Arduino mega flc 100 code send data with Hc-05 ?

With flc100 and arduino mega pleas...

Yes, I have some little parts of information - but not from sure sources. Last week I read post for end stage of GPZ TX stage and in this post was mentioned half-bridge end TX stage but without serious information.

Must check old post by Kev, daemon, bklein

Explanation for how ML GPZ idea works in the patent is too complicate and not clear to be useful for design of the TX part of GPZ7000.

This some info from oscilloscope
this irf9540 gate

This coil
...

how it look like TX-pulse width?...

sorry kt315 tired mistake irf9540...

Unfortunately I don’t have it, I saw that fet on gpz board ...

Hi Op04,
To answer your question, we need exact schematics of the TX part of the ML GPZ solution (if that's not secret yet).

you do not have a signal (impulse) on the Gate of mos-fet. why you write LF9540?

One more thing to think is why ML put 240V fet on their gpz because in that case coil discharge current is lower vs if we put 500V fet

Hi boilcoil,
It will be useful information how to implement in PI MD active samples for more real Fe/non-Fe discrimination. Maybe the samples during TX-ON pulse will be more useful for this discrimination. But in this case, I have a question - how to do ground balance in this case. Any MD without...

This is the timing of old good SD 2000 Minelab MD. Now is 21-st century! Let to try to do some new in this area!

Hi,

the TX-pulse width is probably not correkt or you have a fake IRF MosFet from China.

Also in these times was popular 1.2V NiCd accus. 12pcs. by 1.2V also make 14.4V with end voltage of 12 x 1V=12V

hello everyone
what makes lf9540 so so so hot
please any idea...

Hi,
The oscope pictures for the first variant of the schematic of the TX part of the detector points very equal parameters for positive and negative peek voltages on the TX coil - as voltage and time to decay (360V and 5us) . Maybe it is not so difficult to use P-ch and N-ch MOS FETs in half-bridge...

https://howtomechatronics.com/tutori...dule-tutorial/

Thanks for the feedback...

For example arduino nano atmega 328p

Please help me...

At the moment the VLF mode is winning ... The ccpi did work but there was more noise. I suspect the additional harmonics present in the system each contribute more noise than the more frequency limited VLF.
I am waiting on boards from China to replace the FPGA.
The transmit board could...

I keep calling myself but the phone is always busy....

Your book should be in every public and state library around the world. Both public and state libraries routinely purchase books in various formats (physical and digital).
These acquisitions are crucial for maintaining and expanding library collections.
​
Libraries often purchase...

Hi Moodz,

I've made a PCB based on Carl's AMX TX implementation of your CCPI circuit but made provision for the resonant capacitor and using IPB95R310PFD7 FETS. These are 950 V devices.

So far, so good - all seems to work OK so far, but I'm now deciding which path to follow,...

Жди. Скоро информация будет. Wait. Soon we, me and GeoMax will give information.

Здравствуйте. Я пытался сделать печатную плату в Sprint Layout, но только запутался. Сижу учу Dip Trace...

Hello AhmatAhmatov1959,

We're making progress. We're currently finalizing the PCB design.​

Amazing book, I wish I had known of it earlier. Thanks for sharing your knowledge!

Hello Detectorist#1. I really want to make a metal detector using this scheme. Any progress? Sorry for my English....

I dont think you understand what the problem we are solving is .... The target spectrum can only be in response to the TX signal .... A simple bandpass filter you propose can remove low frequency components but it cannot remove modulation components due to noise / earth field etc.

Below...

Very interested in this, although I would like to make this with 2 fixed probes and 2 movable probes as used on Frobisher etc. I guess I could just use it without the MUX boards. Anyone any ideas on this configuration?

That looks like a version of the QED pi. Search forum for QED...

It is said that the depth of this board is okay, can anyone provide some details?

​​​...

Unfortunately, I'm looking for that too.

