Kolero
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I was hoping to use the 555s that I have on hand, but I do like the sound of "simpler solution"!
Where might I find such a circuit?
3. The circuit can be designed so that once triggered, it completes the sequence and then waits for another trigger pulse. How long will the sensor pulse be?
So ... IF I were to go to a PIC10, what do I need? Could I program it with a tune, like the Westminster Quarters?A PIC10F204 could do everything, including the comparator.
In addition to the chip itself, you would need something to go between it and the computer to program it. There are a lot of programmers out there. You can either build one or buy one. Then just download Microchip's MPLAB IDE software and write the code.So ... IF I were to go to a PIC10, what do I need?
You're only limited by the amount of memory on the chip.Could I program it with a tune, like the Westminster Quarters?
At this point, with all the effort I've put into this circuit as it is, I think I'd like to see it through. I've bought too many parts to just go with one PICYes, a PIC would be a simple solution, but if you want to learn more about the hardware, then continue with that.
At this point, with all the effort I've put into this circuit as it is, I think I'd like to see it through. I've bought too many parts to just go with one PIC
If you're willing to design a circuit, I'd be more than happy to let you!
At the start of this thread, I just wanted 3 short beeps because I thought it was the simplest solution. Now, knowing how easy it is to make different notes with a Schmitt, I like the idea of a tune. The most common tune I can think of is Westminster Quarters, which is a total of 4 notes. But the top of the hour chime is too long, since this is just to alert someone that a customer has walked through the door. It should be noticeable, but short and not annoying. Really, just a Ding Dong doorbell sound would be fine. If you only want a Ding/Dong sound, then all you need is a single 74HC14.
While you work on that, I do have a question about it.. Right now I have one gate slowly oscillating, going to the 4017. I have the first 5 outputs on the 4017 going to LEDs, the 6th is empty and the 7th goes to reset. The LEDS light up in sequence nicely. I wanted to send the 6th output to another Schmitt gate to make a tone on the speaker. So the LEDS would go 1...2...3...4...5...(BEEP)...1... etc. Really, just so i could anticipate when the speaker should make a noise.
My question is.. the 74HC14 seems to take a negative input (capacitor from negative to the input). The 4017 sends a positive output. I can't just connect a capacitor from the 4017 to the 74HC14, can I? It doesn't seem right in my head, and it didn't work when I tried it either.
Yes, the current can only flow from anode to cathode (A to K).Thank you for the terminology. I'm used to having positive and negatives on a battery, but is the negative of a battery really 0v or Gnd?
It depends on whether you want a positive or negative supply. For a + supply, you connect the Neg side of the battery to Gnd.
For - supply. you connect the + side of the battery to Gnd.
The diode did the trick. So, if I understand this right.. current flows through a diode in one direction only, from the anode to the cathode. Since electricity follows the path of least resistance, the input of the Scmitt has two options: a capacitor or through the diode to Gnd. The capacitor is too much work, so it just flows through the diode. See below.
When the 4017 output reaches the diode, it's sending voltage across which gets stopped by the diode. The current from the Schmitt can't flow through the diode anymore because it is blocked by the positive current at the other end of the diode. Like driving down a one-way alley but now a truck is at the other end. So now the path of least resistance is through the capacitor and the tone is generated.
I don't think I'll need a tone to sound more than once, but I'm fascinated by this, so how would I do it? I'll post a circuit later.
Also, if I want to smooth out the tone, to make it less like a square wave, can that be done? Or to extend the last note and fade it out, like a "Ding Donnnngggg..." ? This is more complicated, so I'll deal with it later.
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