dspic30f4011 4 sample pulses

[moodz]

..this is the 40 pin DIP chip.

..has the extra hardware for the 2 additional sample pulse outputs.

..I made this to try out the Goldscan sample scheme .. Let me know if there is any interest

This is for the dspic30F4011 chip NOT the 30F4012

hex file and pic of serial port session talking to chip

... could ( probably has bugs ) .. try if you want ...

Metal23.zip

I already published the schematic for the 40 pin dip chip 30F4011 in the UNIPI chip thread ....

[6666]

I made this to try out the Goldscan sample scheme ..

Hi Moodz where would we find this sample sch please ?
Do you mean the Goldscan 1V ?

burner is in the mail


4011 here
http://www.geotech1.com/forums/showt...t=17795&page=4

at the moment you can get Four 4011 for Aud$20 on fleabay

http://www.ebay.com.au/itm/dsPIC30F4...item2a1013d8ee

[moodz]

Goldscan schematic.

.... can you see where the 4 sample pulses are use ?

Of course this is no drop in replacment ... IMHO the Goldscan front end is fairly primitive .... what might be interesting is if this two channel scheme can actually discriminate.

http://www.geotech1.com/forums/showp...03&postcount=4

moodz.

[ApBerg]

.... can you see where the 4 sample pulses are use ?

Of course this is no drop in replacment ... IMHO the Goldscan front end is fairly primitive .... what might be interesting is if this two channel scheme can actually discriminate.

http://www.geotech1.com/forums/showp...03&postcount=4

moodz.

Hello Moodz,

Thanks for the info !! Can be a very nice project ... !

Best regards.

Ap

[ApBerg]

Hi Moodz where would we find this sample sch please ?
Do you mean the Goldscan 1V ?

burner is in the mail


4011 here
http://www.geotech1.com/forums/showt...t=17795&page=4

at the moment you can get Four 4011 for Aud$20 on fleabay

http://www.ebay.com.au/itm/dsPIC30F4...item2a1013d8ee

Thanks for the link....

Ap

[moodz]

Hello Moodz,

Thanks for the info !! Can be a very nice project ... !

Best regards.

Ap

Thanks Ap ... I will probably only go as far as the coding of the chip for the 4 sample scheme ...if you want to try it I can make changes to code as you require....

moodz

[ApBerg]

Hello Moodz,

Thanks for the replay ! It made me start thinking ( pfff )
In the past I made a pcb-drawing for a 2 channel detector . This was all with “normal parts” . That I never made in real was because I like to make the timings for that 2 channel easy adjustable… so there can be adjustments for al coil size’s and soil…and iron disc.( sometimes I make pcb’s the way people make Sudoku puzzles.. at the end there is only a new start..)
Now you make some very nice Microchip programs for IC that can do a great job and adjustments can be made without a solder iron.. This made me motivated to start all over again to make a Iron disc PI detector. First thinking ; the ‘brain’ is your 2 channel 30f4011 , first amp Carls fast Ne5534 opamp design, transmit baracuda fet design, switching 4066 or fets ? (like fets … make pcb design easier) diff.opamp and following as usual.. audio vco? And led / meter out for iron indication.. etc.. No smd, so can be made easy…

Thanks again ! Like to know what you think about it...

Best regards

Ap


The 2 channel that never made it in real....

[ApBerg]

Hello Moodz

Perhaps use Carls HH2 design?? only add a second cannel for (large) iron detection?
From the HH are nice doc's , how it works is good explained...

Best regards.

Ap

[moodz]

Hello Moodz

Perhaps use Carls HH2 design?? only add a second cannel for (large) iron detection?
From the HH are nice doc's , how it works is good explained...

Best regards.

Ap

You are right Ap ...Carls hh is the best documented. How close was you design to the hh?
Cheers,
Moodz.

[6666]

Hi Ap would you mind showing us the schematic of your 2 channel design please ?
cheers
6666

[ApBerg]

Hello Friends,

The pcb is much Surf copy... so it looks also much as Carls HH, the signal processing (if I can call it that way) is somewhat different.

I find it no problem sharing the circuit schematics, but than by a P-mail, there can be errors in those schematics and boards so it is not wize to place this on the Forum... I have not made or tetsed things in real live...! 6666/Moodz, I send them to you but it can take some day's.

Best regards.

Ap

[moscadondres]

Hi Moodz,
The crystal on the 30F4011 is:4Mhz or 40Mhz;regards.

[moodz]

Hi Moodz,
The crystal on the 30F4011 is:4Mhz or 40Mhz;regards.

Hi mo ... you dont need the crystal for the current code version ... it uses the internal oscillator on the chip .... however a future version will use 7.37 Mhz.

cheers.

moodz.

[6666]

7.37 Mhz is a bit of an odd freq, where do you get one of those ?

[moodz]

7.37 Mhz is a bit of an odd freq, where do you get one of those ?

Yes thats what I thought but Microchip specified it for a whole range of their chips and you can get them very cheaply from the big supply houses. Actually I got some of these crystals cheaper than the "normal" frequency ones. ( 33 cents each )

The reason for this frequency is this ... the crystal oscillator is multiplied by 16 internally. The "official maximum" internal clock is 120 Mhz on the dspic ( you can overclock though ). Each instruction takes 4 clocks thus you arrive at 120 / 4 = 30 MIPs they specify for the dspic.

For my code I use the internal RC clock at 7.37 Mhz and the same result is obtained ... 30 MIPs .... there is some jitter on the clock but it is better than 33 ns .... is 33 ns of jitter critical in a PI operating at sample resolution of 1 microsecond ? ( 1000 ns )

I would say no as the timing of the PI is critical from pulse to pulse and with all the averaging that occurs after demodulation you could not pick 33 ns of jitter. If I was building a clock for time keeping it would be a different matter of course.

So its a matter of long term accuracy ( frequency ) vs short term accuracy ( jitter ) and the long term accuracy is not a real factor in the code at this point in time.

The bottom line is that at the moment no crystal is required for the UNIPI V230 code.

moodz