PICKINI - an easy to build PI detector

[F117]

For f117 How can i mesure without coil ?

Disconnect the coil.
Apply the power supply = 15 - 18V DC.
Measure the voltages at the 5V and 12V stabilizer outputs.
If they are OK, it means that you have excessive current drain that pulls down your supply voltage with the coil connected.

[nick holas]

I ve tested them , they works fine, where does it come ? What can i do more
I ve changed coil , nothing better.
When i disconnect coil, and switch on 3 tone,3 thick then continuous beep.
When i connect coil ,3 tone then noting!!
I think the hell is in my board and wants to play whit me!
Thanks

[F117]

When i connect coil ,3 tone then noting!!

This is the normal behaviour. 3 tone and then "nothing" execpt a 1Hz tick that changes into beep when a target is near the coil.

[vawn90]

Hi F117,

I have constructed the PCB according to the layout you shared in your website. But i faced some problems after that.

1. The buzzer start with a beep when i switch on then the buzzer keep sounding non stop. Is it work correctly in that way or the other way? According to the demo video, it shows that the buzzer only sound when it detects metal.

2. After the construction of PCB and attached along the electronic component according to the designed given, no detection happened.

3. i used PIC Kit 3 programmer to program the PIC16F1824, it seems not compatible.

4. When i load the file into the MPLAB IDE v8.92, it shown a lot of error after compiling.


For power supply part to every components, it is worked. I have shielded the coil according to your latest method of shielding.

Question:
1. I would like to know what version of MPLAB IDE did you used to upload your file to the PIC16f616 and PIC16f1824? and did you used HI Tech C Compiler?

2. Is it after shielding process, i can't check the inductance value anymore?

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Please do help me as this is part of my final year project. Urgently need to finish it asap. I would appreciate it very much!!!

[F117]

1. The buzzer start with a beep when i switch on then the buzzer keep sounding non stop. Is it work correctly in that way or the other way? According to the demo video, it shows that the buzzer only sound when it detects metal.

You can only connect a loudspeaker or headphones at the output, not a buzzer. When you hear the detection tone continuously, this means instability.
Try to turn the sensitivity potmeter to the minimum = 0V at the wiper. Then try it outside the house, away from noise.

i used PIC Kit 3 programmer to program the PIC16F1824, it seems not compatible.

I also use PICKIT 3 to program the 16F1824.
If your microcontroller is programmed correctly, you should hear a 3-tone "welcome" sound immediately after power-on.

When i load the file into the MPLAB IDE v8.92, it shown a lot of error after compiling.

You don't need to compile it with MPLAB IDE. The source file was originally compiled with the mikroC compiler.
It will not compile with MPLAB unless you modify some things.
I use MPLAB IDE V8.83 only to connect with the programmer. Then file->import http://users.telenet.be/willaert/MD/...ni_16F1824.hex and program.

Is it after shielding process, i can't check the inductance value anymore?

The shielding of a bundled coil should not really change the L value a lot. If you have an LCR meter or "passive component analyzer", you can measure the L value.
Make sure that the offset voltage is set to 8V with the 100K trimmer.

Good luck,
- Bernard

[vawn90]

Hi Bernard,

Thanks for the advises.
I have tried all the solution you shared. Here is the problem that i have solved.

1. After switch ON, 3 tone appear. (not sure correct or not - 1st tone, 2nd tone and then continuous tone)
2. The program has been successfully programmed into the PIC16F1824.

But, problem occurs such as the tone continuously sound non stop.
1. I connect a LED at Port 7, and after the 3 tones, it keep switch ON along with the continuous sound. Is it wrong?
2. I have changed to loudspeaker but problem still occur. I used 8 ohm, 0.5W speaker. What speaker did you used?

Please advise on this matter. Sorry for troubling you so much Bernard. Thank you

[bernte_one]

hello vawn90,

can you post or link a picture from the pcb layout which you have used?

[F117]

After switch ON, 3 tone appear. (not sure correct or not - 1st tone, 2nd tone and then continuous tone)

After switch on: 3 tone, then 4 ticks and then you will hear a detection tone when the detector is not stable. When stability is reached: a tick every second.

For all DC values to be measured: see post #61 in this thread. Check them on your board.
You can have the voltage on the sensitivity potmeter reversed ? So, that after switch on, you get 5V at the sensitivity instead of almost 0 V ?

I always connect headpones or a speaker of at least 30 ohms.
When the detection LED is ON, it means you have a continuous detection or unstable signal.

Is your power supply OK: 18V DC, at least 200mA ?
Make sure your test coil is well away from noise sources or metal when testing.

[vawn90]

Attached is the photo of my pcb layout and you will notice different in the component, as in my country, Malaysia will receive component at least a month from europe or etc. Except singapore.

I have measured all the reading from the Op-Amp and PIC..Every part follows the reading from post #61.

The detection happen when i connect prob from multimeter, one to ground and the other to port 2 of Op AMP, only then it works.
I built the circuit with breadboard and PCB. I compared both of them and both needs the same connection i have mentioned. I have checked the resistor of the multimeter which is around 1M. The sensitivity is not good enough as it could detect iron in few centimeter away only.

Is there any wrong with my connection? Please advise...

[F117]

Do you notice any different behaviour when you slightly turn the multiturn potmeter.
It should be adjusted for 8.0V at pin 3 of the opamp, but try to turn it up/down to see if a more stable point can be reached?
Is the ground connection of the opamp - pin 4 OK ?

Maybe also a picture of the copper side of the PCB ?

[mohandes]

hello vawn90,

can you post or link a picture from the pcb layout which you have used?

hi
my friend do you make this project ???can you send me pcb file.
regards

[F117]

mohandes,

all info on the PCB can be found here:
http://users.telenet.be/willaert/MD/...ectronics.html

[mohandes]

mohandes,

all info on the PCB can be found here:
http://users.telenet.be/willaert/MD/...ectronics.html

my friend do you use 1moil with this detector,

[F117]

my friend do you use 1moil with this detector

Sorry mohandes, but I don't understand your question.
If you mean 1 coil: yes, there is only a single monoloop coil attached - it is a PI detector.
Please read all the documentation on the web site.

[bernte_one]

i think he means 1meter coil