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dannyboy

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  1. Like
    dannyboy reacted to VMM in Another 430 Watch   
    Hello.  I figured I would share a project I've been working on since I borrowed a lot of code from this forum.  It's a small watch using a g2553 and the same OLED display as "The Terminal".  Thanks bluehash for the breakout, RobG and gwdeveloper for code, and others.  

  2. Like
    dannyboy reacted to veryalive in MOSFET failures I can't explain   
    i do understand your desire to do the job by yourself      = >  persistance.
     
    - sounds like your wiring is ok, but the mosfets need higher drive voltage than the 430 output provides
     
    - if you have bipolar transistors available, you can drive their base via a resistor (1 to 2 K ohm) from the 430, ground the emitters, LEDs to the collectors.  they only need about one volt at the base to turn on the collector current.
    - in this case, a medium power NPN, darlington if you have them.   (there any many low cost options,  one is BD139)
     
    - sticking with bipolar, due to the lower turn-on voltage, think of the uln2003 driver family. 
    multiple drivers in one package for your stated 'compact size' requirement.
    you may have to invert the logic level in your IO pin-driving software.
    again, there's lots of similar drivers out there.
  3. Like
    dannyboy reacted to Mark Easley TI in Stellaris LaunchPad only $7.99 on eStore   
    https://estore.ti.com/Stellaris-LaunchPad.aspx
     
    TI is trying to move the Stellaris LaunchPads to make room for the new Tiva C LaunchPads.  Both boards are pin for pin compatible so if you want to pick up an ARM Cortex-M4F based LaunchPad for cheap, now is a good time. 
     
    Cheers!
  4. Like
    dannyboy reacted to oPossum in MOSFET failures I can't explain   
    The gate of the STP16NF06 should be driven with at least 8 volts. See figure 6 in the spec sheet.
     
    There aren't many MOSFETs that can be directly driven by the MSP430.
  5. Like
    dannyboy reacted to RobG in MOSFET failures I can't explain   
    Can you show your connections?
     
    Also, this might be helpful.
  6. Like
    dannyboy reacted to spirilis in MOSFET failures I can't explain   
    Might not have been giving enough voltage to the gate... Vgs(threshold) is ~2-4V, but that's at Vds=Vgs, Id=250uA ...
     
    What kind of voltage are you supplying to the LED strip, and about how much current do you expect to put through it?  Holding the gate active with a low voltage keeps the MOSFET in a "linear mode" where its resistance is higher, so it may dissipate more heat than it normally would if, say, you sent 9V into the gate using some sort of adapter hardware.
     
    In adafruit's example, they're using an Arduino which typically runs at 5V ... that might be good enough not to fry it.
     
    Could be something else though, just wanted to toss that out there as food for thought.
  7. Like
    dannyboy reacted to HanzZ in QSimKit - MSP430 simulator   
    Hi,
     
    as my diploma thesis I'm writting MSP430 simulator called QSimKit. It's not finished yet, but it's in state when it's starting to be useful and I would like to get more people to test it, share their opinions, find bugs and basically to create community of people interested in MSP430 simulation.
     
    Releases:
    Version 0.0.3 (2014-02-04), Changelog At first some facts about QSimKit:
    It's written under GPLv2+ in C++/Qt, has been tested on Linux or Windows together with msp430gcc. It supports peripherals (as plugins) written in C++ or Python. Currently there's LED, oscillator, button and HD44708 LCD (not fully implemented yet). MCUs are plugins too and theoretically it's possible to add support for more MCUs (not just MSP430). It can support all MSP430 variants, but only few are supported right now, because I haven't created package data for all MSP430 variants yet. In graphical user interface (Check screenshot), you can do following:
    Add peripherals, connect them to MCU. See the source code of program you are simulating together with Dwarf debugging data (you can see the value of local variables for example) and current instruction. Step the simulation, add breakpoints based on PC register or value of memory. Track pins in oscilloscope-like view. See the registers and other important values from MCU (frequency, BasicClock registers, ...) MSP430 MCU plugin can do following:
    Load ELF/A43 code. Supports all instructions. Supports BasicClock module (TImerA/TimerB). Support for USCI-SPI [NEW in 0.0.3] Support for USART-SPI [NEW in 0.0.3] Initial USI support (just SPI mode). Peripherals:
    Button LCD - HD44708 (only initial support) LED Crystal Oscillator SD Card (only initial support) [NEW in 0.0.2]  
    As I stated earlier, it's not finished yet, but some testers to help me testing are welcome. I can also help anyone who would like to help with development. There is no development documentation yet, but if you tell me what you would like to do, I can write relevant docs to help you.
     
