PICKINI V4 - an easy to build, self adjusting PI detector

[ripsdevala]

Good day Bernard sir

I was on the beach yesterday for 3 hours, this detector cant withstand iron sand, the only way is to decrease the sens so it will reject iron sand, when i try to 2.5cm brass coin it detect at 15 cm with low sens, not a half of 10k resistor, when use more sens, it will beeping continuously, on the beach the detector behave almost like at home, its somekind get emi interference there, its a shame I don't have the video, I lost part of my shaft on the way there.
And I can't find anything, even a nail.... Idk

[F117]

Did you keep the coil away from everything - in the air - after switching on the detector ? That is when the calibration is started.
I never had this experience, but then again we don't have "iron"sand on the beach...

What did you do differenc compared to your previous beach test that did work?

[morganton]

Let me try to find that module at local ol shop, or charge battery externaly for the last option.
Pikini is very picky with voltage i think, i will try 14v to make it last longer.

I saw a photo on (I think) this forum of a guy who cut off the handle end of a cordless drill and attached it to the end of his MD by the arm rest and then used the drill battery to power the detector. There are several choices for voltage including 12.2V and 14.4V. You can easily detach the battery and put it in the charger at the end of the day. I've thought about building one like this, but have never got around to it.

[ripsdevala]

Did you keep the coil away from everything - in the air - after switching on the detector ? That is when the calibration is started.
I never had this experience, but then again we don't have "iron"sand on the beach...

What did you do differenc compared to your previous beach test that did work?

Yes, i use all the procedures, last time its okay, doesn't get emi with almost at max sens, there is no black iron sand, crowded beach many garbage on small beach.
On latest beach, much washed iron sand bellow beach sand surface, navy base near there, long...long beach, few tourist, isolated beach
Or maybe I use 11v 8xAAA battery

I saw a photo on (I think) this forum of a guy who cut off the handle end of a cordless drill and attached it to the end of his MD by the arm rest and then used the drill battery to power the detector. There are several choices for voltage including 12.2V and 14.4V. You can easily detach the battery and put it in the charger at the end of the day. I've thought about building one like this, but have never got around to it.

That was good idea, but what about battery protection, if the battery discharge bellow recommendation its will broken, that's what I know. Or should use it with the battery housing from cordless drill pack, I think there should be PCB protection there, never open mine.

[geoscash1]

Finished but not quite right yet

Well finally finished up my pikini, seems to have loaded hex correctly as when firing up the board it gives the initial double beep, then goes into a slow tick for about 25 seconds but then goes to a constant low tone with no detection.

Everything is connected correctly but did see where the bs170 may have different pinouts, not exactly sure how to check that to make sure it is placed correctly but I did connect the scope and added some shots below.

It looks as though it has the pulse, the flyback and the pulse at the gate of the fet so not sure what to look for as what may be causing the issue other than the bs170.

Any ideas??

voltages below along with scope pics.

LM318
1 = 8.0v
2 = 2.09v
3 = 2.51v
4 = 0v
5 = 8.65v
6 = 9.48v
7 = 10.30v
8 = 0.71v

16F1824
1 = 5.01v
2 = 0.19v
3 = 0v
4 = 0v
5 = 4.78v
6 = 0v
7 = 0v
8 = 4.77v
9 = 4.76v
10 = 0v
11 = 2.45v
12 = 2.36v
13 = 3.17v
14 = 0v

(all voltages are +v or 0v unless otherwise marked)

pics

[F117]

pin 10 PIC voltage is wrong - it should be more than 0V - this is the reference voltage for the internal comparator. This is generated as PWM from pin 2 and filtered with R19 / R20 / C13 and then fed into pin 10.
Check this voltage with the scope during the initial calibration cycle.
The other pin of the comparator is pin 8/9. Measure there with the scope, this should be a negative going flyback pulse from 5V down to 2V.
The pulse to the IRF740 gate should be 100 microseconds wide.

The low tone after the calibration cycle is the COIL ERROR sound: no flyback is detected at pin 8/9 inputs of the PIC.
At first sight, I don't see anything obviously wrong on your PCB.

I assume you used the hex file as is, and not rolled your own ?

- Bernard

[morganton]

Geo, your PIC's pin 4 should have around 5 volts. You can check the project settings for the PIC to see if you might have "MCLR Pin Function Select" enabled (it should be disabled) and also to match F117's other recommended settings. Also, I had the "Oscillator Selection" incorrect which caused the PIC to run too slow. It should be "INTOSC oscillator: I/O function on CLKIN Pin". These incorrect settings caused mine to not work. See posts 84 and 227 above.

[WM6]

Hi Bernard

Did you think about low consumption version of PICKINI in pin-pointer design, powered by ordinary 9V battery?

Do you have such pin-pointer PICKINI solution?

[geoscash1]

pin 10 PIC voltage is wrong - it should be more than 0V - this is the reference voltage for the internal comparator. This is generated as PWM from pin 2 and filtered with R19 / R20 / C13 and then fed into pin 10.
Check this voltage with the scope during the initial calibration cycle.
The other pin of the comparator is pin 8/9. Measure there with the scope, this should be a negative going flyback pulse from 5V down to 2V.
The pulse to the IRF740 gate should be 100 microseconds wide.

The low tone after the calibration cycle is the COIL ERROR sound: no flyback is detected at pin 8/9 inputs of the PIC.
At first sight, I don't see anything obviously wrong on your PCB.

