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Everything posted by enl

  1. Use long int (or long unsigned) and use `ld' (lowercase ell d )instead of `d' in the format string for sprintf. `d' is standart int. `ld' is long int. The only info sprintf has about the type is from the format string, so if you spec standard int, whatever the param is, even if it is a long, will be interpreted as a standard int.
  2. What pin are you using for the PWM output? Is the timer you are using configured to modulate that pin? Also, what OUTMOD do you want? The sample used 3 (for S-R behaviour) Do you want 7?
  3. Any pin you want to use that is not already in use will work if you don't use interrupts. If you do use interrupts, then the pin must support that, which should include the unused P1 pins. If you don't need the start-stop function, you could re purpose the existing buttons for increase forward/decrease reverse and increase reverse/decrease forward. If you need to keep the existing function, add two more. In and case, with the run forward and run reverse as it is, I would put in code to protect from changing direction while the motor is running, including a delay to insure that the motor i
  4. @mfpek: Could you please give a bit more detail? What do ou mean 'control it with buttons'? With a microcontroller? If so, MSP430 or a different one? No microcontroller? I don't think anyone can really provide an answer without more information. Is this for a school assignment? (if so, it is good practice tosay so and to tell us what school/course/level) Also, is English not your primary language? Again, that is something worth mentioning before you get the 'sounds like homework, ask your teacher' response.
  5. I can address #4:the 39ohm R and 0.01uF cap form a snubber and are needed to prevent damage to the triac. They do not pass enough current to worry about in mot cases, but very small loads may have an issue, similar to when a CFL is controlled by a lighted switch, and the bleedthrough causes it to flash on every few seconds when the switch is off. On item 1: many components have electrically hot heatsink connections in some circumstances-- for example the heatsink tab for most BJT devices is connected to the collector, and on a linear amp may be 100V or more to ground, and not isolated e
  6. Just finished watching WKRP turkey drop episode. Happy Thanksgiving
  7. Pusle width of pulses in pulse train? That doesn't sound analog to me, either. So, in the interest of getting a meaningful answer, please clarify what the input signal is and what you want to know about it. Is it analog? Digital? Do you want frequency? Pulse width of individul pulses? Period of the periodic signal? Addressing a couple options: I believe Pulsein() will get the width of a digital pulse (I think it is the '1' state time), and is the appropriate tool if that is what you want. This would be appropriate when you are decoding a PWM signal. You can also measure the p
  8. More info needed to address this... What rate are you looking for? What are you using as ADC clock? What other modules are in use (do you have a free timer, for example)? Do you really need periodic sampling, or will demand sampling do?
  9. Well, simple, but not very useful, answer is fastest conversion the unit can do is a bit over 2uSec, for a bit fewer than 500000 conversions per sec, giving a max frequency that can be properly sampled of about 250Khz (Nyquist limit). This is presuming that max allowable ADC clock rate of 6.3MHz and a way to store samples at this rate. If you are using the internal ADC clock, the clock is not a precision device, allowing for significant variation with power supply voltage, temp, and manufacturing. This means we should really look at the max that is guarenteed achievable, which would be
  10. And low enough power to fit the suit...
  11. enl

