Jump to content

GeekDoc

Members
  • Content Count

    1,391
  • Joined

  • Last visited

  • Days Won

    13

Reputation Activity

  1. Like
    GeekDoc reacted to rockets4kids in Vetinari's Clock   
    Funny you should mention this -- a digital version of Vetinari's clock has been on my back burner for a while now.  ;-)
  2. Like
    GeekDoc reacted to abecedarian in Vetinari's Clock   
    I know this is oriented at an analog clock, but would it be any less disconcerting if applied to digital?
     
    I know I'd be left wondering if a set of LED's sat reading "09:14:48" for a bit then suddenly counted up to "09:15:30" only to pause for a bit then up to "09:16:00"... or even ran backwards for a bit.
  3. Like
    GeekDoc reacted to ChristianGeek in Reflow Oven Booster Pack   
    It's his design, and he mentions IP and trying to recoup his costs in one post and the schematics are clearly labeled as for learning and reference use only. Without his OK, I don't think this would be cool at all.
  4. Like
    GeekDoc reacted to RobG in Testing boards   
    The quest for the best test solution continues.
     
    POGO pins are great, but they require pressure and mounting takes time.
    Also, they are not the most reliable, noticed some internal contact issues.
     

     
     
    I went back to my older idea, using 0.1" edge connectors. 
    The problem with those was that I had to have enough room for the plastic part of the connector.
    Well, I have cut off the top portion and now I can test almost all of my boards.
     
    (It's a test test connector, so it's not pretty)

  5. Like
    GeekDoc reacted to enl in How to calc this resistor ?!   
    Detailed explanation:
     
    There are several types of power supply, but the type most often seen in the consumer and electronics world  is constant potential (constant voltage). The current specification is the MAXIMUM current it will supply at the specified voltage (give or take... sometimes the voltage will drop a bit before the current rating is reached, sometimes there is a little leeway), but the voltage is, nominally, fairly constant for most types.
     
    Most important is the type of supply...
     
    Presuming that the supply is a DC supply, three main types exist. Unregulated, linear regulated, and switching.
     
    Most wall wart types are unregulated or switching, thought there are a few linear regulated in the wild.
     
    Unregulated may provide much higher than rated potential at lower than rated load, and are generally not very stable, with a lot of noise (typically at 100 or 120 cycles per second, depending on line frequency, and up to 50% or more voltage at full load), and should not be used with devices requiring regulated supplies.
     
    Switching are pretty tightly regulated, and generally cut out (drop to near zero output) if the rated current is exceeded by more than a few percent. Within the rated current, they drop very little with load and have moderate to low noise -- maybe less than a percent -- at high frequency (10 KHz to 1MHz). Some types may not regulate with less than a few percent load, so ALWAYS load these at 10% or so current when testing them, and be careful when using to power low loads. For low loads -- less than about 10% rated -- check with a dummy load to be sure that it regulates. Use an oscilloscope, as the overvoltage may be pusles to pretty high potential, with average potential looking ok on a meter. This isn't as big a problem with modern supplies as with the units from the 70's through the 90's, but some of the no-name and counterfeit units from the far east are pretty bad.
     
    linear are typically the least noisy, but not as efficient as switching types. They may have a little more variation over load than switching, in the simpler ones, but can be significantly more stable than switching in the higher quality designs. They tend to drop off more gradually at overload, and usually are conservatively rated, tolerating a few to 20% overload, at least for a brief period, without dropping from specified voltage. They generally regulate well down to zero load, but some may have stability issues with loads that are principally inductive or capacitive. Then again, so can switchers.
     
    -----------------
     
    If the original supply was regulated, and the new one is (switching or linear), no issue.
     
    If the original was unregulated, or the new one is, then you need to do some work to be sure, but are likely ok. If the old one was, the new one should be fine as long as the device powered wasn't relying on the supply limiting current.
     
    If the new one is unregulated, DO NOT use it. You will likely have a problem.
     
    If old and new are both regulated, no dropping resistor needed and all should be good.
     
