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What is a 'High/Low Level Trigger'?

Discussion in 'General Electronics Discussion' started by Paul K, Dec 5, 2015.

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  1. Paul K

    Paul K

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    Dec 5, 2015
    Hi All! I've been building computers and other electronic gadgets for years, but have just started to get into the level of the "micro-electonics..." I'm attempting to build a little motion activated audio player (primarily to scare woodpeckers off my house) and I'm stuck on how to make this ISD1820 play the recorded audio when the motion detector is triggered.

    The PIR assembly I have feeds power for 1 minute after motion stops. I would like for the audio start with when the PIR kicks off and to loop during the entire PIR cycle. (and the PIR would also trigger power to the ISD1820 board) Evidently looping is possible when the level trigger changes from low to high and then looping stops when it goes back to low. I think where I'm stuck is that I don't know what the "High Level Trigger" is supposed to be.

    So if this makes sense to anyone and you know what I need to do, please don't hesitate to share! I would be most grateful!

    Here is what I am working with:
    http://www.amazon.com/gp/product/B00HJ6ZZBM?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00
    http://www.amazon.com/gp/product/B010ND0KDK?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00
     
  2. Bluejets

    Bluejets

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    Oct 5, 2014
    Cannot see any reference to what you describe ....can you be more specific on where you saw the level trigger info?
    Normally it means just a pulse which goes high for a moment and then low again.
    High is pos rail voltage( or thereabouts) , low is negative rail voltage (or thereabouts).In this instance it could also be transition sensitive.(that's how your description reads)
     
  3. dorke

    dorke

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    Jun 20, 2015
    Here you have the user manual of the ISD18B20
    The voltage to the player is VCC=2.4-5.5VDC you don't need to switch it.
    You need to use(switch) PlayL input ,Level-activated control.
    switching it to High(=VCC) will play, taking it back Low will stop the playback.
    Also, activate the "REPEAT" switch.

    What the PIR is switching isn't clear to me(closes contacts? feeds it's voltage? other?)
    You have to take care that the voltage you feed to the PlayL input of the ISD18B20 will not be above it's VCC!
    If needed lower it with resistor voltage divider!
     
    Last edited: Dec 6, 2015
  4. Paul K

    Paul K

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    Dec 5, 2015
    Hi! Thanks for the response- a doc on the isd1820 can be found here: http://www.hackerstore.nl/PDFs/EIM353_ISD1820_Module_Manual_V01.pdf On page 3 it references high and low level triggers. Is that just passing the 5v power to the PlayL pin?
     
  5. Paul K

    Paul K

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    Dec 5, 2015
    Hi! The PIR is actually 12V and triggers an LED- since posting this earlier today, I realized I need to step that down for the 1820... I read those instructions, but, sadly didn't quite understand the terminology. But if I understand you, you're saying that if, for example, I had a 3-AA battery pack, and I connected the (-) to gnd and (+) to VCC, then I could jump the (+) to PlayL and that would give me playback?
     
  6. dorke

    dorke

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    Jun 20, 2015
    Yes exactly.:)
     
  7. Paul K

    Paul K

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    Dec 5, 2015
    Well, thank you! That was exactly what I needed! It turns out I have the ISD1820 like this: http://www.ptshop.cz/fotky48100/fotov/_ps_274ISD1820_voice_rec_module_ug.pdf, not the ISD18B20 as in the original doc I posted. The basic difference is that my version doesn't have the switches. Instead, there are jumpers for Feed Thru and Endless Play... It turns out that all I needed to do was apply the VCC and GND and then short the P-E pin with a jumper to get the endless looping. I may have caught a bug with this project... I'm already thinking of ways to expand the project.

    Thanks again for your help! Very much appreciated!
     
  8. Bluejets

    Bluejets

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    Oct 5, 2014
    Getting your details straight in the beginning is a big help to everyone:)
     
  9. CDRIVE

    CDRIVE Hauling 10' pipe on a Trek Shift3

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    May 8, 2012
    Paul, I read your manual. Isn't reading Chinese Pigeon English such fun!? :D Fortunately it was much easier to decipher than many I've read.

    BTW: Welcome to EP!

    Paul, if you catch the bug (as you say) you will undoubtedly be posting often. In that case it will be unavoidable for you not to run into my nephew Marty. He's a smart lad but just a tad goofy. Not his fault though. As a child he fell off a construction site roof onto a length of 1/2 inch rebar; which surgeons can't remove from his head. The doctors are hopeful that it will eventually just rust away. When he posts to one of your topics please just humor him .

    Chris
     
    Martaine2005 likes this.
  10. dorke

    dorke

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    Jun 20, 2015
    Paul,
    your welcome.
    There is one issue though.
    The PIR is intended to identify movement of humans,will it work with woodpeckers(much smaller)?
    If at all,at what distance?
     
  11. Bluejets

    Bluejets

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    Oct 5, 2014
    Depends on the PIR.
    We often get problem installations with respect to trees and clothes lines etc.
    Even though the units we use have sensitivity adjustment, we tend to avoid the above like the plague as it tends to give false triggering.
    i.e. wind blows the branches.........receiver detects hot spots adjacent
     
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