Need circuit to produce 3 modes of audible confirmation

"Jason S" schreef in bericht news:439972f7 snipped-for-privacy@news.iprimus.com.au...

A PIC, even the smallest one is the most simple solution... once you can program it and program it. That's to say you need the skills and the equipment. If you like to make more of this type of circuits the investment wil sure pay off. Otherwise, a bunch of 555s may do the job as well.

- One astable (1) for the beep timing (let's say 0.4s on and 0.4s off once enabled)

- One monostable (1). Triggered by 'ON', enabling the astable (1) for 0.6s.

- One monostable (2). Triggered by 'OFF', enabling the astable (1) for 1.4s.

- One monostable (3). Triggered by 'ERROR', enabling the astable (1) for

2.2s.

- One astable (2) optional to produce a 1kHz beebfrequency once enabled by astable (1).

The most straightforward way to control astable(1) by the three monostables is a 3-input OR-gate (or NAND).

petrus bitbyter

"petrus bitbyter" schreef in bericht news:4399c38d$0$20780$ snipped-for-privacy@dreader25.news.xs4all.nl...

Oops, forget the NAND as you have no inverted outputs.

petrus bitbyter

OK, fair enough. I haven't personally attacked that hurdle, because I haven't really had that much incentive to chase after it. :-)

This is true - I made an SOS light once with about three chips - it was very much like those amber flashers that you see on the "Under Construction" signs, but this flashed "SOS" in Morse code

_ _ _ ___ ___ ___ _ _ _ _ ___| |_| |_| |_| |_| |_| |_| |_| |_| |_____________| |_ ... etc.

I used "data selector logic" lifted almost directly from Don Lancaster's TTL Cookbook.

The point of the project was, if you see flashing amber lights, on-off-on- off, etc, then it means mechanical difficulties. If you see the SOS light, it means a person in distress, so hurry up and call the ambulance. The product never got off the ground, but it was fun to design!

And I got paid. :-)

Cheers! Rich

Well, Rich,

I have to disagree on some points. As for a development system, you can find all on the net. For free. A programmer (the equipment, not the man) can be build for much less then $100. Free schematics and plans on the net. The investment will be in time. Knowing nothing of PICS is not a real problem but knowing nothing of micros and programming is a pretty high hurdle.

Another way I pointed out in a previous posting. If you use NE556 you can do with two or three chips (and a pot of resistors and caps :)

petrus bitbyter

I need to make a circuit that will produce either one, two or three short consecutive beeps depending on the input signal it recieves. For example:

Input 1 = One beep (could mean 'ON'). Input 2 = Two beeps (could mean 'OFF'). Input 3 = Three beeps (could mean 'ERROR')..

This is just an example. The 3rd one is not critical, but would be nice.

I want to be able to add it to practically any circuit which will provide audible confirmation of the circuit's current operation. I was thinking of using a PIC to do this, but is last resort (as I know absolutely nothing about them).

Has anyone got any suggestions?

Thanks.

I made a flashing bike light for my daughter in NYC using a red 1-watt Luxeon. She said she wanted bright. This sucker is bright!

I thought about having it flash: di di di di dah ..... dah dah di dah (4Q) to show a little New Yawk attitude -- but I didn't have the microcontroller ability to do that. Still don't but hope to soon. Heck, a SOT23-6 10Fxxx PIC would have taken less space than the 555 I used.

How about a CMOS 22V10 and a couple of RCs ?

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kensmith@rahul.net   forging knowledge

I get two logic chips, a 555, three diodes, one transistor, two resistors, the usual 2xR+C 555 astable timing, and a beeper: View in a fixed-width font such as Courier.

. . .------------------------------------------------------. . | | . | 3x 1N4148 | . | --------- | . IN 1----------------------+-|>|--+-[100K]-+----|RST OUT|----+ . | | | | | | | . IN 2--------------------+-|-|>|--+ | | 555 | | . | | | | | | | | . IN 3--------------------|-|-|>|--+ | | ASTABLE | BEEPER . | | | | | | | | . .-|----------------|-|------+ | | ON TIME | | . | | | | | | | =BEEP | | . | | | | [100K] | | OFF TIME| --- . | | 4017 | | | | | 1/2 BEEP| /// . | | -------- | | | | --------- . | | | Q0| | | --- \\| . | | |-- | | | /// 2N3904|---. . | '---|CE | | |

That's nonsense!- why do that when you can use the serial port on your PC.