    ------------------------
     
    Additional info: many older (1970's and 1980's) supplies were unregulated and were designed to work with a particular load. The transformers in much consumer grade product used saturation limiting in the transformer for protection from overload (often no fuse or thermal protection was used... sat limiting met the requirements for certification by UL and other ratings agencies if the primary wire could safely burn on a primary short... still find devices like this even today) The saturation limiting also provided a controlled drop under load, and a nominal 5V supply might show 8 or 9V open circuit, dropping fairly linearly to 5V at rated load, and limiting current at not much more due to transformer saturation. These types of unit ARE NOT suitable for modern electronices, are not that safe, and should not be used with anything other than the devices they were designed for. Back in the 90's a ton of Coleco and other similar wall warts came on the surplus market that fall into this category, as well as a bunch of cord-and-brick supplies. Lost a lot of gear to unclueful power suppply replacement. Mostly other people doing it, as after the first time, I learned (but still managed to lose a really nice frequency counter to my not looking at the supply. Right connector, so I went with it. Poof!)
     
    More info, since I have diherria of the typing finger (and it is frigid and windy here):
     
    The other type of supply is constant current. They tend to be seen as blocks in circuits (op amps use them by the bucketful internally), but are sometimes seen in high power applications. There are parts of the world (eastern europe and rural US, in particular) where costant current street lighting is still used. The lamps then don't need individual ballasts, but must fail electrode shorted at end of life.
     
    Yet more info: MIG and fluxcore (wire feed) welding is constant potential. Stick (SMAW/MMA) and TIG (GTAW) welding are constant current. Neither is true constant, and true constant potential or constant current makes for a very difficult to control process. Real welding sources have some 'droop', to allow for an equilibrium to be established with inherent negative feedback for control. This holds true for both manual and automated processes, though automated processes are often held to a flatter curve.
     
    ----------------
     
    Cat got off my lap, so I'll stop now....
  6. Like
    GeekDoc reacted to spirilis in Noritake Graphic VFD 128x32 Free Sample   
    Thanks for reminding me to get mine out & play with it :grin:
     
    Just got mine working on the F5529 LaunchPad.  I'm using C with my own cooked up libraries for setting the clock and doing UART I/O, but Energia will probably work a heck of a lot easier for this.
     
    Serial I/O is 115200 (J0 & J1 are shorted on the back with solder blobs; see datasheet PDF page 29)
     
    Product page for these series of displays: http://www.noritake-elec.com/7000.htm
    Command cheat sheet: http://www.noritake-elec.com/7000commands.htm
    Datasheet: http://itron.tv/gu140x32f-7000-d
     
    Hello world:

     
    Pinout:

     
    Pins are showing top-to-bottom which I think is reverse order but they are:
     
    RESET
    N/C
    SBUSY
    GND
    SIN
    VCC
     
    RESET is an input, I hooked mine to P6.0 and it's RESET=LOW, ENABLED=HIGH (similar to the reset behavior of the MSP430).  I just set P6.0 low for a short delay and high before sending the serial INIT command.
    SBUSY is a GPIO output driven by the VFD telling you when the display is busy doing things and you shouldn't send it data... I am assuming this is a 5V level I/O so I didn't hook it up anywhere and used __delay_cycles() with reasonable delays.  Might make a small adapter board with a level shifter for that.
    SIN is the serial input, I hooked it up to P3.3 (UCA0TXD) and did all my I/O using USCI_A0 (UCA0TXBUF et al).
    VCC goes to 5V, GND to GND.
     
    This program uses two libraries of mine (one of which I doctored up for the F5529 with USCI_A0) which I may polish and post later-
    #include <msp430.h> #include <stdlib.h> #include <string.h> #include "clockinit.h" #include "uartcli.h" char inbuf[8]; extern void uartcli_tx_lpm0(void); int main() { WDTCTL = WDTPW | WDTHOLD; P4DIR |= BIT7; P4OUT |= BIT7; P4SEL &= ~BIT7; ucs_clockinit(16000000, 1, 0); __delay_cycles(800000); P4OUT &= ~BIT7; uartcli_begin(inbuf, 8); // Noritake RESET line P6SEL &= ~BIT0; P6DIR |= BIT0; P6OUT &= ~BIT0; __delay_cycles(160000); P6OUT |= BIT0; __delay_cycles(160000); UCA0TXBUF = 0x1B; uartcli_tx_lpm0(); UCA0TXBUF = 0x40; uartcli_tx_lpm0(); // INIT __delay_cycles(160000); UCA0TXBUF = 0x1B; uartcli_tx_lpm0(); UCA0TXBUF = 0x52; uartcli_tx_lpm0(); UCA0TXBUF = 0x00; uartcli_tx_lpm0(); // set font 0 (US) __delay_cycles(160000); uartcli_println_str("Hello world!"); LPM4; return 0; } Apparently there's all kinds of commands to send starting with 0x1B, see the command cheat sheet.
    Looks like a cool display!  Gets warm to the touch after a few minutes though.  Not a low-power gadget.
  7. Like
    GeekDoc reacted to dubnet in 43oh Welcomes Saleae, Exclusive 43oh Member Offer. Ends Nov. 13, 2013   
    I went back and forth for about a week on this. Ended up going for it. It should be here Friday.
     
