PI CHIP

[moodz]

Hi Moodz, any chance I can purchase one of the micro's programmed with the latest software from you, Or grab one to test with please.

My location is on the mighty murray in vic.

I'll wait for a reply and if it is a go i'll pm the details thanks.


Cheers from Mick

PM your postal address and I'll drop one in the mail by end of week.
moodz.

[moodz]

Rotary encoder and LCD spec docs.

....these are pretty much industry standard types but here are the ones I used with the UNIPI chip. ( got them from Farnell or Element14 as they are called now in OZ ).

moodz.

powertip16x2LCD.pdf
rotaryQEIbournes.pdf

[mickstv]

PM your postal address and I'll drop one in the mail by end of week.
moodz.

Hi moodz, thanks PM sent. In the mean time i'll order a display and finish up the frontend electronics.




Mick

[moodz]

Hi moodz, thanks PM sent. In the mean time i'll order a display and finish up the frontend electronics.




Mick

You cando everything from the serial port if you can't wait to hook up the LCD

[mickstv]

Thanks for the info moodz.


I think it will take about a week to finish up the frontend so everything should tie in ok. Then off to Rushworth to do some testing as this is the closest location for the golden stuff. Although Bendigo isn't much futher. But Rushworth is a good place to start because the ground is really noisy, ideal for testing.


Mick

[moodz]

a "surf pi" front end for the UNIPI

The UNIPI chip is not just for differential front ends .... here is a simple cut down "surf pi" front end .....

there are only 4 connections required from the front end to the UNIPI chip.

TX
Sample 1
Sample 2
ADC in.

For audio out just use a 1k resistor in series with 16 ohm headphones .... you will hear clicking like gieger counter with no target. Freq will increase with target.

moodz

[WM6]

Superb! Thank you.

[moodz]

Superb! Thank you.

Thanks WM ....this is for illustrative purposes ... the circuit has not been tested ....however this is a development forum after all
Moodz

[mickstv]

Thanks moodz, That's pretty much what I was making my front end around. Once I get the chip and the rest is done i'll post some pix of the finished product.


Mick

[moodz]

UNIPI audio

A very simple audio output can be had from the UNIPI chip with simply a series resistor of say 1000 ohms and a 16 ohm headset. Just connect directly to AUDIO out pin of UNIPI chip.

Attached is an MP3 recording of audio output ..... clicking with no target .... frequency increases with target response..

Enjoy.

Moodz

moodzpi_audio.zip

PS ... the production line chip burner had a burnout so everyone who requested samples .... should be in the post Monday ... was Friday.

[mickstv]

Hi moodz, thanks for the update mate.



cheers
Mick

[mickstv]

Hi moodz, that package turned up today, thanks. The LCD and a few other components should come in on Mon or Tues, then I'll start final assy. The first version will be designed arround a MLab 10inch DD and Mono coils.


Cheers

Mick

[moodz]

active damping with servo tracking.

The real fun begins with the addition of active damping to the differential front end ..... the coil damping can be set from the menu now. No longer dependant on a fixed resistance the optimal damping can be dialled up from the rotary control. ( I am tired of gassing myself with burning resistors in the workshop anyway )

The servo tracking means that the damping can be autmatically adjusted on the fly as the coil inductance changes with changing ground conditions keeping the damping at some value.
I am still testing this ....it is currently so good that the front end gain of the first amp can be run at 1000 and with a small coin giving over 1 volt of output signal. ( dont forget that the back end can resolve 40 microvolts ) So coupled with the backend and a big coil will still be sensitive to big targets.

I will be testing the code some more before any releases ... also I need to determine exactly what active damping will mean since I dont have a commercial machine to to compare against.

I will also be looking to craft the algorithm so no matter what coil you hang off the machine it will "autodamp" .... no more resistor twiddling.

moodz.

[WM6]

I will also be looking to craft the algorithm so no matter what coil you hang off the machine it will "autodamp" .... no more resistor twiddling.

moodz.

Good news. Still not clear to me, if this "autodamp" is functioning literally as "auto", or we have some possibilities to control it at some degree from outside and adapt to certain soil situation?

[moodz]

Good news. Still not clear to me, if this "autodamp" is functioning literally as "auto", or we have some possibilities to control it at some degree from outside and adapt to certain soil situation?

Ok I will put auto and manual in the menu .... . The auto is not perfected yet so it is manual anyway however surprisingly it is much smoother and less noiser than variable resistor solution.
moodz