Arduino based VDI!

[Daren]

@Davor
you should take a look at STM32 line of MCs. You can do 5Msps @12 bits (F3 F4 models). Low power models can do 1Msps 12 bits. (low power line is L0 and L1)
I worked with STM32 F1 and F3 F4; all very nice MCs. It will be more difficult to program them than Arduino, but ADCs are much faster on SMT32. (I think I posted this into before, mabe in other thread...)
IAR embedded workbench works very nice with them. StmCubeMX lets you configure the pin easily..
Teensy 3.1 is another nice MC, but ADC can do 800Ksps at 13 bits

[Davor]

The whole idea of an arduino is to have a simple programmable sensor module capable of performing some data crunching and networking. Convincing an ADC to perform beyond its bit depth is challenging the purpose of the exercise. I can make an arduino act as a whole discriminating detector, even as a multifrequency one, but the very notion that performance will be crippled due to a stupid ADC says: don't do it. It can perform as a nice VDI though.
My strong opposition against VDI so far was that it is a mere gimmick and a power hog. Low power MCU variants tend to eliminate the power hog argument though.

[Krzysztof]

The whole idea of an arduino is to have a simple programmable sensor module ...

http://www.wino-board.com/
Best regards Chris.

[Daren]

My strong opposition against VDI so far was that it is a mere gimmick and a power hog. Low power MCU variants tend to eliminate the power hog argument though.

Depending how VDI is done. Most of the time I can tell what coin it is before I dig it with TGSL + my VDI. I can also tell if the object if irregular (foil like) or more compact like coin (foils give jugged signal profile) . This is not absolute info but just hints that help you to decide if you want to dig. (You may not want to keep digging cents, but you will quarters).
Power usage is not really an issue with Arduino Mini Pro, also make sure you don't run LCD backlight LED at full blast.
I think VDIs are really useful. There is a lot more info that can be given to the user than just a VDI number. The profile of RX signal as coil passes over the object is very informative. Show strength and phase of the signal in time. When all that info gets compressed in to a single VDI number a lot is lost. Another idea is to use the RX strength to control sound strength and RX phase to control sound pitch. That may be even more useful, you should be able to train you brain/ear to different target responses much easier than keep looking at the signal/strength plots. Plus this can be done easily in analog circuitry, no MCs needed.

[Virdi_248]

I leave my files for all who wish to use.

I do not use decoder. My LCD illumination is controlled by a switch. On/off only.

GEOTECH thanks especially to members

Prospekteur Darem.


TGSL EDU_Arduino_Vdi part 1.rar
TGSL EDU_Arduino_Vdi part 2.rar

Missing two libraries necessary for Arduino. They have to search for the network.
LiquidCrystal_I2C
MenuSystem


Coming soon will show a video. greetings

[Davor]

Depending how VDI is done. Most of the time I can tell what coin it is before I dig it with TGSL + my VDI. I can also tell if the object if irregular (foil like) or more compact like coin (foils give jugged signal profile) . This is not absolute info but just hints that help you to decide if you want to dig. (You may not want to keep digging cents, but you will quarters).
Power usage is not really an issue with Arduino Mini Pro, also make sure you don't run LCD backlight LED at full blast.
I think VDIs are really useful. There is a lot more info that can be given to the user than just a VDI number. The profile of RX signal as coil passes over the object is very informative. Show strength and phase of the signal in time. When all that info gets compressed in to a single VDI number a lot is lost. Another idea is to use the RX strength to control sound strength and RX phase to control sound pitch. That may be even more useful, you should be able to train you brain/ear to different target responses much easier than keep looking at the signal/strength plots. Plus this can be done easily in analog circuitry, no MCs needed.

I'd say there is a hope for you and the like-minded people. Your ears are completely capable of discerning lots about the target geometry, and you don't need a VDI to simply hear it.
I searched for 4 channel ADC with 24 bit resolution that may be used with Arduino, and I found ADS1253. It should provide some serious advantage over Arduino's own ADC.
It is supposed to suck little power and have good dynamic range. Price should be around an Arduino board, so it is OK.
You are right about doing it all in analogue circuitry. Some people call the pitch setting according to the conductivity - an audio VDI. Since that's precisely what I need, I'll most probably go with analogue anyway. Arduino with a proper ADC may have some serious edge over analogue in a multifrequency solution.

[Davor]

http://www.wino-board.com/
Best regards Chris.

I'll see about this one. Wireless may be interesting, yet it usually means using lots of energy.

[ivconic]

Hello Don!
Any news, upgrades?
With huge delay i got my UNO on the bench...

[Richlsdorfite]

A good alternative to Moteino could be Teensy 3.2 (MK20DX256 - 32 bit ARM - Cortex-M4 - 72 MHz).
37 ksps for 16 bit ADC, seems to be quite good for VDI purpose.

I find this VDI made with PIC 18F4520 : http://www.aspeluut.nl/metaaldetector.php

[Davor]

Teensy 3.2 seem to have nice specs, but it is also a power hog

[Richlsdorfite]

Is it a problem ? Nowadays batteries can provide enough power ;-)

I will try to port Arduino VDI code to Teensy 3.2.

[hugo]

Hi all,
I've been away from the forum for a while ...
But do you ever think about 1602 OLED display ?
The consumption is divided by 10, about 10-15 mA.
And It's sunlight readable.
Regards,
Hugo

[ivconic]

[WM6]

Look at this instant hybride board:

[Richlsdorfite]

Hi all,
I've been away from the forum for a while ...
But do you ever think about 1602 OLED display ?
The consumption is divided by 10, about 10-15 mA.
And It's sunlight readable.
Regards,
Hugo

I will try to. We can find this display for 19$ on ebay http://www.ebay.com/itm/IIC-I2C-1602...-/161162845021