    halloween 2014

    Nice. Simple and effective.
  12. You enable P1 interrupts for bit2. Do you have an interrupt handler for this? I do not see one in your code.
  13. This thread is now required reading for my intro programming students. And now I also understand (or at least think I do) more about how Python strings work, as well as the character and string encodings in modern practice.
  14. Not really new policy. It has come and go several times in the last few years. About a year ago, I requested samples and used my yahoo account for convinience, and it was rejected. hat is the same account I have used for years, and is registered with TI and National, but..... Resubmit with work email, no problem.
  15. I have used the G series UART at higher baud rates with no problem. Since you are not communicating to the PC via USB bridge, REMOVE the jumpers. Next, to talk MIDI, you will need whatever level shift and isolation hardware are required (I don't recall the details. I has been a long time). If you have a scope, you should be able to monitor the com that way. You can also loop-back while monitoring to confirm that you are on the right track. I presume you are using the default energia system clock setup, so 31250 is well within the zone for a good divisor on the UART clock (16MHz nominal clock d
  16. I have not used the low temp molding plastics like polymorph, but have read good reviews and know a few people that love them, despite the price. I have, in the distant past, used castable resins-- epoxy, acrylic, and polyesther-- and not had issues. I have not used the low heat-softening materials. I am not sure I would want a 10yr old using a material that needs to be worked at 60C or higher (references I have seen say 80 to 90 is better.... see sparkfun site, for example), but it does depend on the 10yr old. I cooked my own dinner, soldered, cast lead, used a grinder, etc at about that
  17. Depending what you are doing with the UART, it may not matter if you can trim the DCO to match a crystal. You CAN change the UART timer to match, as long as the bit rate isn't high enough that you are running fewer than about 50 DCO clocks per bit (for approx 2% adjustment per UART timer step) and you can do better than that with the clock dithering feature as long as the UART rate is lower than about 8 DCO clocks.
  18. Servos have the circuitry internally. No spark issues unless you are in a flamable atmosphere. generally no elecrronic noise issues, either. Typically, you want a separate (5 to 6 volt) supply for the servos due to the high current draw, as well as the issue with 3.3V controllers that most servos need at least 4.5V to operate reliably at all. Little noise is fed back via the control (PWM) input, and I have never had a problem. Most, but not all, are fine with a 3V control input, even with 5V power. Do check that your choice of servo isn't pulling the PWM input high to its power supply volt
  19. enl

    A buffer?

    buffers are used for protection even by the pro's to protect the expensive parts. Key words are: the expensive parts. Expensive in direct cost, or in down time and repair. If you are using the Gseries LP, the buffer costs almost as much as the microcontroller (between the IC, board space, etc), and limits you to only digital I/O, as well as requiring extra work to set up the buffer for input or output as needed, which costs time, complexity, and probably I/O pins. With most microcontrollers, most or all pins serve more than one potential purpose, such as digital I/O, A/D input, PWM
  20. not yet there other than special uses. Pricey, high resistance, not environmentally tolerant enough
  21. Depends what is connected to it. If it is a LP, I have no idea how you burned one out short of a direct short circuit to the USB port lines. I have used at least one LP as a fuse, due to screwing up power supply grounding (no isolation transformer when I needed one) but otherwise.... One thing that can help in the case of ground loops or power-to-ground faulting, which can happen with external power supplies, is to either use a laptop with on batterie, or, better, have the computer and the supply for whatever else you are using both on DIFFERENT ground fault interrupters, so that a fault w
  22. Working doing welding instruction in bordentown saturday. Won't make it. Have a couple friends and former students with booths so am bummed. Same problem (but different place) last year.
  23. @abc: Short answer on steppers: They take high current Long answer: Because stepper motors can provide significant torque at moderate to high speed, they need a higher power than the output pins of most microcontrollers can provide. This equates to higher current. The simplest interface, for small, low power steppers, is a single bipolar junction transistor, like a 2n3904, with a resistor and diode for current limit and inductive kickback protection. It is actually cheaper and easier to use an IC designed for the purpose, with all of the needed features built in, such as the ULN2003, with
  24. Power consumption is roughly proportional to clock speed when active. The 32KHz crystal takes less than 1uA (see LPM3 power with LFXT1 Aclock, p23 in SLAS735J MSP430G2X53) itself, so the principal active power will be based on what you are doing, clock speed, and supply voltage. Whether you use the 32KHz clock as Mclock or use the DCO, or use..... doesn't make a lot of difference to the average power, if the device sleeps in LPM3 when not doing something. Average power will be about the same. The DCO and internal oscillator take a little power, but still quite low. If ou need speed when ac
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