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  1. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    I see that you are now using the 10F320. The post you were replying to was the workaround for using the 10F200. On the 10F320 sleep does indeed work they way you wanted it to. Bob
  2. BobK

    Microcontroller and Stepper motor.

    Current sensing resistors are really no different than ordinary resistors except that they come in very low resistances and high precision and high power. For your application, I would just get a 1% or better resistor of the value you need. For 0.275Ω and 2.4A the power is 2.4^2 * 0.275 =...
  3. BobK

    Looking for a task management system that uses fobs...

    It took me almost 1 minute to find this: http://www.guard1.com/Solutions/How-a-Guard-Tour-System-Works.aspx Bob
  4. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    Adam, You can check the ~TO bit in the STATUS register to tell the difference between power up and wake up from sleep on WDT timeout. Bob
  5. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    Adam, That is how sleep works on the baseline PICs, which the 10F200 is. It resets the PIC on wakeup. That is one reason why I recommended the 10F320 instead, it is an enhanced midrange PIC and will wake up after the sleep instruction. Bob
  6. BobK

    Help with time counter for wildlife research

    Yes, you can drive an LED, up to 20mA directly from a PIC pin. I would switch to the PIC10F322. It is only a few cents more, has the same pinout and more memory and capabilities, and is easier to program. Edit: The bypass cap is correct and should go as close as possible to the power...
  7. BobK

    flux / soldering paste..

    I have this bargain priced soldering station and I am very happy with it for both SMT and through hole work. http://www.ebay.com/itm/2in1-898D-Soldering-Rework-Station-Hot-Air-Gun-Solder-Iron-Welder-ESD-W-Nozzles-/311097028454?pt=LH_DefaultDomain_0&hash=item486ed3ef66 By the way, can anyone...
  8. BobK

    Help getting started on new project

    Yep, sounds like another one who wants to build his own wrist band that does more than a fitbit and they can build it themselves for less money. Not going to happen. Bob
  9. BobK

    Building an Audio Amplifier

    Like Dave said, the transistors you are using will not produce 1W, let alone 5W. You would need power darlingtons to output that much power. Bob
  10. BobK

    regulate fan speed

    A potentiometer will not regulate its speed. You need feedback to regulate its speed. How many wires does the fan have? Bob
  11. BobK

    Making waves into DC

    Actually I would like to take back my comment about negative energy. Since energy is the ability to do work, I have encountered negative energy (the ability to undo work) in a couple of people who I have worked with. Bob
  12. BobK

    Making waves into DC

    OK, in other words, the 5.8V is the battery voltage. So the amp is there only to determine if you are producing power from the antenna. Why not use an LED? If you find any negative energy, I will nominate you for the Nobel prize. Antennas are not powered, and they do not attract waves. They...
  13. BobK

    I can't see how this will work

    If I understand what you are measuring, it is not across the LED it is across the resistor. i.e. the two probes are connected to either side of the resistor. Connect them to the two sides of the LED instead and see what you come up with. Bob
  14. BobK

    How I can configure an AVR microcontroller PWM to find the set point using a servo (DC ) motor?

    Are you trying to control the position of a motor without feedback? If so, it is not going to work. To turn a DC motor into a servo, you have to mechanically drive a potentiometer that will be read by the micro to determine the position. Bob
  15. BobK

    flux / soldering paste..

    Well, those are two very different soldering tasks. Paste is normally used for soldering SMT components with a reflow oven, though it can be used with a soldering iron as well. Most other soldering in electronics can be done using rosin core solder, which has the flux inside. Bob
  16. BobK

    Making waves into DC

    I think your circuit makes no sense at all. What are you trying to do. Where do you measure this 5.8V? Bob
  17. BobK

    PIC16F870 frequency counter

    The problem with counting pulses for 1 second is that the accuracy will be very low at the low end of the range. What if you get 1 count? It could be anywhere from 2 RPM to nearly 0. So the error can be as high as 100% of the value you read. At 10 ticks it is still 10%. For these low...
  18. BobK

    PIC16F870 frequency counter

    Hop, I knew you could get that answer, I was hoping the OP would try. And he did get counting cycles between pulses. metiz: So you have the answer. You can count pulses in a time interval or count time between pulses. The chip has timers. Read up about them in the datasheet and see if you...
  19. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    The micro has a watchdog timer that you can run while in sleep and it will wake the PIC up when it expires. You can set the time to expire over a fairly wide range. I assume that is what Adam is using. Bob
  20. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    The capacitor value should be way above what is needed if the uController is sleeping during this time. The sleep current is < 1uA and 1 1uF capacitor will lose 1 volt per second at that rate. Bob
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