PI CHIP

[hdphilip]

A surf PI home run......

moodz,
now that's cool

the Surf PI with the perfect computer interface, sweet!!!

This takes all of the guess work on setting up the timing!!!

The Mosfet damping would be icing on the cake!!




Philip

[moodz]

Great work Moodz
is there still a xtal on pins 9/10 ?

Ah ... I'll put that in on the next update ...:

Moodz

[6666]

Great work Moodz
is there still a xtal on pins 9/10 ?

[moodz]

Thanks Max ,

I will draw up a schematic on the weekend to indicate where the UNIPI chip can be connected in the surfPI.
The descrimination is a work in progress .... works fine on largish iron obejects but smaller targets like coins etc the results are not so clear ... in other words still working on that LOL. Have had alot of success with a novel coil damping method though that should add a bit more to the puzzle. ( I mean solve a bit of the puzzle LOL ).


moodz

Max ...as promised ... here is your schematic ... I have chopped out everything that was not needed ...could do a bit more chopping however I have preserved the critical parts that characterise the surfPI design ...
The schem is a modded rip from here ... http://www.geotech1.com/forums/showp...7&postcount=18 ... thanks to Jim.

moodz

[moodz]

Thanks Moodz
Will do ive just got to do the wireing now everythings mounted, the upgrade to 10 bit was actually on the designers web page just repeated what he purposed.
Im back to it after cooking sunday lunch for the family, thanks again.

Regards

OK Dave ... let us know how you go with it ... I see now what you were talking about ...I did not read that bit about the 10 bits I must of only read 9 of them ... ( a little joke there LOL ).

moodz.

[satdaveuk]

Hi Dave ... The circuit has alot of similarities to the surf PI however I am unfamiliar with the performance .... it may be good or bad ... maybe others on this board have some experience they could contribute ?? ....
Anyway I would advise you complete the project as per the design then maybe we could establish some benchmark measurements upon which to determine if any change we make might actually result in an improvement.
I am presuming the designer knew what he was about ... however straight up we can see that the sync feed for the synchronous power through C6 is right dodgy driving off the receive signal .... As for sampling at 10 bits I am not entirely sure what you mean by using a dual gang pot .. maybe you had some particular scheme in mind .

Cheers for now ... moodz

Thanks Moodz
Will do ive just got to do the wireing now everythings mounted, the upgrade to 10 bit was actually on the designers web page just repeated what he purposed.
Im back to it after cooking sunday lunch for the family, thanks again.

Regards

[moodz]

Hi Moodz
Ive almost finished this project based round the minipulse 3 with extra refinements, its based around the ATMEGA8-16AU chip.
If you notice on the circuit x9 at the moment is not used but by replacing the gain pot for a twin gang maybe bring it to 10bit sampling what do you think?.
Just wondering with mods wether it would be possible to maybe introduce your design based around the DISPIC30F4012 and or also your front end design, or infact any pointers to improve the design.
Anyway food for thought I know your a busy man, the full spec sheet is on the designers web page as bottom right hand corner of sch1.

thanks in advance

Regards

Hi Dave ... The circuit has alot of similarities to the surf PI however I am unfamiliar with the performance .... it may be good or bad ... maybe others on this board have some experience they could contribute ?? ....
Anyway I would advise you complete the project as per the design then maybe we could establish some benchmark measurements upon which to determine if any change we make might actually result in an improvement.
I am presuming the designer knew what he was about ... however straight up we can see that the sync feed for the synchronous power through C6 is right dodgy driving off the receive signal .... As for sampling at 10 bits I am not entirely sure what you mean by using a dual gang pot .. maybe you had some particular scheme in mind .

Cheers for now ... moodz

[satdaveuk]

Hi Moodz
Ive almost finished this project based round the minipulse 3 with extra refinements, its based around the ATMEGA8-16AU chip.
If you notice on the circuit x9 at the moment is not used but by replacing the gain pot for a twin gang maybe bring it to 10bit sampling what do you think?.
Just wondering with mods wether it would be possible to maybe introduce your design based around the DISPIC30F4012 and or also your front end design, or infact any pointers to improve the design.
Anyway food for thought I know your a busy man, the full spec sheet is on the designers web page as bottom right hand corner of sch1.

thanks in advance

Regards

[6666]

Hi Max
I built the complete stock Surf PI, and it works very well, with the R22 & R18 problem fixed
but as yet not much spare time to combine the the two projects, ( Pi chip & Surf pi)

[maxfly]

That sounds great,
I appreciate your time and patience,

Max

[moodz]

Thanks Moodz,

Here is the link to the Surf PI I have: http://www.silverdog.co.uk/shop/imag...ematic1_2A.JPG
Btw was your fet discrimination for a PI front end? Did you have any success?

Cheers, Max

Thanks Max ,

I will draw up a schematic on the weekend to indicate where the UNIPI chip can be connected in the surfPI.
The descrimination is a work in progress .... works fine on largish iron obejects but smaller targets like coins etc the results are not so clear ... in other words still working on that LOL. Have had alot of success with a novel coil damping method though that should add a bit more to the puzzle. ( I mean solve a bit of the puzzle LOL ).


moodz

[maxfly]

Thanks Moodz,

Here is the link to the Surf PI I have: http://www.silverdog.co.uk/shop/imag...ematic1_2A.JPG
Btw was your fet discrimination for a PI front end? Did you have any success?

Cheers, Max

[moodz]

I started out and built a Surf PI with the idea that I just wanted to have a detector at the end
but have found it quite addictive. Yes I want a detector at the end but can see myself moving onto something more complex. I know you mentioned that the Surf may not be the ideal platform, but I'd like to start with it. Do you know if 6666 got around to combining the two?
Let me know if it's worth me attempting this or not. I have accesss to an oscilloscope but have limited experience,

Cheers

OK ...your plan sounds as good as any other I have heard of LOL .....The boss is onto me at work at the moment but I will have a look at the surfPI circuit and work out at what points you can connect the UNIPI chip so you can play with the timings. Can you point me to the version of circuit for the surf PI you built.

moodz

[maxfly]

I started out and built a Surf PI with the idea that I just wanted to have a detector at the end
but have found it quite addictive. Yes I want a detector at the end but can see myself moving onto something more complex. I know you mentioned that the Surf may not be the ideal platform, but I'd like to start with it. Do you know if 6666 got around to combining the two?
Let me know if it's worth me attempting this or not. I have accesss to an oscilloscope but have limited experience,

Cheers

[moodz]

Hi moods,

Just wondering if you are able to supply one of your latest version chips pre-programmed, or even better some sort of kit? I'm only just starting into this type of work but am willing to give it a go! The capability is amazing.

Cheers

hiya Max ...are you an experimenter or do you expect to connect the PI chip up and get a detector. I am only asking because at the moment the PI chip generates pulses and can convert a voltage input to an audio signal. This is so experimenters can try out their own circuits. There is no complete circuit I can point to at the moment using this chip so it is mainly for experimenters.

Happy to help you out though ...

moodz