Electronics Nerds and Copying a Detectors Control Box

[JeffP]

Do you reckon it would be possible for an electronics nerd to look inside one of the popular Detectors of today and be able to copy it ?
Because I am sure it would cost stuff all to build one ,,,, we are paying for the research and development of said Popular detector
And , NO , I am not thinking to sell them , but just be able to make one for your own personal use .

 

[AtomRat]

Most of the circuit can easily be copied but you would need to deassemble the code on the microchips and this can be impossible at times. You will be able to get something close to the detector you copy, but unless you can get the code, you will have to program your own IC 's to suit the board, another hard task to attempt.

You are better off learning electronics and programming a PIC or Ardiuno board, attempting to make your own detector rather than trying to copy one.

Already there are many small detector kits that can be a great start like the Surf P.I or Velleman Metal Detector kits or any similar

 

[Kerro]

I think you would find that quite a substantial amount of the cost is in the hardware. Lithium batteries, charger, vacuum formed coil housings, custom enclosure etc etc. You are correct in that the electronics cost stuff all and I suspect depending on the brand of detector the code can be quite straight forward (forget ML).

I have actually replicated the functions of my Whites TDI Pro PIC code and then modded it to allow for 8us delay timing. Never touched the original code on the chip as it wasn't necessary (was able to keep a copy of this incase I had to restore the original). I simply probed the chip to see what it output, then made a small breadboard prototype with the exact same type of chip (this is literally just a chip with a few LEDs hanging off it, not a detector circuit). Took a little bit of buggering around as I had never actually programmed a PIC before but in a couple of days here and there I had a working chip. The hardest part was programming the chip in circuit. Fun fact: the original TDI Pro must have used an atmel chip as the program header is not right for a PIC. In any case some carefully placed alligator clips and socket headers did the trick.

So in the end is it possible? Yes. Is it worth it? Probably not. As AtomRat suggests you are better off making from scratch, or buying.

Forget copying though, it would be more interesting if a group of people got together and came up with a truly open source detector that anyone could build - without worrying about stepping on patents. Now that would be cool

 

[JeffP]

Wow , you guys sound like you might be the Nerds I'm looking for

 

[KarlS]

I don't think so. Most of manufactures use OTP micros and when they are programed they blow the links to the program access and can not be read. You can not disassemble program you can not access.
The PCB board would have to be copied exactly as different layout could introduce undesired noise and degrade performance.
Generally, it would be easier to design detector from the scratch then make successful copy of high end machine.
Karl

 

[blisters]

You might also find some electronic components do not have identifying marks. In that case you would have to understand the circuit intention to identify the unmarked component. If the circuit is driven by the chip then it becomes very difficult to determine the circuit function without the code. While what I have said may not be the situation with what you are copying it should demonstrate just how difficult it can get very quickly to reverse engineer. You would be better putting effort into understanding the theory and design rather than copying. If you measure a detectors coil transmit and receive over various targets and depths you'd get a good idea of the theory of operation together with the circuitry and supporting code that is required.
Jon

 

[AngerManagement]

I don't think so. Most of manufactures use OTP micros and when they are programed they blow the links to the program access and can not be read. You can not disassemble program you can not access.
The PCB board would have to be copied exactly as different layout could introduce undesired noise and degrade performance.

Generally, it would be easier to design detector from the scratch then make successful copy of high end machine.
Karl

Unless you had a big enough market to on sell the copies - not worth it to even consider it....

But understand the process and technical issues; can allow you to make modifications to some parts of some equipment.. Do it to a number of machines... Sometimes can be worthwhile, others it is not worth the cost or the time.

 

[SteelPat]

I have built quite a few PI detectors with varying degrees of success. If you want to build one just to save money then you are wasting your time. If you want to build one because you are interested in how detectors work and like experimenting, then go for it.

Most modern detectors have microprocessors that control all the timings etc. While its fairly easy to program, knowing the timings etc is the trick. Some of the older detectors have had their timings measured and are freely available on the web. The newer units tend to be closely guarded secrets.
Also some brands tend to cover their boards with an epoxy to 1: seal from weather 2: protect from prying eyes. Makes it trickier to reverse engineer.

If you want some technical info on detectors, message me and I can either send you circuits etc or point you to a tech site that has loads of info on it.

 

[DrDuck]

I don't know much about detectors, but am an amateur radio enthusiast, so have some knowledge of complex communication equipment. In addition to the points raised above (all valid), much modern electronics uses surface mount components and multi-layer boards. This makes reverse engineering all the more difficult, outside of having a dedicated laboratory it is a tough ask for a hobbyist. Then there is the issue of sourcing all the (sometimes obscure) parts, designing and making the boards, and assembly, all of which requires specialist resources and knowledge.

I think SteelPat gets it right.

 

[SteelPat]

While I am no expert on all things metal detecting, I am a tech with over 30 years experience and own my own electronics business that does warranty repair work on many major brand electronic products ie Plasma, LCD, Audio etc.

I myself originally thought that I could re-invent the wheel so to speak and save a few bucks. Having the workshop and all the equipment is certainly an advantage but I soon realised it was pointless. It was great to learn all the theory but I couldnt hope to build a detector to compete against the best gold machines.

In saying that, I have built a few detectors that would give many a current relic machine a run for its money... shame I prefer the yellow lol.