Universal PI Micro

[bugwhiskers]

Addendum

The diodes in the feedback path of the pre-amp need to be reversed. Also, the diode marked "germanium" can be a schottky 1N5817 or similar.
The resistor between the MOSFET driver and the IRF740 can be deleted, it causes ringing.

regards
bugwhiskers

[Unregistered]

Hi BW
Is that all diodes in feedback path or just the D9 and D7 ??
I follow this projecto of yours with good interest.
I hopes it sucsessful
Henry in Bulgaria

[bugwhiskers]

The quick answer is all the diodes in the feedpack path. In a few days I will post a revised schematic with those changes and a few others.

regards
bugwhiskers

[bugwhiskers]

Revision

The attached .sch & .brd have a few revisions. The feedback diodes are now shown with correct orientation. Support has been added by way of headers for dual coils, either double "D" or seperate RX/TX coplanar types.
C20 & C1 should ideally be a low ESD type. D1 & D2 have also been changed for more readily available types.
The IRF740 is shown laying on the board and fouling C1 whereas it is actually mounted vertically.

regards
bugwhiskers

[sharky]

Hi

Hi any thing new on this Universal Micros, lots of Flash Ram and big screens, just 4Kb flash is more than enough for this application...u need to concentrate on 1st stage of the opamp....rather than the screen and 24 bit adc...wonder where u r clocking the micro @4Mhz !! this will be too low clock....does Any body has a better schematic with source code for a sensitive PI..

[bugwhiskers]

Hi Sharky,

Where did you get the idea that the Evaluation board is running at 4MHz ? It's running at the full speed of 12 MHz.

The current screen is a common 2 line LCD display that is used to show signal strength and also allow the user to alter timings.

What do you consider is wrong with the latest published tried and proven pre-amp ?

regards
bugwhiskers

[sharky]

nice can i have the source code in c and also the full schematic link please, please please...I think u have got enough finds in austarlia if I remember if u r from australia, if u have enough of this finds why dont u come to India with ur working detectors we can show u lots of treasures in kgs and tonns, some visible in caves but u cant go and touch them, there r others buried but suitable for ur detector

[bugwhiskers]

Hi sharky,
The schematics & PCB have been posted in .PDF format previously, in a couple of days I will post the Eagle files zipped.

The source code is written in assembler.

regards
bugwhiskers

[sharky]

Dear Bug Whisker
I am familiar with C, for modification I need c source code, I need .schema file extension so that I can do some modifications in circuit

[Bill]

I am familiar with C, for modification I need c source code, I need .schema file extension so that I can do some modifications in circuit

Why don't you have him wash your car while you are at it.

[sharky]

Dear Bug Whisker
Can I have the latest project link, whats the depth in air for a coin and small 2 cm square iron....

regards

[bugwhiskers]

Unavoidable delays

I haven't posted for a while due to paying work commitments and experimentation with a method of eliminating the ground signal at the front door as well as a method of annihalating the back EMF to enable very early sampling.

regards
bugwhiskers

[sharky]

Seperate the power supplies and use opto iso to sample early

[bugwhiskers]

Board & Schematic zipped

The attached .zip is the schematic and the board in Eagle format. See previous posts for the link to download the free version of "Eagle Light".

The board is single sided with only a minimal number of links and is very easy to make at home with the right equipment.


regards
bugwhiskers

[sharky]

Bug Whisker

The attached .zip is the schematic and the board in Eagle format. See previous posts for the link to download the free version of "Eagle Light".

The board is single sided with only a minimal number of links and is very easy to make at home with the right equipment.


regards
bugwhiskers

Dear Bug Whisker

I have eagle, orcad, cadstar too... all full versions...even spice simulator Electronics workbench NI MultiSim too