Legend Internals, Circuit Board, Processor, Etc.

[Cal_Cobra]

The headphones that come with the Legend are pretty nice.  Seem much beefier than the ML80's, although my ML80's are still going strong.  The audio is [to me] good.  Some people didn't like the audio on the ML80 headphones, but I felt it was just fine.  For the most part this is a very subjective matter, depends on your hearing. 

Could be when NM was designing the Legend that the Bluetooth 5.2 module wasn't available yet, or you could be right it could be a cost reduction move.  Still 5ms latency is impressive.

I felt the Legend headphones were comfortable. They've an "over the ear" design versus an "on the ear" design like the ML80's.  

[JCR]

I'm not familiar with the latency levels discussed. I know my current NM Green wireless headphones & my Garrett Z Lynk don't seem to have any noticeable lag. So the Legend is as good or better?

[phrunt]

Z-Lynk is 17ms so faster than atpX Low Latency, while I don't know Nokta's latency for the green headphones Wireless 2.4GHz is generally a 16ms latency.  Anyone that has used the Minelab ML-80 headphones will know how the Legend headphones will perform, the same latency is shared between the two.  I personally can't tell any lag at 40ms which the Legend will run at.

[Cal_Cobra]

23 minutes ago, JCR said:

I'm not familiar with the latency levels discussed. I know my current NM Green wireless headphones & my Garrett Z Lynk don't seem to have any noticeable lag. So the Legend is as good or better?

I didn't observe any lag on the Legend headphones.  Some folks claimed they noticed lag on the ML80's and EQX, but I never did.  Ive never used the Garretts, but I have the NM Green wireless headphones for my MMK, and I like the Legend headphones better.  I think they're a little better build quality, although the Green wireless headphones were just fine from my experience.  I'm glad to see NM going to an open standard wireless format 👍

[DIG5050]

Very Nice pics and tech details on the N-M Legend, phrunt.   Any guess as to whether there are more active devices in the coils, like M-L has in theirs?

[phrunt]

Thanks, I think there are, refer to this thread. 

To quote Dilek,

"To answer your question, we are open to collaborating with any third party as long as it makes sense for both parties.

Detech approached us for making coils for the Simplex and we welcomed it and worked together on their coils. 

Now, I know NEL announced coils for the Simplex+. However, they could not technically manufacture coils for the Simplex+ unless they bought certain parts from us. I personally sent them a message via the distributor and told them we were open to collaboration. Last thing I heard was they were going to get back to me with a proposal but they never did. I asked one last time and never got a response and I do not know the reason why... and this was back in January 2021. "

You'll note they need to buy certain parts from Nokta to make coils for it, what part could that possibly be, it has to be something electronic, it's not coil wire or plastic, could it be something as simple as a plug end? I don't think so.  She did also use a plural, parts so it's likely maybe a pcb and a plug end.

Either way, they're open to Aftermarket coils, so to me that's good news as long as the aftermarket coil manufacturers think it's viable, they obviously didn't for the Simplex but being such a cheap machine maybe it wasn't viable to sell a coil for near the price of the machine.

 

 

[DIG5050]

Yes. I'm thinking PCB, also.  Maybe we could talk Strick  into X-ray image a coil for us.   I would like to see whats inside an Apex coil, too.

[Geotech]

23 hours ago, Cal_Cobra said:

If it's that, it's not going to set the world on fire, but still that's more than enough compute power for a metal detector.  Could always leverage a DSP if needed if not already.

32b Cortex processors have plenty of horsepower for detectors. M4 cores (as apparently in the Legend) have a hardware multiply so they even have some DSP muscle. Almost all my designs use STM32 micros. The F-Pulse/TekPoint has an STM32L072, the walk-thru has an STM32L496, and another design has an STM32F767.

4 hours ago, phrunt said:

it's interesting they didn't go with Bluetooth 5.2 with the LC3 codec where the latency is as low as 5ms.

Have you seen anything with 5.2 LE audio? I think Qualcomm has a chip that supports it and I've seen one set of 5.2-LE earbuds, but nothing else. No off-the-shelf headphones or transmitters. The companies I'm watching in particular are ST-Micro and Nordic, because working with Qualcomm is a royal pain. We also tried Feasycom and found them to be very unresponsive.

[phrunt]

12 minutes ago, Geotech said:

32b Cortex processors have plenty of horsepower for detectors. M4 cores (as apparently in the Legend) have a hardware multiply so they even have some DSP muscle. Almost all my designs use STM32 micros. The F-Pulse/TekPoint has an STM32L072, the walk-thru has an STM32L496, and another design has an STM32F767.

Have you seen anything with 5.2 LE audio? I think Qualcomm has a chip that supports it and I've seen one set of 5.2-LE earbuds, but nothing else. No off-the-shelf headphones or transmitters. The companies I'm watching in particular are ST-Micro and Nordic, because working with Qualcomm is a royal pain. We also tried Feasycom and found them to be very unresponsive.

So it sounds like putting my hands on my head and spinning around as fast as I could while looking at the image probably got the CPU pretty close to right if not correct, my eyes surprised me.

The only device I've seen so far with Bluetooth 5.2 LE is the new Samsung Galaxy S21 FE 5G phone with the Snapdragon, it's out now, I haven't been actively looking for LE devices of course so I've no idea of any other products with it yet.  I've no idea how long it takes Samsung to pump out a new model phone but they've had access to it long enough to do so.

https://www.gsmarena.com/samsung_galaxy_s21_fe_5g-10954.php

It's chipset is reported as

Qualcomm SM8350 Snapdragon 888 5G (5 nm) - Version 1
Exynos 2100 (5 nm) - Version 2

[Cal_Cobra]

7 hours ago, Geotech said:

32b Cortex processors have plenty of horsepower for detectors. M4 cores (as apparently in the Legend) have a hardware multiply so they even have some DSP muscle. Almost all my designs use STM32 micros. The F-Pulse/TekPoint has an STM32L072, the walk-thru has an STM32L496, and another design has an STM32F767.

 

Oh sure I agree, they have plenty of compute power for this kind of stuff.  I read their datasheet on the ST website, and yes they do have a DSP (small).  32b Cortex processors are used by some vendors in lower end next generation firewalls (I have several of them in my lab from a competitor) and they are fine (mostly constrained by memory not CPU).  These are a SoC they licensed from ST adding their own custom ASICs on the die integration as well. 

Don't get me wrong, I'm not saying it's not plenty of power for a detector, I'm just saying in general, it's  not going to set the world on fire as far as CPUs go.  A Xeon Platinum 8380 it is not 🙂

7 hours ago, Geotech said:

Have you seen anything with 5.2 LE audio? I think Qualcomm has a chip that supports it and I've seen one set of 5.2-LE earbuds, but nothing else. No off-the-shelf headphones or transmitters. The companies I'm watching in particular are ST-Micro and Nordic, because working with Qualcomm is a royal pain. We also tried Feasycom and found them to be very unresponsive.

NM has had this project on the drawing board for about five years, perhaps not seriously until around three years ago (+/-) so I'd expect most of the hardware components were selected around then before BT 5.2 was a thing.

Carl is there anything on the circuit board Simon shared that you find particularly interesting, or is it just status quo as expected?