1.When designing a band-pass filter before demodulation, you need to find out what Spectrum the target signal has. When I mentioned the bandwidth, I meant the Spectrum of the target signal. If the target's constant time is 1u, then its Spectrum starts from 1 MHz and above.
Harmonics of the pump...

IGSL was built on the Tesoro core design.

GMT King Cobra is sure full copy of Tesoro core design. just a Note. do not waste your time. ...

This is the second part of the test, here is the first part:...

This may explain what is happening in the MAGPI 3 circuit for example. The amplifier A amplifies the signal from the RX coil however the only place the 1Khz LPF is in the feedback path ... so the noise ( earth field and EMI ) that is modulated onto the wanted signals ( target signals ) is not amplified...

Not entirely sure what you are referring here .. however If you have a PI that works at 1Khz repetition ... lets say we have a equal turn off an on time ( ie square wave or symmetrical wave ) then the fundamental tranmit frequency ( ie lowest frequency the target sees ) is 1 khz ..... because we are...

Although at second glance something worries me, something is wrong here. 10 us of response from the target corresponds to 100 kHz, on the other hand the cutoff frequency of the low-pass filter should be less than 1 kHz.
Which in turn provides 1 kHz bandwidth of the source signal at best.
...

A portable lab in your pocket.
​

https://www.aliexpress.com/item/1005008412907994.html

OK, thanks,
When I have more free time, I can try it....

... I was not suggesting that measuring the flyback pulse width in the manner described would lead to a worthwhile improvement in discrimination or anything else for that matter. I was only trying to help the OP with a method to do it. In practice there are alot of error signals that will mess up this...

That will work ... similiar to minelab patent US5576624 ??

Where longer and shorter transmit pulses are used.

​...

I think of something else:
Let's take two identical samples using the classic way for PI metal detectors, but with a very small delay (immediately after the saturation time of the op-amp). Let one sample be energized with a sufficiently long pulse and the other with a very short pulse.
If...

..there are many ways to measure pulse width ... the Lammerby graph in post #1 is for frying pans and horseshoe sized targets .. you will never see that response for coke cans at 1 meter from the coil.

The proposed circuit is similiar to snubber circuits used to control or limit the peak...

I'm not familiar with the PIC16F1824, but a little hunting says the max ADC clock is 4MHz, so 1 TAD is 250ns. TACQ is 8 clock cycles, so one A/D measurement (according to boilcoil's equation) would be 11.5 x 250ns + 2μs = about 5μS. Still a lot faster than mine. I'm using an ESP32. I need to dig further....

For one complete sample at 10-bit ADC, 11.5 TAD + TACQ is required.
The TAD is determined by the frequency of the ADC, which is not the frequency of the processor. The minimum TAD duration for this type of processor is not recommended to be less than 1us.
So the time is a bit longer.​

Thank you, Eduardo for the tests done and for sharing them in the forum. Thank you again

Hello Boilcoil. I've tried with 74HCT4066, 74HC4066, CD4066, and CD4016. There's no difference in depth. The only difference I notice is that the Ground Balance drifts very slightly, and I have to readjust the potentiometer. The drift is minimal. I've tried with a Hot Rock.

??
On the old PIC 16F1824 I used for the Pickini project, running at 32 MHz, a 10 bit AD conversion took 1 microsecond...

The idea of temporal sampling is to measure the pulse width, not sampling any voltages....

This is the one you want. 3-in-one oscilloscope, signal generator and multimeter. No need to calculate anything-all parameters of waveform are displayed on the screen. Amazon price $88. Good value for money. 50MHz dual channel. FNIRSI 2C5CT


Also get the analog scope, dual channel....

I misclaimed 13μs as my A/D read time. I thought I'd better recheck it and found it to be between 40 and 60μs. I've been looking at a few ways of making it read faster using lower level calls.

Thank you!!

congratulations!

