Update on Basic stamp and Hammerhead

[Ray-NM]

Basic stamp

This last weekend I hooked up the basic stamp to a breadboard of the clock circuit from the Hammerhead with Q1 Q2 with associated components and Q3 with coil diodes and 1k resistor. I used the BS to pulse the circuit and try out different coil and cable combinations.
Minimum pulse width was 2 usec and I adjusted it up to about 200usecs.
Just wanted to get a look at the readings on each component.
Well I found that my circuit Produced a delay of about 17 usec no matter what coil or cable combo I used. I figured there was no way all of them produced the same delays. So I started looking at the signals starting at the input to Q1 and on til I got to the gate of Q3.
I found that at the base of Q2 I had a problem in the fall time of the circuit.
From pulse turn off till 0 volts or -Vbb it took about 10 usecs to reach 0.
Way to slow to trigger the gate of Q3 into cutoff which is about 4 volts.
After changing the value of the resistors I was able to get virtualy no delay from the pulse turn off from the bs to the gate of Q3 which gave me a 7 usec delay rather than the 17 usec delay I had when I started.
So you see the BS is a useful tool in learning how to optimize the circuit using a breadboard for different subsections. programming is precise, if you want to change the pulse width or Freq it is just a matter of changing a couple of numbers and clicking run and you have it. This way the settings are always the same. Now I have to go back to the Hammerhead board and find out where I may have a wrong component value or possibly a bad one.
More to come
RayNM

[wyndham]

This is very interesting information on the MP.
I ran across an ad for the Parallax Propeller education kit (#32305) for $79.95 that has a breadboard and chip & circuit components that also maybe of interest to some here. Parallax has several files in both pdf and zip that show the operations of this chip and the language, spin(I think). Maybe a hybrid of c or basic or assembly.
It might be worth checking on. It has a USB port and easy to download a compiled program it states
Hope this keeps going as I am interested but a long learning curve for me.
Thanks Wyndham

Propellar chip specs Power req 500uA/[email protected] vdc Ex clk speed- DC to80 MHz(4MHz-8MHz w/PLL running) internal RC Osc 12 Mhz or 20 khz- Sys clk sp DC to 80 MHz COGS 8 preformance 20 MIPS/ cog @ 80 MHzglobal ram/rom- 32 KB ram/ 32 kb rom-processor ram 512x32 per cog- I/O ports 32 -- current source/sink per I/O 30 mA

[bugwhiskers]

Dedicated experimental PIMD micro.

The attached .pdf shows a preliminary detailed overview of a stand alone circuit board that will greatly aid those conducting experiments in PI metal detection. It can drive PI's like the Hammerhead, Gary's PI, Goldscan4 etc.

There are 3 outputs to drive analogue switches or JFET's, most PI's only use 2. The delay between each output and the sample width are adjustable from 0.5uS to 512uS and are displayed simultaneously on a 16 character * 2 line screen. The screen will have another page to show a digital readout and bar graph of the final stage signal strength.

Two pots and a pushbutton serve to navigate around the adjustments and displays. Turning the "mode" pot will cause stepping between various screen pages and variables. The "adjust" pot causes the variable to be changed with the "accept" button storing the new value. Adjustments will be live, so the user has instant feedback. There will be provision for storing (retained with power off) 16 sets of all variables into EEPROM.

Feedback and suggestions for additions are very welcome and the sooner the better as I am in the process of laying out the board.

To complicate things, I have finally bitten the bullet and started to learn to use "Eagle" light PCB program after using a DOS version of PROTEL since 1990.

regards
bugwhiskers

[gef12]

Possiblities

Hi
Am a prospector / tech in Australia.
I prospect mainly for gold and would be interested in a machine that would find nuggets in highly mineralised ground. Have built the HH opt 2 and seems to be working fine allbeit with some slight mods.
So would be interested if this unit u are engineering would incorporate Ground balance for difficult ground.
Just some thoughts
gef

[bugwhiskers]

Hi gef12,

I live in Ballarat, and I know exactly what you mean by wanting to find gold amidst highly mineralised ground.

The UPIM is not a metal detector in it's own right but a very stable, accurate and most importantly configurable device for driving the analogue section of a PI metal detector.

bbsailor has sent me a lot of info on ground balancing that we hope to incorporate into to a Hammerhead driven by the UPIM, "McHammerhead" (Mc = Micro controlled).

The ability to discriminate at depth would also be very desireable and the more information that can be gleaned from the target will help enable that.

regards
bugwhiskers

[Ray-NM]

Thanks for the schematic.

I printed it out and will look it over this week. I was wondering how fast the opto couplers were. Thanks for the info.
RayNM

[Ray-NM]

This is very interesting information on the MP.
I ran across an ad for the Parallax Propeller education kit (#32305) for $79.95 that has a breadboard and chip & circuit components that also maybe of interest to some here. Parallax has several files in both pdf and zip that show the operations of this chip and the language, spin(I think). Maybe a hybrid of c or basic or assembly.
It might be worth checking on. It has a USB port and easy to download a compiled program it states
Hope this keeps going as I am interested but a long learning curve for me.
Thanks Wyndham

Propellar chip specs Power req 500uA/[email protected] vdc Ex clk speed- DC to80 MHz(4MHz-8MHz w/PLL running) internal RC Osc 12 Mhz or 20 khz- Sys clk sp DC to 80 MHz COGS 8 preformance 20 MIPS/ cog @ 80 MHzglobal ram/rom- 32 KB ram/ 32 kb rom-processor ram 512x32 per cog- I/O ports 32 -- current source/sink per I/O 30 mA

I mainly purchased the Basic stamp 2 because it was at Radio Shack and the price was the same . Like I said before it should allow me to test differnet configurations of coils and mosfets to get the best out of the Hammerhead.
As it is I found I have a problem on the main board so once I get that figured out I can go on to other areas of the circuit and optimize them.
I will probably upgrade to the Propeller chip later as it seems to be the most
Versatile and easily programable.
I would venture to guess that Carl is coming up with something similar for the next version of the Hammerhead.
RayNM

[wyndham]

It was just a coincidence that I had a copy of Nuts & Volts w/ the Parralax ad on the back cover. I also found a fellow who wites articles in that mag that has a pic chip w compiled basic, (the Atom) with several pkgs that look interesting www.elproducts.com his basic is between interpeter and compiled but there is a compiled version from micropic?? Any way since I have just started reading about these different PIC's I'm behind where most here have already gone.
BTW I used to work for a fellow named Ray Nanco in Grants NM(1976-77) , it would be an interesting coincedence if you knew him or any relation. He was an avid prospector and suveyor at the mines there,at that time.
Wyndham

[Ray-NM]

I dont recall ever meeting him. But Grants is about 70 Miles away from Albuquerque. There are a lot of us prospectors here in nm we just keep quiet about it. this state has some of the toughest regs on mining. Just about have to get a permit to get a permit. yes I am learning also about using Microprocessors in detectors. I think it is the best way to go to get a detector that is sensitive and has some real depth for gold.
Coins and iron are easy.
RayNM

[bugwhiskers]

I printed it out and will look it over this week. I was wondering how fast the opto couplers were. Thanks for the info.
RayNM

Hi Ray-NM,

NEC make a range of opto's with switching speeds from 5 uS(PS8103) to 40 nS(PS9661).


regards
bugwhiskers