surf pi 1.2: building my first detector

[6blacx]

I did a step by step video series on building the Surf PI, you can see them here:
https://youtube.com/playlist?list=PL...UGJdTK59YEC2gE

OK sir, I'll try to learn. Thank you very much

[kt315]

Thank you for the quick response, sir.
is it true like this

[ATTACH=CONFIG]54671[/ATTACH]
[ATTACH=CONFIG]54672[/ATTACH]

good now but why you get 5kHz i can not understand. you have to see 600Hz.

[BC547]

Looking at the scope image 2.jpg, it shows a pulse period of ~1.6 ms = 600 Hz.
The 2 cursors left and right of the trace are probably the level at which the frequency measurement is done and this seems to be in the noise level.

[kt315]

oops! i did not look at division, so then thats good. tnx F117.

[6blacx]

Hello, all. finally found out the problem came from U4 CD4093, everything I got didn't work, after I bought it
hcf4093 finally surfpi is working and now it can detect coins around 10cm. the detection is good but not maximal I will try to repair the coil with a protector.


Sir for now I have something to ask, pot tune, is this pot can not be fully opened? i can only open about 30%, any more than that will make a lot of noise and can't detect the object

[Justihnno]

I followed your instructions and made the PCB at home instead of using an industrial process. It works well, but I would like to measure its performance on the oscilloscope . I am new to this field and I would appreciate it if you could show me how to connect the oscilloscope probes to the right pins for getting similar results. My PCB does not have the test points that yours has, but it is otherwise identical.

[Carl-NC]

Sir for now I have something to ask, pot tune, is this pot can not be fully opened? i can only open about 30%, any more than that will make a lot of noise and can't detect the object

Yes, the tuning pot (threshold, really) has more range than is needed. Set it to where there is a barely audible tone.

[Carl-NC]

I followed your instructions and made the PCB at home instead of using an industrial process. It works well, but I would like to measure its performance on the oscilloscope . I am new to this field and I would appreciate it if you could show me how to connect the oscilloscope probes to the right pins for getting similar results. My PCB does not have the test points that yours has, but it is otherwise identical.

TP1 & TP2 are labeled on the schematic and the videos show where to probe otherwise. What else are you needing to know?