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  • Originally posted by pure gold View Post
    new pcb drawing and discriminative hex
    Nobody say anything about the above circuit...?
    Is that perfect?
    What about the syncing resistor? What value resistor do you suggest?

    Please tell us if there's anything else... I don't want to change it again later...


    Regards,
    1843

    Comment


    • if you really want something to add to circuit , put 4 S&H caps controlled by mux and analog ADC .
      at least you need 2 of them to get samples free from other surrounding EM noises. it is better to subtract second sample which will be taken after end of delay like 300us after TX off time.
      and to get precision second or third samples S&H unit is a must.

      Comment


      • Originally posted by okantex View Post
        if you really want something to add to circuit , put 4 S&H caps controlled by mux and analog ADC .
        at least you need 2 of them to get samples free from other surrounding EM noises. it is better to subtract second sample which will be taken after end of delay like 300us after TX off time.
        and to get precision second or third samples S&H unit is a must.
        No, I meant if ther's any defect... and fortunately it seems has no problem!
        I'm not going to add analog switchs, S&H, etc.

        Comment


        • Hi 1843,

          Please help us,
          Your MD produce pulses with atmega8 timers or another ways?
          what is your MD pulses frequency and pulse width ????
          I am waiting for your answer...
          with best regards.
          zenit52

          Comment


          • Hi 1843 ,
            are you sure about analog S&H unit , it has advantages , first it will compansate parasitics and give you average value.
            second if you want to have second or third samples from same curve , without S&H unit you can not get precision second or third sample , cause converting time of first sample varies according to different stuations of targets.
            but if you say you will do discrimination studies over delay time ratios ,that is okay.
            but otherwwise..........

            btw schematic is geting closer to PD3200 ,just it uses IC for S&H , still I cold not understand why did the designer use it there?
            regards

            Comment


            • pfd schema

              http://md4u.ru/forum/download.php?id=1969
              http://www.mikronbg.com/Stinger2.html

              Comment


              • multi frequency MD

                http://i10.tinypic.com/4bi1zpi.gif

                Comment


                • Originally posted by okantex View Post
                  ...
                  without S&H unit you can not get precision second or third sample , cause converting time of first sample varies according to different stuations of targets.
                  ...
                  The ATmega8 has Hardware Timers, I guess these can be used here.

                  Comment


                  • Originally posted by zenit52 View Post
                    Hi 1843,

                    Please help us,
                    Your MD produce pulses with atmega8 timers or another ways?
                    what is your MD pulses frequency and pulse width ????
                    I am waiting for your answer...
                    with best regards.
                    zenit52
                    Sorry for late...
                    See here
                    The codes are written in BASIC by our friend SISCO. I recommend you first write simple codes...

                    About PI-111:
                    PW: 60us and 240us
                    Freq: 1KHz

                    I can't visit the forum very often... I have a lot to do.

                    Regards,
                    1843

                    Comment


                    • help me

                      sisco help me...................................!!!!!!!!!!!!! !!!!!!!!!!!!!!

                      Comment


                      • re:sisco

                        Max , your idea about timing , I want first make new device for test your

                        idea but think and decide first test this timing on my minipuls.

                        so erase minipuls ATMEGA8 and programmed by new program (1KHz ,100us

                        PW ,15us , 45us first delay , 200us interdelay and 45us second delay) and

                        test , what you think ?

                        YES this work and I can detect GOLD with this timing.

                        this is my programm writed on ATMEAG8.

                        evrey step =3.75us for example A = 27 mean this time is 101.25 us (IN THIS TIME MOS-FET IS ON)

                        $regfile = "m8def.dat"
                        $crystal = 8000000
                        Config Timer1 = Timer , Prescale = 1
                        Stop Timer1
                        Config Portb = Output
                        Config Portd = Output
                        Portb.1 = 0
                        Portd.6 = 0
                        Portd.7 = 0
                        Dim A As Word

