Universal PI Micro

[Ray-NM]

Way ahead of me

Looks like your are about a year ahead of what I am working on using a Stamp module. From the looks of it, it will be a pretty sophisticated controller for a detector. Thanks for sharing.
RayNM

[bugwhiskers]

UPIM update

The attached .pdf's show the revised schematic(the fat has been trimmed), and the PCB layout. The board is single sided with only a handful of jumpers (the small square pads) required.

The little orphan chip is the "G" sensor that still has to be plummed in via an adaptor board like the micro.

Resistor and cap values will be added after the prototype is running smoothly.

The PCB measures 3" * 3" square.
regards

bugwhiskers

[bugwhiskers]

Looks like your are about a year ahead of what I am working on using a Stamp module. From the looks of it, it will be a pretty sophisticated controller for a detector. Thanks for sharing.
RayNM

Hi Ray-NM,

Thanks for your interest in the project. It is essentially an engine to drive a lot of "standard" PI's. By standard I mean 2 JFET's or Analogue switches to toggle, an IRF740 MOSFET, requirement for a battery voltage doubling circuit to supply the +V of the OP Amps etc and the all important audio. It also has a screen which will allow those without the luxury of a CRO to see just what timings (in microseconds) their circuits are operating under.

Later I will make a set of drawings that will show where the UPIM is plumbed into the likes of the Hammerhead, Gary's PI and GoldscanIV.


regards

bugwhiskers

[bugwhiskers]

Display

The 16 character * 2 line backlit display is up and running. The UPIM daugher board can be seen in the middle of the large PCB.
I have decided to enlarge the daughter board and incorporate the other SMD device, the "G" sensor on it.

The numbers are leading zero blanked, ie you don't get 002 for the number 2.

regards
bugwhiskers

[bugwhiskers]

Bar graph & Joystick

The bar graph has been programmed in.
The digital range is 0-1023.

There are 16 characters * 5 vertical lines giving a range of only 80.
To give maximum sensitivity to the bar graph it has to have an offset from zero ie adjustable so the left most bar is just visible at the point of threshold.

The Joystick (or 5 buttons) are now being read, the following table shows the number generated by each button.

No button=255
CP(center press)=210
North=169
East=126
West=90
South=53

There is approximately 40 between each reading so noise won't give a false reading.

regards
bugwhiskers

[johnno]

upmd

Hi BW I counted 648?
is that what you where showing with the 5 buttons pressed? I hope Im not being picky as I have no Idea of how sensitive
this screen can be,...give or take some small % error.
johnno

[bugwhiskers]

Hi Johnno,

The 638 is just a number plonked on the screen to show where the digital signal strength will go. Only N,S,E,W and C(centre)will be recognised.
Pressing all the buttons at once will generate a very low number.

To allow for the offset mentioned in an earlier post there will be another adjustable number just to the right of the signal strength. It will allow the user to optimise/centralise the bar graph for maximum sensitivity.

Things have changed a bit since original conception. There will be 8 user adjustable settings:

1: Pulse width
2: Cycle time (time between pulses)
3: Delay 1 (first sample after pulse)
4: Width 1 (width of that sample)
5: Delay 2 (second sample delay after first sample)
6: Width 2(width of that sample)
7: Offset (for bar graph)
8: Low battery voltage (crucial if you are using LI/LiPo batteries)

There will be 3 screen pages.
7 and the bar graph are on the first page called Search.
1 to 6 are on the second page called Adjustment.
Battery Low Voltage adjustment will be on it's own page with room for more if needed.
With 8 user adjustable settings requiring 2 bytes each there will be room to store 32 sets of favoured adjustments in the on board 512 byte EEPROM (retained with power off) memory.

regards
bugwhiskers

[johnno]

wow

Sorry BW, I was not trying to correct maths,just That I dont understand the enormity of what you are creating..I will sit back and wait to see how your project pans out..(no pun on Gold panning).
Johnno

[Geo]

Perfect work . A few components yet and we have a very good PI detector with a lot of adjustable parameters. When i see projects as this i am angry with myself because i never learned to program microcontrolers
Congratulations bugwhiskers
My Regards

[Qiaozhi]

When i see projects as this i am angry with myself because i never learned to program microcontrolers

What's stopping you from starting now?

[gef12]

HI BW
Just keen for this to happen. Hats off to you BW. Am also angry at meself for not getting into programming Something like this should inspire us all.
So will sit back patiently and wait for it to blossom.
cheers
gef in OZ

[Geo]

What's stopping you from starting now?

Hi Qiaozhi. I am 47 years old, i have 3children (boys...the first is only 9 years old), and i make 2 jobs for a good sallary. At free time it is better (for me) to construct any detector or to drink whisky or wine. I started to learn how to program the PIC but i never finished it . What to do ... the years are years .....

[Qiaozhi]

Hi Qiaozhi. I am 47 years old, i have 3children (boys...the first is only 9 years old), and i make 2 jobs for a good sallary. At free time it is better (for me) to construct any detector or to drink whisky or wine. I started to learn how to program the PIC but i never finished it . What to do ... the years are years .....

It's never too late to learn.
The "two jobs" thing might be a problem though.

[bugwhiskers]

Hi guys,

When I started this project I was very focused and things progressed. A little while after this I had a rush of blood to the head and figured out an easy way to really capture what is happening in the decay curve. I am comitted to finishing this project but I am at loggerheads with the new idea as it has so much potential. Bbsailor and myself have had a lot of dialogue and he has been a real inspiration and help. I live in an area of Australia that has no shortage of gold to be discovered, as I speak there is talk of a specimen of gold with quartz being found very near where I live that is around 1000 oz of gold, the largest ever found with a metal detector.
I have been out with commercial detectors and a bucket full of axe heads, horse shoes, bullets, shoe tacks etc etc was the result.
I guess, what I am is asking is... do you want me to proceed with this project to it's conclusion, or do you want me to disclose the idea that has real potential and publish the circuit ?

regards
bugwhiskers

[Ray-NM]

I for one would like to know what your idea is, I have looked at the decay curve for iron and have wondered a few things myself.
Which ever you decide -go for it.
RayNM