Tesla App Based Detector?

[Steve Herschbach]

Bad Google translation at https://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&nv=1&prev=_t&rurl=translate.google.com&sl=auto&tl=en&u=http://www.tousapoele.fr/xp-deus-v4-et-nouveaux-accessoires/

[Steve Herschbach]

Looking more into the Go Detect app it may not end up being an operational interface for the DEUS but simply a mapping system. I went ahead and started another thread on it at http://www.detectorprospector.com/forum/topic/1436-xp-metal-detectors-go-detect-app-for-smartphones/ to keep a separate eye on it.

[jasong]

Man oh man, this is a concept that I was pounding my fist on Nuggetshooter forum when I bought the first Motorola Droid, the first day I had it all I could think is "this is the future of metal detectors", and it fell on completely deaf ears, back in 2009 or so. Fewer people owned smartphones then though, the concept seems even more doable now.

You needn't have everything in the coil even, there is no reason you couldn't have a "dumb" box mounted on the shaft still or inside the shaft for that matter. The main thing is analog circuitry, you need the battery, oscillator and amp (actually, just the amp really) maybe a few analog filters. The DSP capabilites of a generic smart phone is lightyears ahead of what would be required for a normal detector, you could do so much digitally that is now taking space and weight up physically. Imagine if physical detectors (the shell) were sold by many companies as one unit, and the digital component (the brain) in the form of an app were sold by other companies as another unit, and you could mix and match and combine as desired to make different machines...?

Also, depth isn't just a problem of mag fields decaying as 1/x^3. Decay may be exponential, but it still decays off to infinity and off in infinity is still a detectable signal, just diminishingly small. So in theory, if you can lower the noise floor enough then you can "hear" a signal from quite far away. Even in some cases when the signal is below the noise floor. Galaxies away with radio telescopes, granted we don't have an array of coils so no direct comparison (hmm...why not though?). So you can brute force depth by throwing more power at it, or you finesse depth by making a very sensitive "ear" and using very complex digital filtering to reduce noise so that the weak signal remains. Such things should be possible now that we have companies who are actually using modern technology instead of trying to crowbar old news into something resembling a modern paper.

Conceptually speaking at least. In practice always much harder of course. But it's fun to think about.

[Clay Diggins]

On December 10, 2015 at 1:36 PM, Steve Herschbach said:

Bad Google translation at https://translate.google.com/translate?act=url&depth=2&hl=en&ie=UTF8&nv=1&prev=_t&rurl=translate.google.com&sl=auto&tl=en&u=http://www.tousapoele.fr/xp-deus-v4-et-nouveaux-accessoires/

That's a remote control Steve. It's been done. Could easily be done with a phone, probably even an old dial type if you can live without the display. Even the ad refers to it as a novelty accessory.

I thought you were talking about signal processing a transmitted coil signal on a phone. That's what a metal detector does (like I need to tell you that. ).

An App Based Detector. That's what I was addressing in my post.

It's not all about processor speed despite the hype. No way does an iPad have the processing power of a modern desktop computer. It doesn't even have a decent I/O interface much less the processor or bus speeds.

Neither the AMD phone chips nor the Android operating system have double precision floating point processing capability. Trying to crunch numbers on a pad is like molasses in January compared to a modern desktop. Crunching numbers is an important tool in my business and we have tried on our iPad.

The phones and pads are good at what they are designed for but so is the cheapest Bounty Hunter. Depends on what you want to accomplish it's not about the frequencies mentioned in the advertising. If you just want remote control from your phone that is very doable.

[jasong]

No, Android can handle 64 bit numbers, and there are already 64 bit smartphones (more next year). Android is a full fledged Linux based OS like any on your computer and modern smartphones CPU's are definitely just as powerful as the laptop I am typing on now.

It doesn't really matter anyways, most sensors are 8, 16, and 32 bit. Most built for MCU's like aftermarket magnetometers and accelerometers are 16 bit still, and 32 bit for something like a coil or antenna provides plenty of resolution, more than you'd need for a metal detector I'd guess.

You can make a professional PI or VLF with a 16 bit MCU running under 25mhz. A 32 bit quadcore phone running 1.2ghz is much more than powerful enough, add on a standalone DSP chip and a frontend analog filter and you have miles of open processing power to use.

Not to mention you can now buy a full fledged 64-bit dev board with MCU and operating system installed for $15, with multiple SPI and I2C busses open even after you add in the HDMI and USB ports. Dunno what the ADC is though it might still be 32 bit, I don't see a real need for 64 bit precision with a metal detector anyways. $15. Kinda shows how incredibly cheap the modern detectors are and how much markup we are paying for them...and also why it's just easier to replace and entire machine rather than pay a repair person to fix it. I'd be honestly surprised if the GPZ costs more than $200-$300 to produce for instance, there isn't any pixie dust inside, it's a piece of plastic and electronics just like anything today.

*Also, check this chip out, coming to a phone near you! That'll make my desktop computer look like a fossil.

**Also also, you can still do double floating point format in Java (as with other languages) just by declaring type double, even on 32 bit processors and I believe it stores the number in memory as two 32 bit binary numbers. But again, it's not really necessary.

[Clay Diggins]

I'll look forward to your new super detector Jasong!

[Steve Herschbach]

Well I think we can all agree that the speed with which processing power and storage capacity has been progressing is nothing short of astounding. It seems just yesterday I obsessed over drive space and eking out a few more k of ram. Now terabyte drives are the norm. I gave up trying to keep up with it all anymore things are moving so fast. Fun times to be a geek!