                        Startline1:
                        Start Timer1
                        A = 0
                        Portb.1 = 1
                        Do
                        A = A + 1
                        Loop Until A = 27
                        Portb.1 = 0
                        A = 0
                        Do
                        A = A + 1
                        Loop Until A = 4
                        A = 0
                        Portd.6 = 1
                        Do
                        A = A + 1
                        Loop Until A = 12
                        A = 0
                        Portd.6 = 0
                        Do
                        A = A + 1
                        Loop Until A = 53
                        A = 0
                        Portd.7 = 1
                        Do
                        A = A + 1
                        Loop Until A = 12
                        A = 0
                        Portd.7 = 0
                        Do
                        A = A + 1
                        Loop Until A = 158
                        Stop Timer1
                        Goto Startline1


                        TIMING:
                        Frequncy = 1001.5 Hz
                        PW(ON PULSE) = 101.25us
                        delay= 15us
                        first delay = 45us
                        interdelay = 198.75us
                        second delay = 45us
                        OFF PULSE = 592.5us

                        FOR 1000HZ:ON Pulse is 100us so OFF pulse must 900us calculate = (15us+45us+198.75us+45us)-900us =~595us
                        by sisco
                        http://www.geotech1.com/forums/showt...t=sisco&page=2

                        Comment


                        • avr programmers....

                          Originally posted by Qiaozhi View Post
                          1843 was not banned. Carl was adding a spammer's address to the blocked list, but he accidentally added a wild card in the wrong place ... and banned everybody.

                          You obviously missed Carl's humble apology that was present at the top of the forums yesterday. It has since been removed.

                          The forums are now back in operation.
                          Hi,
                          was very wild wildcard then...

                          uhm... coming back to the topic here... I think, like in the clone-pi case, that the atmega8 is still actractive to be employed in a PI detector.

                          I think there's enough for timing and a bit of computation in it... to do something useful.

                          Also, for people who don't know (cause I'm sure Qiaozhi knows all that stuff) the ATMEL's are really dirty/cheap to program, both in Windows OS or others (like unix/linux/bsd/mac os etc etc) the reasons are many, but mostly that often a simple parallel cable is enough to do everything. But I will say ... you could use also a serial port, an USB and even a wifi device (possibly even an old toaster) to burn any avr!

                          For people who knows little about here's a link that can explain... most of troubles and very easy and cheap solutions. BTW Atmel's are also very easy to in-circuit program with same stuff described... a cable! and a PC! that's everything you need.

                          Look here to have an idea of what you may need to program it... :
                          http://my.opera.com/CrazyTerabyte/bl...troller-part-2

                          As you can see that's not much.... a couple of connectors, some 1K resistors or less, some wires... that's everything you need to burn code in any atmega8 (and other avr chips too).

                          That's all... find avrdude software (version right for your OS) and burn your chips for a bunch of free.

                          Kind regards,
                          Max

                          Comment


                          • Originally posted by Aziz View Post
                            Hi 1843,

                            it is quite surprizing, that you can achieve such a sensitivity with the internal 10-bit ADC resolution of the ATmega8.

                            Aziz
                            Yes! that's why I decided to share it with people. I'm very interested to see how much depth it will go with the new schematic.

                            Best regards,
                            1843

                            Comment


                            • Originally posted by Max View Post
                              Hi,
                              Look here to have an idea of what you may need to program it... :
                              http://my.opera.com/CrazyTerabyte/bl...troller-part-2
                              Yes, and guess what? He's Brazilian!
                              Land of brilliant minds.
                              Any doubt Brazil will lead the world after US and Europe almost broke it financially?

                              By the way Max, welcome back to GEOSKEPTHIC forums. I missed your Irish Whiskey!
                              Any findings with the PD yet?
                              Best regards.

                              Comment


                              • hung-mung-fung-chung your posts are so funny! brasil is very poor country. pitty and sorry, but you will suffer from economic crise more and harder than many countries in eu. so dont fool yourself, brasil will never become leading country, except maybe in soccer and carnivals. you said author is brasilian...so what? every countr and every nation do have brilliant minds and good people - thank God to that. aitn not generally bad country or bad nation or good country and good nation. every nation has bad and good examples for everything. you are so funny..ha,ha,ha! lrl does not work anymore? so you are looking to harass on some other subject here? ha,ha,ha!

                                Comment

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