No need to breadboard, these parts are too familiar. I did a confirmation check in mixed-mode SPICE and it works as expected. What kind of beeper are you working with?- there are several types- some are self-oscillating so that all the 555 has to do is apply voltage to it, others are just transducers and you have to supply the oscillatory input. In the second case you will have to make a 555 oscillator at

2-3KHz to drive it, and use the 555 on the schematic to drive its RST input- gating it on and off. I suppose a beep duration of 500ms ON and 250ms OFF should be about right- and that would be something like this: View in a fixed-width font such as Courier.

. . . TO ----|-----|----|RST OUT|-+-> TO BEEPER . LOGIC | | | | . . | +----|THRESH | | . | | | | | . | +----|TRIG DIS|-. | . | + | | | | | . | === | GND | | | . | 1U| +------------+ | | . | | | | | . | '-----------+ | | . | | | | . | GND | | . | | | . '-------------------------' | . | . | . | . .---------------------------------' . | . | . | . | 5V . | | . .----|---+--[27K]----+ . | | | | . | | [270K] +------------+ . | | | | VCC | . | | | | | . | '---|----|RST OUT|--------. . | | | | | . | +----|THRESH | | . | | | | | . | +----|TRIG DIS|-. PIEZO . | | | | | | . | === | GND | | | . | 1n| +------------+ | | . | | | | | . | '-----------+-------|------' . | | | . | GND | . | | . '---------------------------- . .

In my never ending battle to save parts I suggest:

Modified version:

BTW: I'd use a ceramic for the 1uF. There is a lot less risk of putting it in backwards that way.

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kensmith@rahul.net   forging knowledge

Hi Fred, thanks for the schematic - very helpful. Did you come up with that yourself? Just out of curiosity, have you tested the circuit? I haven't had a chance to build it yet, but can't wait to see how it works - and sounds like it will do the job. Most others have mentioned a PIC but I haven't got the time for that. I will let you know how I went with your schematic. Thanks again.

Jase.

Thanks to everyone who has made suggestions.

Jase.

And here I opened your post on the outside chance you would tell me something new. I don't really care for the 50-50 beep alert as it lacks sufficient enthusiasm in my estimation, so I will splurge and use the additional resistor thank you very much. But here's something novel- a diode used to practically eliminate the extra long first pulse effect. SPICE says it works, and I don't see why the real world should disagree as long as the output is effectively unloaded. The price you pay is loss of the ratiometric switching thresholds but that is not required in the majority of applications. You can do whatever you want with the piezo astable- it's neither here nor there. View in a fixed-width font such as Courier.

. . . TO ----------|RST OUT|---------+ . LOGIC | | | | | . CKT +----|THRESH | | | . | | | | | . +----|TRIG DIS|---' | . | | | | . | | | 1N4148 | . | | CONT|--|>|----+ . | | | | . + | | | | . === | GND | | . 1U| +------------+ | . | | | . '-----------+ | . | | . GND | . \\|/ . . to RST of . piezo astable . .

This will work too:

When RST goes high, the 0.5u puts the trigger at Vcc/3.

BTW: You can make pulsing beep with just one 555. Unfortunately, there is no easy way to do the CD4017 running from it. It looks like this:

100K 10K 100K 10K 1u Vcc -/\\/\\/-+-/\\/\\-+-/\\/\\-+---+--/\\/\\--!!--+---- Output ! ! ! ! ! ! 10u --- 0.1--- ! ! ! --- --- ! ! ! ! ! +- ! ! GND GND ! ! ! ! ! ! ! -------------------------------------- ! D T T Q ! ! i r h ! ! s g r !

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kensmith@rahul.net   forging knowledge

Jason S wrote: > Hi Fred, >

You are using the bipolar 555 and the typical RST pin current is listed as 0.1mA, for which the 100K resistors are much too high. If you want to keep the signal input impedance of the circuit high then you will have to use the circuit attached below or go to a CMOS 555.

If live inputs while the circuit is unpowered are a real possibility then you should put a 10K in series with the input of the NAND driving the 4017 RST input, and you can add a C+R from VCC to one input of that NAND for a power on RST if you don't like the beeps.

Yep-

Yep-

Yep-

Either go with a CMOS 555 or use circuit below.

It's only personal preference- if you're satisfied with the sound then go with it.

As I said- either go with CMOS 555 and original circuit, or keep your bipolar 555 and mod the circuit like shown below. You add a pull-up resistor from 555 RST to Vcc, the NAND driver for the 4017 RST also drives the transistor base OR circuit through a 10K and a 10K replaces the 100K in the other drivers of the base circuit. A power on RC has been added to RST the 4017 at turn-on. The operation is basically the same except that now when an IN goes high, it indirectly causes 555 RST high through the NAND+ transistor combination, instead of directly. The

555 is now RST after required number of beeps OR when the inputs are removed. View in a fixed-width font such as Courier.

