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Thread: Advanced Water Level Indicator

  1. #21
    Junior Member Newbie Blacksteel's Avatar
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    Quote Originally Posted by docel View Post
    Hmmmm... looks like a Water level Detector Robot...

    There are 2 practical ways of doin this : RF & Voice.
    Everyones covered the RF part, so let me tell you about the Voice part.

    The Tx part is a 555 timer Ic ( CMOS is better suited for its stability) as a multivibrator. The' R' is an LDR in a pipe. at the top end and an LED at the bottom. Water in the pipe will attenuate the light falling on the LDR and change the OP of the 555 at pin 3. If the RC is calculated for audio frequencies, the 555 will sing different notes at different water levels. Connect pin 3 to the cheapest 433mhz RF TX.
    The RX can be connected to a Micro ( if you are a coding buff) or to a set of 567 tone decoder ICs.
    The 567 IC ( Read the datasheet ) will respond to specific frequencies by a tunable Preset resistance. You can either get a digital o/p for specific levels with any number of 567s in parallel or get a continuous audio tone from the RX, depending on the level of water.
    An Audio Freq to Voltage converter circuit can give you a LED bargraph visual output. There are many Simple discrete circuits to hi-funda DSP algos for this. The choice is yours.

    ps: it can be a simple 2wires from the 555 to the 567 too. dont worry about cable power drop- it is good to a cool 1/2Kms, if you use a 12v at both ends.
    Man, thats one crazy idea!.. I'm gonna try that out on my existing waterlevel controller system. Dunno if my "cheap" RF modules with work at that baud, but if it works I'll post it on my LMR page!
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  2. #22
    Administrator T-1000 vikas's Avatar
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    Wired we do not have problem of batteries , RF batteries i required.

    What is the current usage of your system ? and which batteries are you using , maybe make it solar powered .
    Vikas Patial

  3. #23
    Administrator T-1000 vikas's Avatar
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    Looks like i need to build it, Rather than tone decoder will use frequency counter and LCD and have actual water levels. The 3/4 point contact sensors are simply too unreliable and fail often, while giving no real indication of water level at any given point.
    Vikas Patial

  4. #24
    Super Moderator T-1000 docel's Avatar
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    Vikas.....!
    You mean you're REALLY gonna make it ?
    Nice to hear that - was wondering how come no one took the bait for so many months
    Good luck!!
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

  5. #25
    Member Advanced User MGear's Avatar
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    Lightbulb Water Level Indicator

    I would really like to see your version Vikas.
    What Docel had suggested didn't turn out to be my cup of tea. So I built the system my 'easy' way. Which turned out to be a costly affair. The recent reply made me look for my files in the backup again, so am attaching the schematics.
    This design was very much to imitate the '1-wire' protocol. But was not efficient by any standards.
    Also I wanted to run the Tx on parasite power mode, which I couldn't. Both the boards have separate power supply.

    What do you think of it, Vikas and Docel ?
    Attached Images Attached Images

  6. #26
    Administrator T-1000 vikas's Avatar
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    Yes , our new house has 3 watertanks , i dont feel like running around and getting shouted at other than wasting water.

    I thinking of the sensor like this -

    LDR at top of PVC with 555 , Ultra Bright LED at bottom of PVC pipe , so when water fills up it will change the frequency. Though im thinking sediment might settle on the led even if i raise it a little and put some meshing in holes where water enters pvc.

    Second I was also thinking of putting a buoy with a mirror on top inside the PVC , this way sediment will not settle and it will always be clean. In this case LDR and LED will be at top with a separator in b/w.

    Is the frequency response linear ?

    Which would be better ?

    For uC I was thinking of 89v51rd2 , but it does not have any eeprom and IAP seems wagely documented and not sure if its worth the effort .

    Second in choice is PIC16F1938 as i already have lots of tools for pics including ICD and pickits etc

    Atmega's seems expensive ... even for 8 kb variant.

    Arms ... seem overpowered .
    Vikas Patial

  7. #27
    Administrator T-1000 vikas's Avatar
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    For power to sensor , i would use cheap 3 wire setup , 2 for power and 1 for frequency out from 555. Want to keep low cost and maybe make a open source water level meter .

    Display will have a 16x2 lcd with 4 tank setup and control using 4 tact buttons.
    Vikas Patial

  8. #28
    Super Moderator T-1000 docel's Avatar
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    Yes... I have done that too. Used one of my ADC Atmega8 LFR boards as sensor/ processor
    The mirror on top gets fogged too.
    Now I use a Acrylic Rod/tube with the LDR and LED embedded in a drilled hole. No Water fogging although regular wiping is needed once a month or so. Need some funny juggling of the code to get a linear output....
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

  9. #29
    Administrator T-1000 vikas's Avatar
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    Hmm , if things require maintainance ... im not upto the task , need something more reliable

    Something similar

    http://howmuchsnow.com/waterlevel/ , but using Sharp ranging sensors , similar can be done by us ?

    Inplace of a mirror will a ping pong ball work ? So the selaed tube is not affected by water fogging ?
    Vikas Patial

  10. #30
    Super Moderator T-1000 docel's Avatar
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    Anything needs some maintenance Vikas. I have used the sharp sensor with great results but even that gets fogged and gets spoilt. IF you need any accuracy, you have to clean it almost everyday too. Also, The plastic lens somehow reacts with water and becoms useless in time.
    The simplest is what i'm using. IR LFR sensor/processor with ADC. This is a reflective, non contact method, You will have to keep the water condensation at a minimum. One way is to put a small DVD drive Fan which will evaporate the fogging moisture.
    Mind you - All these were part of my school projects with kids and we never bothered about accuracy at all. just as a comparative indicator with a fair amount of accuracy say +/- 3" .
    docel
    ^Anything is possible..
    after YOU prove it!!

    http://bangalorerobotics.tripod.com

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