I assume you used the hex file as is, and not rolled your own ?

- Bernard

Hi Bernard,

yep, I used the hex as downloaded from your site.

I rechecked the voltage at pin 10 with my scope and still get no response or 0v. I tried the headphone test and can clearly hear a tone which is saying the coil is being pulsed, at least that's my understanding from other builds.

I measured pin 8/9 with scope and it definitely goes from 5 to 2v but is positive going, not negative. I used the tp on board for this test.
checking the coil with my scope leads across the coil connections gives a good signal (as shown in previous pics).

Let me try to reload the hex, recompile and write to the chip, I'll double check all the settings (mclr etc) and then go from there..

thanks for the quick replies guys, much appreciated...

[F117]

You could also check pin 2 with the scope: this should be a PWM output, that provides the comparator DC reference after filtering.

The ticks you hear after the welcome sound have no relationship whatsoever to the presence of a flyback pulse.
The flyback pulse at the test pin of the PIC should have this form : 2V bottom, 5V top



The "slice level" is the filtered PWM DC voltage to the comparator.

[F117]

@WM6: this version of the PICKINI detector is far from ideal for a pinpointer since it requires a calibration phase after power-on that can take up to 20s.
This is not something you would want with a pinpointer.

[WM6]

@WM6: this version of the PICKINI detector is far from ideal for a pinpointer since it requires a calibration phase after power-on that can take up to 20s.
This is not something you would want with a pinpointer.

OK, thanks. Nevertheless, interesting design.

[geoscash1]

Well, pulled the chip, erased and started over. Originally I just used my pickit 3 to import and download the hex file. Now seeing there needs to be some things set on the chip prior to programming, I am not sure how to get to the screen you guys show over on page 4 where the mclr and other items are disabled.


I tried reloading the program as I did previously and now the chip does something similar to someone elses, no start up beep, no sound or detection but the pinpoint button pressed will give the startup beep and nothing else. I have no wave forms or info on the scope now either.

I have the pickit 3 connected to mplab ide now but still cannot find where you change all those chip settings, any help with that would be great because at this point I think that is the issue.

Thanks in advance,
Geo

[morganton]

Well, pulled the chip, erased and started over. Originally I just used my pickit 3 to import and download the hex file. Now seeing there needs to be some things set on the chip prior to programming, I am not sure how to get to the screen you guys show over on page 4 where the mclr and other items are disabled.


I tried reloading the program as I did previously and now the chip does something similar to someone elses, no start up beep, no sound or detection but the pinpoint button pressed will give the startup beep and nothing else. I have no wave forms or info on the scope now either.

I have the pickit 3 connected to mplab ide now but still cannot find where you change all those chip settings, any help with that would be great because at this point I think that is the issue.

Thanks in advance,
Geo

I can tell you how to do it with mikroC which I think is easier than mplab. And I think you have to add a compiler to mplab to get it to work. MikroC already has the compiler. What you want to do is install the mikroC program and copy F117's source code written in C from his website (not his hex file) into a new project. Then, at the top of the page, click on "Project" and then "Edit Project" There, you will see the settings for the oscillator, MCLR, etc. that I talked about above. Modify the settings in accordance with post 84, and then build the project by clicking on the "Build" tab and then "Build" again. What you have then done is generate hex code that has the correct project settings. Make a note of the file where the hex code mikroC generated is stored.

Then download the PICkit 3 software -- here is a link http://en.freedownloadmanager.org/Wi...Ckit-FREE.html -- install it, hook up your programmer with the PIC installed and open the PICkit 3 software up. It should pick up your PIC. I actually use the PICkit 2 version, but I think they are about the same. Import the hex code from the project file that was created by mikroC.

I think that PICkit 3 already has the correct file for the PIC 16F1824 but if not, you can follow the basic procedure I wrote up in post 215. You just need to find the PIC 16F1824 in the list (also see post 215 above for how to find it).

First erase your PIC and then install the hex code and you should be ready to go.

The good news is that you are very close to getting the Pickini 4 to work--you just need to get the right program on the PIC. Pin 4 of this PIC is the MCLR pin. However, it can also be used as an I/O pin if you disable MCLR. That is how F117 is using it. So, when you push the "pin-pointer" switch with MCLR enabled, you are simply resetting the PIC. In addition, your PIC probably has the wrong oscillator setting which means it is running too slow. All of this is fixed in the project settings.

If all else fails, pm me your address and I'll mail you a PIC with the correct program installed. Then, when you get a chance, you can mail me a blank PIC back and we will be even on our inventory.

Let me know if you get stuck.

Dan

Edit: To copy F117's source code in C, open his file up (http://users.telenet.be/willaert/MD/.../v4/Pickini4.c) with wordpad (or another program like it) and then copy all of the code and then paste it in a new project in mikroC.

[ripsdevala]

Edit: To copy F117's source code in C, open his file up (http://users.telenet.be/willaert/MD/.../v4/Pickini4.c) with wordpad (or another program like it) and then copy all of the code and then paste it in a new project in mikroC.

Heloo dan, i try to compile with the source code from F1117, but its stuck on some parameter that i dont know when i try to build hex, im not a programer.

@geocash
I use standalone pickit3 programer and work normal, im not turn on the pin point button when first start, otherwise it will stuck forever.