You correctly noticed about the transistor tip32, the mistake was mine. With the MOSET the circuit works well. As with the speaker.​

Hi boilcoil,
I just assembled one simple tester for 4016 and 4066 analog switches.
The schematic is attached.
You are right - these switches have problem when voltage between input and output of the switch in ON state is more than 0.4V-0.5V. Only in the datasheets of 4016 and 4066...

This was invented by MD-engineers so that MD-users would not think about ferrite calibration, about setting angles and phases, etc.)...

​***Hold in Reset mode is enabled***
Can you help me with what is causing this problem?
​...

Hello Eduardo,
I watched the video, really good design.
I noticed that all IC are mounted on sockets, which is a good choice for hobby electronics.
In the project, you use analog switches, type 4066, which, however, have one feature that may or may not be useful, depending on the specific...

Do you mean the frequency formula 1/t=f
Or you only mean to consider the features of the scope such as the number of channels it has, etc...

Thank you. It's a 2-way street, I've learned a whole lot from everybody. ITMD has been a way to put it all together and share it back.

Hi scs-bg,
You are at the beginning of the design of PI detectors, but do not be discouraged - all future knowledge is ahead of you! All we started from a not very big starting point. Ask and do, ask and do!
The TIP32C transistor is not Darlington type and haven't internal diode. This is...

Hi Carl, many of us, ITMD3 readers, are very grateful for your efforts in favor of DIY detectorists to be involved in this exciting hobby!

MAGIC12, I write ONLY by using my email address. It is [email protected]. You can contact me using that email address. I write and understand only
ENGLISH, so lets talk back and forth in that language. What are you seeking? If I have it, I will negotate and trade it IN SECRET. Neither you or myself...

I should have added some calculations to my earlier post ( did not have my calculator handy ):
I worked out the equivalent parallel resistance of your TX coils as below:
Small coil: R parallel = 666 Ohms
Large coil R parallel = 588 Ohms
So if you add extra parallel resistance...

Thanks for all the input so far !
I am fully aware that discrimination based on the decay curve is not exact science. But then again, even my Deus2 gets it "wrong" "sometimes"...
The question was mainly triggered because I made the Pickini temporal sampling detector almost...

That's the purpose of every circuit in the book....

It is true that digital detectors have less detail and are not difficult to make. Analog detectors have a lot of detail and are difficult to repeat.​

The OPs diagram is correct however only for large selected targets as pointed out above.
Note also the diagram is a "diode clamped" voltage waveform ... this is extremely bad in a PI detector for the following reasons.

1. The clamping process effectively demodulates to...

Thanks for the advice. A friend made an Arduino Nano, a really good project. But these are two different detectors - digital and analog. I have seen that analog ones in practice give more even results. They show weak signals better and are more informative. I repeat that this is my opinion.

I might be boring if I repeat some things.
In 2012 I bought an XP Deus 1 and it was a very significant (one might say "tectonic") turning point in my prospecting career.
And then there was a long period of boredom and nothing new and interesting.
Until I bought a Vanquish...

I'm on the forum every day.
But I have nothing useful to contribute to the current thread, therefore I am silent.
My Bipolar PI is waiting. Until I put the 74HCT4053; I will not be sure about the next steps.
In the meantime I've beefed up my arsenal with the Vanquish 540 and my current...

Have a look at the Arduino Nano Pulse Induction Metal Detector Project -> Arduino Nano Pulse Induction Metal Detector Project - Published March 2021​
This fixes the problems of the Surf-PI and provides better results.

The above is correct. Sampling the decay curve will only provide discrimination by conductivity.
To reject ferrous targets, you need a different approach....

After 20 years since its appearance, the Surf Pi remains one of the best pulse induction detectors. It has two minor problems that can be easily fixed. The reason for the first is the reverse-connected diode in the transistor type 32 . It changes the smoothing of the reverse voltage in the search coil....

Special greetings to ivconic...

Hello ivconic
What happened, bro?
Where did you run away - you're not there?
The forum is not the same without you....

