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Archive for the ‘Fix me.’ Category

Floating voltages and bad GND connections — getting zapped and worse

August 12th, 2009

Nothing good can come from a freak idea after mi…..
Wait!
This time I actually learned something, or in more pleasant words: I was reminded that there was something about floating power supplies, measuring voltages and something called ‘common ground’. Only I don’t remember ever being taught that it can hurt too.
Here’s what I did:
I plugged an [...]

robert Electronics., Fix me. ,

Jyetech AVR digital oscilloscope DIY KIT — trying to fix it – part 2

August 9th, 2009

Maybe you remember my last post about the Jyetech oscilloscope and it’s weird behaviour. Not all of them are strange, as the free replacement DIY KIT I received from them works fine. At that time I suspected a sick ATmega64 cpu and had all sorts of plans to detect what components might be bad.

Long story [...]

robert DIY., Electronics., Fix me. , , , , , , , ,

Note to self: 26.0V >> 2.60V — A short ChipQuik review

August 4th, 2009

Nothing good can come from a freak idea after midnight !
I was tired and should have gone to bed. But when I get too tired I can’t fall asleep anymore and turn into a zombie, looking for something stupid to do. Sadly at that time my idea seemed brilliant.
So I started testing how low [...]

robert Arduino., Electronics., Fix me., PCBs 'n stuff. , , , ,

Jyetech AVR digital oscilloscope DIY KIT — trying to fix it – part 1

July 12th, 2009

The symptoms since a firmware upgrade (and downgrades, re-upgrades…):

strange characters on the display for SEC/DIV
system freezes
+/- buttons are ignored (but still work physically)
the ADC chip doesn’t get a CLK signal during a freeze

My theory:
The ATmega64-16AU is overclocked to 20MHz, which is a good reason for failure. But all the other KITs seem to work, so [...]

robert DIY., Electronics., Fix me. , , , ,

Jyetech AVR digital oscilloscope DIY KIT — Firmware upgrade odyssey

July 9th, 2009

I bought the DIY KIT at seeedstudio recently, as I needed to feed my soldering obsession. Here are some images of the KIT coming right out of the box:

I had to use my milling machine, because the front panel cutout for the LCD was too small. Oh and DON’T [...]

robert DIY., Electronics., Fix me. , , , ,