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Topic: Dumping firmware/software...and/or reflashing?? (Read 27 times) previous topic - next topic

mikedehaan

If you put the negative multimeter lead on the negative battery terminal, and the positive multimeter lead on the GND pin of the chip on the board, I would think the multimeter would show continuity.

I'll try this at home tonight and let you know if it works for me.

Coding Badly

Know whats weird?? I got out my multimeter and put it on the continuity test mode and tried it on all pins (started with the pins you defined as VCC and gnd) and I didn't get any continuity? Shouldnt it be beeping???


Don't do that!  It violates the electrical specifications.  While very unlikely in this case, any time the electrical specifications are violated there is a possibility of damage.

mikedehaan

Wow, good catch.  I didn't think of that.  The multimeter is probably sending some voltage through to get from point A to B that might cause damage.  What about measuring Ohm's?  Would that do the same?

bag06a


If you put the negative multimeter lead on the negative battery terminal, and the positive multimeter lead on the GND pin of the chip on the board, I would think the multimeter would show continuity.

I'll try this at home tonight and let you know if it works for me.


Confirmed-- Negative terminal to Pin14 worked for continuity.

Coding Badly -- TY for the warning....I certainly dont want to fry my chip :-\. How does it violate specifications? Is it possibly sending to much current and/or voltage through the chip just with the batteries in the multimeter?

Coding Badly

Quote
Absolute Maximum Ratings*
...
Voltage on any Pin except RESET
with respect to Ground ................................-0.5V to VCC + 0.5V

*NOTICE: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.


VCC with respect to GND is zero.  The continuity and ohm meters very likely operate outside the -0.5 to +0.5 volt range.

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