Arduino Nano PI Main Discussion

[Carl-NC]

Is it possible to use an IRF840 mosfet without too much changes? What would be the benefits or drawbacks of it? Thanks.

That would require significant changes, especially to the power supply domains. Best to stick with PMOS.

[Lukelearning]

Hi

I'm a bit stuck again. Before beginning construction the coil seemed fine, about 20cm strongish signal for a £1 coin but now I've mostly put it together this has fallen to closer to 2cm!

I'm really confused as the voltages seem OK. Although I can't seem to change the flyback voltage from the potentiometer on the pcb but its showing at -182v. The coil itself has an inductance of 0.32mh so that seems fine. Wave looks normal on TP6 it just doesn't seem to be anywhere near as sensitive as it was before I started putting it together.

Any suggestions would be much appreciated!


Thanks

[Qiaozhi]

Hi

I'm a bit stuck again. Before beginning construction the coil seemed fine, about 20cm strongish signal for a £1 coin but now I've mostly put it together this has fallen to closer to 2cm!

I'm really confused as the voltages seem OK. Although I can't seem to change the flyback voltage from the potentiometer on the pcb but its showing at -182v. The coil itself has an inductance of 0.32mh so that seems fine. Wave looks normal on TP6 it just doesn't seem to be anywhere near as sensitive as it was before I started putting it together.

Any suggestions would be much appreciated!


Thanks

You will need to use an oscilloscope to debug the problem.
The only adjustable pots are the sample delay, null offset for the preamp, and the audio threshold. None of these have any effect on the flyback voltage.

[Olabec]

Before I reinvent the wheel, has anyone done a surface mount component version of this project? Thanks

[GeoMax]

Hello Olabec,

Why do you need an SMD version of the project? It would do the same thing, but it's more difficult to solder.

[tomas.turcar]

Hello everybody. I would like to built this metal detector, but I can not probably find list of all parts. I wrote down all the parts from the pdf schematic file, and I found out Im missing U4 and U5. Than I was checking all the rezistors, but I do not know which of them are trimmers. Can anybody help me please? Im attaching the list of parts I found on the schematic file. Thank you

[Qiaozhi]

Hello everybody. I would like to built this metal detector, but I can not probably find list of all parts. I wrote down all the parts from the pdf schematic file, and I found out Im missing U4 and U5. Than I was checking all the rezistors, but I do not know which of them are trimmers. Can anybody help me please? Im attaching the list of parts I found on the schematic file. Thank you

The Components Parts List is in Appendix A of the book.