    Thanks to bluehash for making these kinds of things happen and to Saleae for their support of the 43oh community.
  8. Like
    GeekDoc reacted to toddbranch in US Air Force Academy Embedded (Launchpad) Class ECE382 for free   
    Thanks for the positive feedback!  
     
    We're going to transition the course to a new learning board for next year.  The current plan is to use the educational boosterpack (http://www.boosterpackdepot.com/), but I'd love to get your feedback if you think there's something better out there.  All we really need is an LCD and some push buttons.
     
    If you have comments / criticisms about any part of the course, I'd love to hear them and have the community help drive the direction of the class.
  9. Like
    GeekDoc reacted to zeke in US Air Force Academy Embedded (Launchpad) Class ECE382 for free   
    @toddbranch:  
     
    If you need a better board (or peripheral boards) for your classes then why not ask the crew here design it (them) for you?
  10. Like
    GeekDoc reacted to chicken in 3D Printer to print circuits - Cartesian EX1   
    Interesting. Not sure what's 3D about it though, looks pretty 2D to me.. I guess it helps the buzz :roll:
  11. Like
    GeekDoc reacted to jpnorair in LEDs blink/fade with music?   
    The only way out of newb-ness is to do a project.  
  12. Like
    GeekDoc reacted to marfis in WS2812 demo with MSP430 5529 launchpad   
    Hi,
     
    here is a small project that runs on the MSP4305529 launchpad:
    https://github.com/hoihu/WS2812
     
    that supports the 800kHz WS2812 LED strips (e.g. http://www.adafruit.com/products/1138 and others) by using the DMA controller rather than a while loop.
     
    The idea is based on the SPI approach by RobG:
    http://forum.43oh.com/topic/3971-wearable-ws2812-strip-controllers/
     
    + work is delegated to DMA, frees foreground application (easier to code color changes etc) - needs app. 8x more RAM, as the LED bits must be deflated in advance in memory   The main loop shows a nice looking color fading effect: IMG_1090.MOV   any comments/extensions are appreciated.
  13. Like
    GeekDoc reacted to abecedarian in LEDs blink/fade with music?   
    @@CodilX - Don't give up.
     
    Look at some of the projects others have done and try to determine what elements of others' projects could help you achieve your goals. And ask questions.
    It's not likely someone will do all of the work for your, but many here will help guide you. Some might be so kind as to design 'basic' circuits to help you.
     
    Good luck on your travels. ;-)
  14. Like
    GeekDoc reacted to bluehash in 43oh Welcomes RobotShop.Com! Exclusive 43oh Member Offer. Ends Dec. 31, 2013   
    We are excited to welcome RobotShop.com as a Sponsor to 43oh. They have alot of bits and pieces as well as full robot kits. Alot of things that can come handy for your MSP430 POTM project.

     

    43oh members get an exclusive offer with RobotShop.com: a 7% discount on their order. It will be valid till Dec 31, 2013.  Code: 43oh

     

    Thank you!

  15. Like
    GeekDoc reacted to legailutin in Nov-Dec 2013 Project of the Month Sponsors/Planning   
    Can I add my modest contribution? I would like to add three (3) Li-Ion 3.7v 1150mAh batteries to the prize pool.
     
     
    Will Post the pictures as soon as I get home tonight. I have used it in a project using schematics and parts of the LiPo boosterpack. It charges and works perfectly. I can share the Kicad schematics with the community when needed.
     
     
    A picture of all three batteries.

  16. Like
    GeekDoc reacted to chibiace in Interesting Project to port to the MSP430 - ATtiny45 project adds sound activation to PC   
    computers can be turned OFF???!
     
    why not go directly into the soft power switch of the computer? then you can shutdown too.
  17. Like
    GeekDoc reacted to bluehash in [ ENDED ] Oct 2013 - 43oh Halloween Contest   
    Animated Darth Vader Build Monitor[Fred] (2 votes [18.18%])
    MPY Halloween Ghost Project[MPYMike] (5 votes [45.45%])
    Glowing Pumpkin[t0mpr1c3] (0 votes [0.00%])
    Halloween Eyes[enl] (4 votes [36.36%])
     
    Thank you all! @@mpymike wins this years Halloween Contest. @@Fred, @@t0mpr1c3 and @@enl, please PM me your addresses. I'll be sending out a Protoboard a blank v1.4 Launchpad. Congratulations to all. Thanks for participating!
     
