EPE Earth Resistivity Logger

Discussion in 'Embedded Systems and Microcontrollers' started by macke, May 4, 2016.

  1. macke

    Thread Starter Member

    Oct 12, 2014
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    Hi I have just completed the build of an Earth Resistivity Logger from an article in the EPE magazine of 2003. I have 2 problems with it. If I upload the article and circuit diagram is there anybody willing to help me fault find it. I am a bit of a newbie.

    Ken
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Have you got copyright clearance to upload the article?
     
  3. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Hi good point. I'm not sure. Best just forget it I guess.
    Ken
     
  4. BR-549

    Well-Known Member

    Sep 22, 2013
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    Don't worry about copyright. As long as you are not making money with it or claiming authorship.

    If someone tries to sue.....countersue for advertising fee. Because, only the copyrighter benefited.

    I need to see the circuit.
     
    Sensacell likes this.
  5. macke

    Thread Starter Member

    Oct 12, 2014
    65
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    Hi thank you for that. I checked on the EPE site and it is not listed on there now as it is so old (2003). It its also readily available for download on the web in quite a number of places. I have attached it to this message.
    Thank you for your offer of help.

    Moderators note:
    The post linking to an un-authorized copy of the article has been removed because displaying it is a violation of the user agreement.

    Below is a link to the publisher's information on the article.
    http://www.epemag.net/downloads/PICS/EarthRes_2003/earth-res2003t
     
    Last edited by a moderator: May 12, 2016
  6. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    I have the EEPROM clearing routine working now, but still left with the odd reading on the test position. I have swapped out the PIC, but it is just the same
     
  7. BR-549

    Well-Known Member

    Sep 22, 2013
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    Ok macke.

    I scanned over your article. I haven't programmed a uprossesor in decades, other than blinkin a led.

    And I have never used a PIC, but you couldn't find better pic experts than on this site.

    You have not stated your problem yet, but the coders will need to see your code.

    You said you had 2 problems, what are they?
     
  8. BR-549

    Well-Known Member

    Sep 22, 2013
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    Ok. Do you think it's a coding problem?
     
  9. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Hi no I dont think it is a coding problem. I am sort of suspecting the quad op amp at the moment. The PIC monitors the voltage on the outputs of IC4a and IC4b in the test position. IC4c and IC4d are the ones used in the normal/run position and the readings on there appear to be ok.
     
  10. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Attached is the code used.
     
  11. BR-549

    Well-Known Member

    Sep 22, 2013
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    I would suggest the EEPROM problem first. But I'm no expert.

    I can't relate to either of your problems........not familiar with chip.

    Is it possible to find others who have built it, at that site?

    And I would ask a moderator to move this thread over to the embedded systems forum.

    The PIC guys over there are great.
     
  12. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Hi i will do as you suggest. I did a test in the normal position on 20 readings and saved each one the EEPROM. With the co-ordinate switches (+ and -) I can recall them all so it is certainly saving them. As I said previously I have also managed to get the EEPROM readings erased as well now, so it is only the problem in the test position.
     
    BR-549 likes this.
  13. BR-549

    Well-Known Member

    Sep 22, 2013
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    mache, I read your link.

    So are you saying that you can detect the signal at R16 and R17 when the transmitter is on, right?

    So, the eeprom problem is gone, You can store and recall measurements and you have the signal strength at the test points.

    Now you can practice the transmitter power and receiver gain for best readings.

    All op-amps are used in normal mode. You are getting the strength levels right?

    How are you coupling the transmitter and receiver?
     
  14. DickCappels

    Moderator

    Aug 21, 2008
    2,647
    632
    This is clearly copyright protected material and we don't have permission to republish it. I suggest that you post links to the online material instead of posting the material here.
     
  15. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Hi sorry about the delay, but i have been away for a few days. Anyway I have tested at R16 and R17 and I get -0.52 volts. Not really sure what I should get.
     
  16. macke

    Thread Starter Member

    Oct 12, 2014
    65
    2
    Please close my account.
     
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