HH3 premises

[Helikeon]

A further thought - USB connectivity would be another nice feature.
This would be useful to allow for ...
1/. Software modification.
2/. Save and load different user settings.

[bbsailor]

A Few More Ideas To Consider

I would like to continue in the Geotech tradition of brainstorming the HH3 design with the active members so that a full range if ideas are explored.

1. If a minimum delay is desired, mount the control box on the shaft to keep the coil lead as short as possible as well as allow some additional features noted below. Batteries and headphone connection can be body mounted to reduce the weight being carried.

2. Consider adding the ability for the control box to sense the ends of a swing with a small accelerometer mounted in the control box which will allow for the following.
A. Once a target is located, switch to the ID mode by the press of a button. This will activate the increasing or decreasing of the main delay and/or pulse width with each short swing over the target by an amount selected by the user based on the hunting location and type of targets sought. By listening to the strength of the target signal with each sweep and resulting delay and/or pulse width change, additional information about the potential nature of the target's identity can be deduced.
B. In the general hunting mode have the user input their normal hunting sweep length and then have the accelerometer sense the speed of each swing and alert the user with a beep or light that the coil is being swept too fast for the timings selected.

3. Another useful technique to extract additional information from an unknown target is to do a slow sweep over a target and then increase the sweep speed. If the signal strength increases with a change in sweep speed it is most likely a ferrous target.

4. By using a MOSFET to replace the damping resistor, the effective resistive value of the MOSFET can be controlled by software to optimise the response from the coil to various pulse widths which cause a variable amplitude in flyback voltage. When seeking targets with the shortest time constant you want to sample at the earliest possible time. Adding a variable damping capability allows the coil to be dynamically damped, always ensuring an optimal target response based on the pulse width and exhibit the shortest possible delay.

5. The PI probe is a very good option to consider when either beach hunting of seeking small gold nuggets. This probe can be added to just about any PI design by simply switching out the coil and switching in the probe with a simple SPDT switch. The probe can be wound with a higher inductance than the search coil on a soft ferrite core to make it very sensitive for locating small close targets.

A beach hunting PI machine will have different coil, pulse and delay characteristics than a small gold nugget seeking design but there will be some overlaping characteristics.

These are just some ideas to consider and can be implemented individually or in combination to push the pulse induction technology into the next generation (PING).

In design, the next logical step is to rank the desired features/requirements and then decompose each desired feature/requirement into specific technical requirements.

Comments please.

bbsailor

[ivconic]

Nicely elaborated. Agree.

[ivconic]

My preferred premise is to continue HH3 as a learning platform, not really as a cutting-edge design. But it should have very useful performance.

Anyway, here are some thoughts.

• I personally prefer PIC chips. They are plenty good enough and have outstanding support amongst experimenters. Lots of books, too. Might have to go with a 24F or dsPIC.
• Support for mono & IB loops.
• Probably go with a character display for cost & ease. HH1 & HH2 have no display, so this is a first good step. HH4 can have graphical!
• Support GB and multi-point sampling.
• Mixed analog/digital, with most processing moved to digital. HH2 has an option for direct sampling the preamp, so this is a good first step in testing ADC resolution and processing algorithms. HH3 may require a better external ADC. A decent 16-18 bit ADC with 1-2us sampling rate can be pricey and hard to obtain in some places, so I need to be careful.

- Carl

This pushed me to think about 24f series a bit more. Maybe is time me to "upgrade" my programming hardware. I stuck to PropicII for longer period.
So i searched internet looking for some easy and free programmer. Epic or simillar... I need schematic and will make my own device. I could'nt find anything more usefull...
Yet there is local manufacturer offering this:
http://www.mikroe.com/en/ (LV 24-33 model) actually out of stock, but there is newer available model: http://www.mikroe.com/en/tools/lv24-33a/


Good choice for professionals and developers. But i am neither of those.
Anybody have a schematic of some simplified programmer for 24f series?

[Qiaozhi]

This pushed me to think about 24f series a bit more. Maybe is time me to "upgrade" my programming hardware. I stuck to PropicII for longer period.
So i searched internet looking for some easy and free programmer. Epic or simillar... I need schematic and will make my own device. I could'nt find anything more usefull...
Yet there is local manufacturer offering this:
http://www.mikroe.com/en/ (LV 24-33 model) actually out of stock, but there is newer available model: http://www.mikroe.com/en/tools/lv24-33a/


Good choice for professionals and developers. But i am neither of those.
Anybody have a schematic of some simplified programmer for 24f series?