    If you think you have found a bug or you have some feature request, please create ticket on GitHub, I don't want this forum thread to be an issue tracker. You can also find me on IRC in #qsimkit at freenode or as HanzZ in #43oh channel.
  8. Like
    dannyboy reacted to veryalive in 8-bit 2-to-1 multiplexer IC   
    if you wish to minimize hand wiring & are using veroboad or single sided pcb.....
    a pair of 'hc541.  one on the left, one on the right.
    BUT the one on the right is upside down; why? 
    so that you can do straight-through wiring on the output lines
        (so  left p18 to right p11.    left p17 to right p12.   ..etc..   left p11 to right p18)
     and then select via the output enables on pins 1 and 19.
     
             | o |
    8 inputs |   |   8 outputs   |   |
             |   |    3-state    |   |  8 inputs
                                 | o |
  9. Like
    dannyboy reacted to oPossum in 8-bit 2-to-1 multiplexer IC   
    A pair of 74HC244. Tie the outputs together, only enable one at a time.
  10. Like
    dannyboy reacted to oPossum in Curiosity Poll: forum member location   
  11. Like
    dannyboy reacted to leomar01 in Oscilloscope or logic analyser?   
    I'm relatively new to tinkering with electronics. Soon I felt like I would need an oscilloscope. I'm also still a student and thus, money is always a problem. My parents got me the above mentioned DS1052E from Rigol as a birthday gift (man I'm lucky). Not much time went by until I was sure I would also need a logic analyser. Of course I bought that very good Saleae Logic. Now (after 3 months) I can say that I should've bought the Logic first. I can check almost everything I need with the Logic. I really recommend you to buy the Logic first. Then, please do yourself that favour, save your money for a real o'scope like the DS1052E or better. Don't waste any more time on even thinking about something like the DPScope.
    I hope this helps
  12. Like
    dannyboy reacted to larsie in Oscilloscope or logic analyser?   
    I use the Open Workbench Logic Sniffer a lot, and the Bus Pirate a bit. They are quite cheap, but still very useful. The Open Workbench Logic Sniffer is at least very useful to me.
  13. Like
    dannyboy reacted to pabigot in Oscilloscope or logic analyser?   
    The logic analyzer. That Saleae has saved me many hours debugging UART, SPI, and I2C issues, confirming that even if the target chip isn't responding I've at least got the peripheral configured right. It allowed me to determine the pre-programmed RF2500T from TI didn't conform to the bundled source code, by snooping to show me how it actually configured the radio. It handles inter-event time measurement by triggering on GPIO changes, and let me confirm the cycle delay counter in mspgcc was accurate.
     
    Get a better multimeter with the change, if you're not happy with the one you've got.
     
    Based on other discussions here and my own experience with the DSO Quad, a cheap scope isn't worth the money. (The Quad's a neat little thing, and if the interface was sane and it came with understandable instructions it might not sit in a box for six months between uses.)
  14. Like
    dannyboy reacted to oPossum in Multiple frequency output using TimerA   
    This is the usual way the handle TAIV:
     

    switch(TAIV) { case 2: // TACCR1 // Handle CCR1 interrupt break; case 10: // TAIFG // Handle timer reset interrupt break; }
     
    Reading TAIV and ignoring the value is a hack.
     
    See page 367 of slau144 for details.
     
     
    Interrupt flags are typically only cleared explicitly when the flag is polled rather than using an ISR.
     
    Two independent time intervals without using ISRs would require two timer units.
  15. Like
    dannyboy reacted to oPossum in Multiple frequency output using TimerA   
    You have to read TAIV to clear the interrupt flag
     

    #pragma vector=TIMERA0_VECTOR __interrupt void TIMERA0(void) { P1OUT ^= BIT2; // Toggle green LED CCR0 += 60000; } #pragma vector=TIMERA1_VECTOR __interrupt void TIMERA1(void) { volatile unsigned z = TAIV; // Clear interrupt flag P1OUT ^= BIT3; // Toggle red LED CCR1 += 50000; }
  16. Like
    dannyboy reacted to HylianSavior in Standard file format for schematics?   
    I wouldn't say that there is one single format for a schematic, dannyboy. All editors have their own formats. Typically, if you wanted your schematic to be viewable by everyone, you'd export it to a pdf or the like, as bluehash mentioned.
     
    An interesting site you might want to look at for sharing schematics is CircuitBee (Google CircuitBee). It currently only accepts KiCad schematics, but they're working on other formats as well.
  17. Like
    dannyboy reacted to oPossum in 5v to 3v?   
    If the MSP430 and the I/O attached to it draw ~ 25 mA or less, then an ordinary red LED can be used to drop 5V to 3.3V.
     
    Video shows schematic, and explains this circuit.
     


     
    A pair of AA or AAA alkaline batteries is also a handy source of 3V power.
  18. Like
    dannyboy reacted to nuetron in Beginner hack: a speaker with amplifier   
    1. The LM358 should work just fine.
    2. I don't have much experience with op-amps, but I have done alot with comparators, which are the digital version of op-amps.
    3. No, you aren't, it should work.
    This is what I suggest you do:
  19. Like
    dannyboy reacted to timotet in LaunchPad: Watchdog timer interrupts and TACTL   
    hey look at this viewtopic.php?f=10&t=509
     
    and to let you know you dont even need to use the watchdog for this.
     
    the delay is the problem
    use this delay instead :
     
    static void delay(int ms)// Delays by the specified Milliseconds
    {
    while (ms--)
    __delay_cycles(1000); //set to 1000 for 1 Mhz
    }
     
    and take out the watch dog interrupt call all together.
    and be sure to put this in
    WDTCTL = WDTPW + WDTHOLD; // Stop watchdog timer
     
    TACTL is for TIMER A and has nothing to do with the watchdog.
    page 410 of the msp430 users guide will explain the TACTL register and what it does
     
    good luck
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