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  1. KrisBlueNZ

    Digital clock using DS3234

    The DS3234 is a real-time clock with a serial interface (SPI). To read the time information, you really need a microcontroller. The microcontroller would also have to convert that time into digits to be displayed, and provide a way to set the time, and implement any other features you want...
  2. KrisBlueNZ

    low voltage comparison/amplification

    I'm not sure what you're asking. If you connect a reference voltage to one input, but leave the other input floating, the output state is undefined. It could be high or low or somewhere in between, and it could oscillate. You need to connect both inputs to something. If the non-inverting ("+")...
  3. KrisBlueNZ

    low voltage comparison/amplification

    LM324 is a quad op-amp. It can be used as a comparator though. LM339 is a quad comparator.
  4. KrisBlueNZ

    Ring Modulator (dalek emulator)

    FWIW I think the distinctive Cylon voice sound is done using ring modulation with a carrier frequency in the audio band. I guess if you use a lower carrier frequency you get a Dalek voice.
  5. KrisBlueNZ

    Hybrid Electric Engine

    I was going to point out exactly the issues that duke37 pointed out in post #2. I very much doubt that an engine using that scheme would be practical, cost-effective, or reliable. It's an interesting idea, but I think that car manufacturers would have considered ideas like this, and many...
  6. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    Yes, that's very applicable to this kind of project, when you're really working out how to do things as you go along, because the requirements are pretty complicated but they're also flexible, and the order in which you add features during development (as well as whether any given feature is...
  7. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    I guess the fundamentals are the same as programming a computer. The obvious differences that come to mind are resources (much less memory, slower processor), no operating system (although RTOS, real-time operating systems, are available) and the built-in peripherals, which you need to access...
  8. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    I agree it could have been explained a lot more clearly. The processor can only do one thing at a time. (Assuming it's a single-core device!) A while() loop operates like this: First, the condition (between the parentheses in the while() statement) is tested. If it's false at that time, the...
  9. KrisBlueNZ

    LM393 comparator...

    Those specifications are for VCC = 5V. Sorry, I should have pointed that out. The data sheet claims it can operate down to 2V but clearly its performance will suffer. My guess is that the current source for the base of the output transistor doesn't work properly at 3.3V. To the OP: I wouldn't...
  10. KrisBlueNZ

    LM393 comparator...

    The LM393's outputs are designed to pull "fairly low". Often they're used with digital logic, where low is anything between 0V and 0.8V, often more. There will be some variation from one manufacturer to another. I'm working from the data sheet from Texas Instruments for the device that was...
  11. KrisBlueNZ

    Ring Modulator (dalek emulator)

    AFAIK the ring modulator sound is more closely associated with the voices of the Cylons from Battlestar Gallactica. The Dalek voices may use ring modulation as well, but I'm pretty sure their main characteristic is amplitude modulation with a sinewave at somewhere around 15 Hz.
  12. KrisBlueNZ

    Current Direction

    Yes, it needs a complete circuit, but "ground" is the irrelevant part, as Dave says. "Ground" and "Earth" really mean the soil of this planet, or the Earth pin of an AC mains outlet, which is (supposed to be) connected to the soil via an earth stake. The words "Ground" and "Earth" are also used...
  13. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    Yeah, what Steve said :-)
  14. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    That's right. When the processor gets to a while() loop, it just executes the contents of the loop repeatedly until the while() condition becomes false, then it proceeds to the next part of the program. When you wrote while (row == 0) { random code to be executed-row0; if (timer == Y)...
  15. KrisBlueNZ

    No voltage drop

    Your fault description sounds like you may be applying the input voltage to the DC-DC converter with the wrong polarity. Often, modules like that one include a reverse-connected diode across the input for reverse polarity protection. When you apply voltage with the wrong polarity, the diode...
  16. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    I've had a look at your code and discovered a major problem with it. It doesn't have any comments! Comments are essential, not just so other people can understand what the program does and how it works, but so that YOU can understand what it does and how it works, when you come back in six...
  17. KrisBlueNZ

    Current Direction

    Yes, I believe so. As the resistance of the parallel wire approaches zero, the amount of current flowing in the parallel resistor approaches zero as well. I don't know how you would describe the situation when the resistance is actually exactly zero; it depends on how you deal with division by...
  18. KrisBlueNZ

    Trouble with tribbles.. erm, timers.

    I don't have time to look at the code now, but I did a write-up about multi-tasking approaches at https://www.electronicspoint.com/required-delay-before-function-execution-t254903.html#post1512974 which may be helpful. I don't know of any offhand, but Google will find them for you if you can...
  19. KrisBlueNZ

    60 cycle hum

    If it's Cheap and Chinese, there's also the possibility that it wasn't assembled or soldered correctly. Look for missing components (by comparing it with the other unit) or solder missing or shorting where it shouldn't. If it's nothing obvious, take the chassis out and post a few photos here...
  20. KrisBlueNZ

    Simple parallel EEPROM programmer

    Good call :-)
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