    MPYMike, PM me your address too. You have the BT kit.
  18. Like
    GeekDoc reacted to cubeberg in 3D printed bumper.   
    Remixed it a bit - added mounting holes (for a robot project I'm working on)
     
    https://tinkercad.com/things/0j3oCI4ttHQ
    http://www.thingiverse.com/thing:168796/#files

  19. Like
    GeekDoc reacted to PentiumPC in 3D printed bumper.   
    http://www.thingiverse.com/thing:92339
     
    Just to share a simple bumper I made for MSP430 Launchpad.
     


  20. Like
    GeekDoc reacted to luke in First actual fried MSP430   
    Not sure how prevalent, sane or amorale this is but back in 1979 (not a typo) being a young software engineer (no EE at all) I was tasked with writing code to control some things for Chicago Transit Authority. The custom board was in early stages of development and had some shorts. The gave a scope, a meter and sail go find the shorts. After a day or two we all agreed it was not going to happen soon on this complex board and we were under a very tight time line. Since it was an early stage board we decided to use the "hydro test" (this was Ontario). We simply plugged it in the 120v and looked for the fireworks, I learned a lesson, sometimes brute force is the best solution.
  21. Like
    GeekDoc reacted to ILAMtitan in First actual fried MSP430   
    You got off easy.  I do a lot of work with mains voltage, and learned my lesson about debugging without an isolated interface early on.  THis one blew out my laptop's dock as well in the process.
     

  22. Like
    GeekDoc reacted to roadrunner84 in Is BoosterPack-like solution lame in my case?   
    I think boosters are nice for hobbyists, it is very low threshold to just buy a cheap board, plug it on your existing dev platform and try things.
    When building a product (whether it's for mass production or small scale amateur applications) I think a custom board with an MSP on it is much more interesting. For one thing because you're not stuck with the formfactor. You can get rid of the programmer/emulator part which you won't need in a product.
    In the case of a QFP package it's a bit harder, but for the DIP solutions (like the MSP430G2 launchpad) it's much easier (and probably cheaper) to either pus a chip socket on the board or supply a small in-circuit programming connector (the eZ430 connector), than it is to route all pins for the booster pack interface.
  23. Like
    GeekDoc reacted to bluehash in Interesting Project to port to the MSP430 - ATtiny45 project adds sound activation to PC   
    ... by emulating a HID mouse or PS2 interface on a LP or standalone MSP430.
     
    http://dangerousprototypes.com/2013/11/03/attiny45-project-adds-sound-activation-to-pc/
  24. Like
    GeekDoc reacted to bluehash in 43oh Welcomes Saleae, Exclusive 43oh Member Offer. Ends Nov. 13, 2013   
    We are excited to welcome Saleae as a Sponsor to 43oh. Saleae makes USB-based logic analyzers which can record over 1 billion samples and decode SPI, I2C, Serial, 1-Wire, CAN, Manchester and I2S. They are known for their Logic 8 and Logic 16 Analyzer and very intuitive user interface.

    We have met them at a couple of Maker Faires and are a fun bunch of people.

     

    43oh members get an exclusive offer with Saleae : a 20% discount on their order. It will be valid for the next two weeks (until November 13th).  When the code is entered, it will display "43oh.com" in the checkmark box (see picture below which currently says "Educational Discount").  Code: SWGRB5HJ

     

    If you are ordering a Logic 8 Analyzer, drop them a thank you note for sponsoring our community.


  25. Like
    GeekDoc reacted to dukevimto in A Strangely Familiar Pumpkin   
    Halloween comes round, and I can't face all that orange goo everywhere.... so I went cardboard.
    Rectangular things are easer. What about doing  a cube?

     
    Oh, yes!
     
    And, of course, it needs some good lights:
     

     
    The 5mm round LEDs are RGB, the larger ones are high-brightness white. These are driven with a high pulse current to create the impression of lightning.
     
    Code is here:
     
    Video:



×
×
  • Create New...