VDI-RODERICO

[roderico]

well done ! You should also add adjustable display time. As in the previous version.
Now the VDI number is displayed all the time and is not good.

This was done on purpose for remembering what was the last target, however, since there is still some space left in the pic I will add another menu entry for adjusting the display time in the next version. As a workaround you only need to lower the VDI threshold below ~ -75 and the ground signal will clear the display as in the previous version...

[Nandor]

Would it be possible to add a depth indicator only in pinpoint mode like measuring signal strength and display it in cm?

[roderico]

Would it be possible to add a depth indicator only in pinpoint mode like measuring signal strength and display it in cm?

It might be possible but it is not an easy task with this, just try with two different metal objects at the same distance and see the strength reading...

[roderico]

VDI LCD v1.2

I added the VDI display time option and compiled a new version. The VDI value is displayed only for a few seconds (adjustable in the menu) if no metal object is near the coil. This is useful along with the VDI threshold as reported by perkun.

[perkun]

Thank you very much!!

LED vdi looks also interesting.
A great solution would be to use 4 led.
1 for iron
2 for trash for vdi 0 to +20.
3 for the range of +20to +50.
4 all above +50
what do you think about it

[roderico]

Thank you very much!!

LED vdi looks also interesting.
A great solution would be to use 4 led.
1 for iron
2 for trash for vdi 0 to +20.
3 for the range of +20to +50.
4 all above +50
what do you think about it

VDI numbers depends on the size, thickness, etc of the target, just put two or three similar coins together to see it. So it you have a thin coin it could be in the range of 0 +20 and it is not trash. It is just a hint of what the target might be. Of course for known targets you know the vdi numbers. I think the safest approach with the leds is what Artyom suggested, i.e. ferrous/non-ferrous metals...

[roderico]

Thank you very much!!

LED vdi looks also interesting.
A great solution would be to use 4 led.
1 for iron
2 for trash for vdi 0 to +20.
3 for the range of +20to +50.
4 all above +50
what do you think about it

On a second thought, this could work very well as a replacement for the LCD, however, looking at the PIC12F683 data sheet pin 4 (GP3) might not be used for a led, so the vdi would only have 3 leds, or else to use a pic with more pins...

[Artyom]

VDI numbers depends on the size, thickness, etc of the target, just put two or three similar coins together to see it. So it you have a thin coin it could be in the range of 0 +20 and it is not trash. It is just a hint of what the target might be. Of course for known targets you know the vdi numbers. I think the safest approach with the leds is what Artyom suggested, i.e. ferrous/non-ferrous metals...

Good morning, Roderico. I think that there is no need to delay the glow, there should be a quick response. Held over the target, the LED blinked and went out. This is necessary in order to quickly identify several goals lying next to each other. And if there is a delay, the goals are determined as one or incorrect. Best regards, Artyom.

[roderico]

Good morning, Roderico. I think that there is no need to delay the glow, there should be a quick response. Held over the target, the LED blinked and went out. This is necessary in order to quickly identify several goals lying next to each other. And if there is a delay, the goals are determined as one or incorrect. Best regards, Artyom.

Good morning Artyom, some delays can be removed and/or optimized for quicker response, did you actually test the vdi with 2 leds? regards

[Artyom]

Good morning Artyom, some delays can be removed and/or optimized for quicker response, did you actually test the vdi with 2 leds? regards

I have not tested it yet, I just ordered the programmer and the details, made the wiring layout. I'll do it on 12F683 But first I'll check on the breadboard)) And you will overwrite the new firmware with small delays. Thank you.

[roderico]

I have not tested it yet, I just ordered the programmer and the details, made the wiring layout. I'll do it on 12F683 But first I'll check on the breadboard)) And you will overwrite the new firmware with small delays. Thank you.

I had a look to the code and removed the longer delays, now it works much better, however I need to do a few more tests. In order to remove those delays I had to add a resistor so the pcb layout needs to be changed. I'll also try to backport the code to the LCD version and then I would post them here...

[Artyom]

I had a look to the code and removed the longer delays, now it works much better, however I need to do a few more tests. In order to remove those delays I had to add a resistor so the pcb layout needs to be changed. I'll also try to backport the code to the LCD version and then I would post them here...

Do not hurry, share the results and together we will make a worthy indicator.

[roderico]

VDI LED v1.1

I compiled a new version removing the trigger delay for quicker response, reported by Artyom. I had to add a pull-up resistor of 10K between MCLR pin and Vdd because it added some noise to the A/D when turning off a led (even being disabled in the configuration). I also added up to 4 leds (perkun's idea), so you only need to replace the firmware (and/or some leds) to change between different versions.

2 led firmware:

D1 on for -60 < vdi < 0
D2 on for 0 <= vdi < 90
D1 and D2 on -> op-amp in saturation and alternating on/off for calibration
D3 and D4 not used (no need to be in the pcb)

4 led firmware:

D1 on for -60 < vdi < 0
D2 on for 0 <= vdi < 20
D3 on for 20 <= vdi < 45
D4 on for 45 <= vdi < 90
D1 and D2 on -> op-amp in saturation and alternating on/off for calibration

I tested both with a PIC16F88 but it should work with PIC12F683/675. In the attached files there is also an example pcb layout that could be used for this vdi:

[roderico]

VDI LCD v1.3

Here it is the version with the trigger delay adjustable in the configuration menu to set a faster response. To remove the delay as in the led version you need to set it to 0ms and to recover the previous version value you need to set the delay to 500ms. This version also discards some cases where the sampling is incomplete and gives wrong vdi numbers (I'm using a 10k resistor between MCLR pin and Vdd in my vdi, however I haven't tested the firmware without the resistor while reducing the delay to 0).

[roderico]

Here it is the version with the trigger delay adjustable in the configuration menu to set a faster response. To remove the delay as in the led version you need to set it to 0ms and to recover the previous version value you need to set the delay to 500ms. This version also discards some cases where the sampling is incomplete and gives wrong vdi numbers (I'm using a 10k resistor between MCLR pin and Vdd in my vdi, however I haven't tested the firmware without the resistor while reducing the delay to 0).

This version has the default VDI interval in [-90,90], however, if you cannot see silver (i.e. vdi>90) then you need to change it back to [-90,180]