    • ewertz

      Dave,
      Thanks for the clarification about your labeling complaint. I’ll have to admit that when I got my first dev/eval board, it was a learning experience trying to figure out what you could do with the board as delivered, and what you couldn’t, at least not without modifying the board.
      But after I thought about it for a moment, it made perfectly good sense. By adding anything to the board other than just a socketed processor and power supply, you start constraining what the board can do as delivered. Example — an LED to demonstrate that you’ve changed a digital output (always Lesson 1 in the User’s manual). By putting the LED on the board you’ve taken that pin out of play for some other use (for a full-voltage output, or as an input), unless you cut the trace or have a way to jumper-out the LED.
      So, it’s a design trade-off. Some boards present fewer of these points of contention that you pointed out, but they almost always deliver less out-of-the-box functionality.
      I think these are the types of design decisions that cause there to be three classes of pre-loaded microcontroller boards for learning purposes — demo, evaluation and development boards. The differentiating qualities being how much is hard-coded into the board for out-of-the-gate ease of use, versus flexibility for more advanced customization.
      When I see “demo” (and sometimes “evaluation”) board on a product description, I don’t expect to be able to do much more with it than press a few buttons, have LED’s light and get a few beeps, just to show the basics, and perhaps to be able to take a few measurements from it (like current consumption, etc). I don’t automatically expect to be able to use it as the basis of my own development or prototype. “Development” (and often “evaluation”) board pretty much means that while I can use it for most of my own evil purposes, it’s going to take some care and feeding to get it to do even some basic stuff.
      Point being that for every extra “peripheral component” that’s added to the board, the complexity starts increasing pretty quickly and a visit to either the manual or schematic is a necessity.
      Kyle happened to mention a great example of a pretty minimalistic board, the Arduino. One or two LEDs hardwired to two of the digital IOs, but nothing else but rows of headers. No confusion there about what a header/pin is for — no built-in features, no conflict. Easy peasy. At the other end of the spectrum are many of the Microchip boards, more like the one you mentioned. They’re can be great because you don’t have bring your whole component box to get that first switch, LED, pot or piezo dancing, but you’ll start bumping up against their design choices once you start doing your own thing with it.
      One thing that I’ve learned and that you’ve pointed out, I never ever buy or start playing with a board until I’ve looked at the schematic (which is often faster than plowing through a bunch of configuration tables in the manual). If the board’s got something other than a processor, a 2.x mm power plug and 7805 on it, the schematic’s my new super-best friend.

      -e

      PS: I really like the equipment reviews, especially the more detailed ones that you’ve been tending towards in the later shows. Personally, I’m a big fan of your dealing with more of the hands-on *non*-beginner material. There’s so much starter material out there (books, websites, etc.) that focusing on more lab-oriented, or advanced, stuff would continue to be a great, unique contribution.

      Keep up the great work. I assure you it’s appreciated.

      PPS: I’d also like to see more koalas on the show.

    • Cheng-Chih Kuo

      Hi Mr.Jones,

      Thanks again, for the lesson of Graphical LCD display development.

      BR,
      Cheng-Chih

    • Dan

      Hi Dave, I’m in college, am a E.E. student, and am taking a class in Embedded Control. We have gone over serial communication and your reference to parallel communication baffles me. I have no idea what it is or does. Also, in layman’s terms, how does one go about creating their own driver? Thanks.