Decay curves are based on the timeconstant of the target.
Unfortunately, ferro targets play with eddy currents and with their high magnetic permeability, so they can have practically any time constant depending on the size, shape, orientation to the coil, etc.
In short, the curves shown...

Your questions:
1/ Is this decay diagram correct - is there really a time shift depending on the type of metal near the flyback top ?

I would say the diagram is wishful thinking but will be happy if proven wrong because I really want it to be true. I've seen a few comments on being...

I've got the same diagram. I haven't noticed the same effect though. I have been working on a PI detector for about six months. It uses an ESP32 and samples the return waveform at 10 points using the inbuilt 12 bit A/D. I've tried a few different configurations of trigger pulse duration and curve...

The best working hybrid detector is with a DD coil. Sound from a pulse induction channel. Discriminator with a meter with an arrow. Separate channel, signal when transmitting. Both channels without movement, with a reset button. Both channels work with a signal from the receiving coil. In this way,...

Back in time, when Radio Shack was still in business, I bought their booklets. I used to stop there and buy my electronic items as well.
So I scanned each booklet, as Radio Shack is "out of business" now, and not even in business "mail order" either....
MELBETA
...

I suggest lowering the TX Q-factor of the higher Q coil ( 28cm ) so that it matches that of the larger coil. Do this by adding a resistor in parallel with the TX winding.

Also: I am puzzled by your LCR meter readings. Surely, your TX coil has a low resistance, like about 3 Ohms ? Why is...

I came across this page "Pulse induction metal detector with DSP" by Lammert Bies.
https://www.lammertbies.nl/electroni...metal-detector
It includes this diagram of three decay curves :
- no target
- ferro target
- non ferro target



...

I made a hybrid pulse detector 20 years ago, long before Voodoo. It turned out that due to the influence of the ground, incorrect discrimination of deep-lying objects occurs.​

I'll probably use the Raspberry Pi Pico 2 as the controller for the AK5578 and try to get the I2S interface to the chip implemented in its programmable PIO so that I can leave the cores free for processing.

Busy creating the Kicad part symbol for the AK5578 now, then will put a schematic...

Looks like a nice chip ... the AD7760 is strange ... the Eval board all built up and tested is only a few dollars more than the one off chip price ??? Be interesting to see what you can make of the AK5578.
I was tempted to move away from the FPGA to a CPU ... but will stick with the FPGA now...

14.4V is from 4xLiPo accus and end voltage is 12V. For charging you will need special unit with equalizing function - relatively expensive variant
15V is from 10xAA alkaline batteries - more cheaper variant but end voltage is down to 10V - this will reduce the TX power more then in the first ...

I just received the 540. I gave my 340 with the surcharge.

​...

Excuse me, now I read that it is a half-sine wave, so I am correcting myself....

​I share the link on the archive and you get my email address. somebody evil intruder did harm me and subscribed on VIOLITY spam messages.
LOOK - this is NOT my phone number, i am NOT living in Ukraina. what going with YOU there??? you answer me by mud on my good!...

Does anyone have a photo of the deus 2 coil board?

Hi Moodz,

Given the price of the AD7760, I've been having a look for suitable alternatives for direct sampling and think the following may be quite decent - I've got one on order to play with, just need to knock up a test PCB.

https://www.akm.com/global/en/produc...-adc/ak...

Yes I have seen that article it explains basically how to solve the problem.
For modelling I used the free trial of MATLAB. But ltspice is fine for modelling the demodulating preamp.

As soon as you mentioned it, I immediately remembered this article:
https://www.analog.com/en/resources/...oaches%20zero.
A long time ago...

I have to agree 100%, I've had my Deus 2 for over 1 year now and can say, with the 9" coil it is superior to even the Equinox 800 which I had for 3 years prior to the Deus 2. You must spend time to understand what the audio is conveying to you. But it takes time. Sure, you can go to a site and...