. . 5V . 1U | . GND--||--+----[100K]-------+ . | | . .------------------------------------------------------. . | | _ | | . | 3x 1N4148 '---| \\ [10K] | . | | o-. | --------- | . IN 1------[10K]--+-|>|--+---|_/ | +----|RST OUT|----+ . | | | | | | | | . IN 2------[10K]+-|-|>|--+ | | | 555 | | . | | | | | | | | | . IN 3-----------|-|-|>|--+ | | | ASTABLE | BEEPER . | | | | | | | | | . | | | [100K] | | | ON TIME | | . | | | | | | | =BEEP | | . | | | GND | | | OFF TIME| GND . | | | | | | 1/2 BEEP| . | | | | | --------- . | | | | | . | | | | | . | | '--------. | | . | '--------. | | | . | | | | | . .---------------------------+-[10K]--------. . | | | | | | . | | --4017-- | | | | . | | | Q0| | | \\| | . | | |-- | | | 2N3904|---+ . | '---|CE | | |

That would be 10K in series with each IN line: View in a fixed-width font such as Courier.

. . 5V . 1U | . GND--||--+----[100K]-------+ . | | . .------------------------------------------------------. . | | _ | | . | 3x 1N4148 '---| \\ [10K] | . | | o-. | --------- | . IN 1-----[10K]---+-|>|--+---|_/ | +----|RST OUT|----+ . | | | | | | | | . IN 2-----[10K]-+-|-|>|--+ | | | 555 | | . | | | | | | | | | . IN 3-----[10K]-|-|-|>|--+ | | | ASTABLE | BEEPER . | | | | | | | | | . | | | [100K] | | | ON TIME | | . | | | | | | | =BEEP | | . | | | GND | | | OFF TIME| GND . | | | | | | 1/2 BEEP| . | | | | | --------- . | | | | | . | | | | | . | | '--------. | | . | '--------. | | | . | | | | | . .---------------------------+-[10K]--------. . | | | | | | . | | --4017-- | | | | . | | | Q0| | | \\| | . | | |-- | | | 2N3904|---+ . | '---|CE | | |

You can't let the inputs 1 & 2 "float" since these connect to the logic NANDs on the output of counter, the logic requires well-defined voltage levels , either H or L, voltages in between cause them to act up. You have to put pulldowns to GND there- say 1M ohms- put 1M's right at the input to the circuit on all IN's for consistency. Where are your inputs coming from anyway? The diodes are a logic OR and they are in the correct spot.

Hi Fred,

To answer your question, I will be using a self-driven piezo buzzer which DOES NOT oscillate (I thought that was what I was supposed to use?), so the

555 will apply power to it when a beep is required (via the usual resistor/transistor/diode arrangement).

I did a breadboard test of your original schematic this morning, and it seems to be operating PARTIALLY o.k - Not sure if I did anything wrong - there's wires everywhere! arrghhh!. There's bit of a problem that I have encountered....

Problem # 1 : The 555's outpin pin is high if there are no inputs connected (standby) - isn't it supposed to be low? As soon as I connect an output, it works o.k but as soon as the input is disconnected (when the 4017 resets), the 555's output pin goes high again and stays high (causing the buzzer to sound continuously!). Not sure what to do here Fred~! I used a logic probe and the NAND gate that connects to the RST pin of the 4017 intermittently gives half high half low, and found that the circuit then doesn't 'reset'. Funny how it's only sometimes.

Problem # 2: Also if there is already an input connected BEFORE I turn the power on to the circuit, buzzer will beep 7, 8 or 9 times before it stops! i.e. Input 1 = 7 beeps. Input 2 = 8 beeps. Input 3 = 9 beeps. However, the 4017 seems to be going through only 1 cycle (which is good), because according to the logic probe, each of the outputs go 'high' only once. Weird.

Let me confirm the following:

1) All gates used are of NAND type (4011). Note that your text mentioned 'AND'd'!). 2) The 4017's CLK/Clock pin is connected to the positive rail at all times. ??? 3) Output from the 555 is connected to the CE/Clock Enable pin of the 4017. 4) The inputs - finding that circuit doesn't work properly if any unused input is 'floating' (i.e. not connected to ground). Are the diodes in the correct spot? 5) What's the deal of not having a square wave for the 555 output? Does it matter? My output seems pretty square.

Thanks again,

Jason.