I have the EasyPIC 5 ->
http://images.google.co.uk/imgres?im...a%3DG%26um%3D1

... and now I see they've brought out EasyPIC 6.

[Helikeon]

Anybody have a schematic of some simplified programmer for 24f series?

The information at http://www.edaboard.com/ftopic263523.html might be useful.

You will need to register (free) in order to view the attachments though.

[ivconic]

Thanks, i just saw it.

[Helikeon]

Hello Ivconic,

Here is some additional information for a Pic programmer apparently suitable for 24 and 33 series Pics - perhaps you have seen it?

A "Wiki" at http://www.icd2clone.com/wiki/Main_Page

and the original thread at EDA board http://www.edaboard.com/ftopic161641.html

[ivconic]

Thanks Helikeon!

[mts]

Anybody have a schematic of some simplified programmer for 24f series?

I'm new to PIC's (I'm an old school 8051 guy). But what's wrong with the PICKit2 as a programmer? I haven't programmed any 24f series with it yet but it says they are supported. And I understand that it is a hobby device and not intended for large scale development. I'm just trying to get a feel for what everyone else is using. Coming from the old 8031 world where you had to have an external EPROM, the PIC series of microcontrollers and the cheap PICKit2 is a dream come true.

[Carl-NC]

Nothing wrong with it AFAIK... I have a PicKit3 and it works fine. I think it's just an upgrade to handle the new J & K series parts.

[matabele]

My 2c

The major problem facing DIY electronics projects around the world is procurement of new and exotic (expensive) components. A design such as HH should use easily available standard components wherever possible with high spec. components only where absolutely necessary. A design like the SMW is popular because it uses only a few standard components. The move to a uC design will assist in this respect.

I also suggest a modular board design:
- uC
- power supply
- transmitter
- receiver pre-amp
- signal processing (if analogue)
- output audio/graphic

In this respect - have a look at the Pinguino project. This is a PIC based uC board that can be made for under $10, with an easy to understand arduino like language, which can interface to a PC in real time via usb.

Perhaps we should begin by determining an available parts list?

[goldfinder]

Signal processing and PIC and HH3/4

Great Idea to use the PIC and do some DSP.

For myself I'd prefer
0. Open source
1. a single board with power supply
2. one of the PICs
3. a decent A2D converter that can easily interface w/ whatever PIC is chosen
4. interface w/ a LCD display.
5. Buttons and pots to control in beginning, later maybe something more sophisticated.
6. Analog to drive coil, PIC and A2D to read return signal. PIC to process the signal, then display results.

The KISS principal should be paramount. Ending up w/ needing a phd to run the thing in the field is not productive.

I tried some of this but not good enough w/ the analog to interface with return signals from the coil and didn't use a good A2D. Assume this is a PI machine.

I use the Microchip PICstart development board and their MicroLab free development environment. It is always up to date and the free development lab is superb.

I've done a bit of DSP over the years, had a consulting co doing it so at least have a little background that can help.

This seems to be dead thread - is anyone interested in this. I for one think it is a great way to go.

Goldfinder

[Tinkerer]

Great Idea to use the PIC and do some DSP.

For myself I'd prefer
0. Open source
1. a single board with power supply
2. one of the PICs
3. a decent A2D converter that can easily interface w/ whatever PIC is chosen
4. interface w/ a LCD display.
5. Buttons and pots to control in beginning, later maybe something more sophisticated.
6. Analog to drive coil, PIC and A2D to read return signal. PIC to process the signal, then display results.

The KISS principal should be paramount. Ending up w/ needing a phd to run the thing in the field is not productive.

I tried some of this but not good enough w/ the analog to interface with return signals from the coil and didn't use a good A2D. Assume this is a PI machine.

I use the Microchip PICstart development board and their MicroLab free development environment. It is always up to date and the free development lab is superb.

I've done a bit of DSP over the years, had a consulting co doing it so at least have a little background that can help.

This seems to be dead thread - is anyone interested in this. I for one think it is a great way to go.

Goldfinder

Hi Goldfinder,

I would be interested to work on this project. Attached is a PSU&TX board that I am getting ready to etch. Do you have any suggestions for improvements?

Tinkerer

[goldfinder]

Hi Goldfinder,

I would be interested to work on this project. Attached is a PSU&TX board that I am getting ready to etch. Do you have any suggestions for improvements?

Tinkerer

Tinkerer,
I couldn't get a version of this picture with any clarity to read it. You need to post a better picture.
Goldfinder