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Like to give your design a try...can we see hexfile soon,also is the sample delay adjustable or only in software?
Thanks
John
Thanks
John
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Hex Files
I have hex files here but I did a bunch of changes and didn't have time to test them and would hate to send something out that had a bug in it.Originally posted by johnandles View Post
I''m at work now and will be for the rest of this week but will get those hex files asap.
Btw: I did see another error in the schematic, the two rx lines need to be switched, I'll fix it when I get home...
Thanks for the interest!
JonComment
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hex files and updated schematic
I've attached a zip file containing the updated schematic and hex files
if you have any problems or if I've missed something just let me know
Thanks!
JonComment
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Thank you
Thank you for the schematic and code.
I will try to make it soon. Has anyone already made it?
Please tell me what are the encircled components :
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componets
The diodes you circled are just two diodes placed in parallel and opposite polarity of each other I used two BAT45 Diodes but I don't think it's that big of a deal
The Mosfet you circled should have a breakdown voltage no less than 500V and as low of capacitance as possible <100pf
here are some good looking options
model coss vds current rds(ON)
*FQPF6N60C 65pf 600V, 5.5 A 2 Ohm
FDPF7N60NZ 90pf 600V 5A 1.2 Ohm
*FQPF7N65C 100pf 650V 7A 1.4 Ohm
*FCPF9N60NT 140pf 600V 9A 0.3 Ohm
FDP10N60NZ 150pf 600V 10A 0.75 Ohm
I purchased the ones marked with asterisks but they haven't arrived yet, when they do I'll let you guys know what works best
Right now I'm just using a mosfet scraped off of a computer psu but anything between 400V - 800V capable of at least 5A should work, The lower capacitance the better!
some people have been using the IRF740/840 but it really isn't that important as long as it has a fairly low output capacitance (coss)
If you just want to buy one I'll bet the FQPF7N65C would make a nice switcher
they have it for $.65 at http://tinyurl.com/3px7b6e
Good Luck!
Jon
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Hello,I have recently recieved my USB ISP programmer from China,at this stage it has a ten pin cable with header plug,so I guess I will need to make a board to program the Attinys..Originally posted by pearl View PostThank you for the schematic and code.
I will try to make it soon. Has anyone already made it?
Please tell me what are the encircled components :
My other question (s), is the sensitivity control the sample delay,or is that fixed in software?
Also the audio is this a type of vco sound ,and is it a motion only detector...
Sorry soo many questions
Thanks ,Looking forward to your reply
JohnComment
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John
just program your chips on a breadboard, you only need 6 jumper wires
SilverdogComment
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In this detector the sample delay is what is used to determine the presence of a metalOriginally posted by johnandles View Post
so it's not necessary on this type of detector.
it's not a motion only detector but eventually i intend to put on some sort of slow ground balance
to compensate frequency drift in the oscillators.
Good Luck!
Jon
http://www.miymd.comComment
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I don't see a damping resistor in the schematic.Comment
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Damping resistor!
Good point, I'll update the schematic!Originally posted by hobbes_lives View Post
idk what to put though, It's something that should be calibrated by the user right?
different for every mosfet/coil combo.
on my unit I have a 1K Variable resistor in parallel with a 330 Ohm Resistor.
Any comments on this setup or should I add it to the schematic?Comment
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Nice job!
Highly Recommended DIY programmers I have tested :
http://electronics-diy.com/avr_programmer.php
http://www.lancos.com/prog.html
The first is a DB9 serial programmer, very easy to make. The second one is a DB25 parallel port programmer that also works really well. I had used both until deciding on usb.
However, I had a difficult time (as have others) getting USB programmers to play with Win 7. I tried hard using the ubiquitous USBASP clones found on ebay with very little luck. Until this day I have not upgraded my win 7 laptop to SP1 because I don't know if it will break compatibility.
Anyways, a usb programmer I would recommend is this one by pololu: http://www.pololu.com/catalog/product/1300
Can you spot it in the picture?
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That's fine for determining the optimal value of damping resistor to use, but it's probably best to use a permanent fixed resistor once the value is determined.Originally posted by jon-ecm View PostComment
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Tech Video
I took a video explaining the core concepts behind this machine.
http://www.miymd.com/files/6513/0245/5784/IMG_2342.MOV
if some of you have slow internet I can resize the video for you, just let me know!
Enjoy!
Jon
http://www.miymd.com
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convert to analog?
I've been looking for sources of noise and I think that the bottom line is that the analog comparator in the
atmel attiny series mcu is just not made to do what I'm trying to make it do,
I've schemed up a plan to make the rx frontend entirely analog, I will use a ultra highspeed/low noise analog comparator.
the tx will output pulses on two pins, 1 to drive the mosfet and another (clk) to try to match the output of
the analog comparator as closly as possible, when the two waveforms fall out of phase analog circuitry
will pick that up and produce a sound
ok enough talking, here's a graphical representation of the idea
I'd love to hear any comments on this idea, It's sorta like BFO but using pulse inductionComment
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