Why is my oscilloscope showing me this?
SRLM
Posts: 5,045
I have a simple circuit with a button, a few resistors, and a few capacitors. When I press the button I get the image shown in the oscilloscope with the RC type decay while the button is pressed and a "rebound" when it is released:
The confusing part is that I can measure at the same point with my multimeter and it's as I expect: a constant 4.2v (the battery voltage). There is no decay to 0v.
The circuit is pretty simple. The extra stuff is so that the single button can double as a power switch and an I/O input. In addition to what is shown there are several capacitors (4.7uF,
0.1uF) on the BATT bus along with a few ICs (a GPS, a MAX17048G+ battery fuel gauge, an RTC, and a MAX8819A).
I'm measuring at pin 2 of the switch. The Propeller isn't doing anything (all I/O's are input).
Edit: marked solved.
The confusing part is that I can measure at the same point with my multimeter and it's as I expect: a constant 4.2v (the battery voltage). There is no decay to 0v.
The circuit is pretty simple. The extra stuff is so that the single button can double as a power switch and an I/O input. In addition to what is shown there are several capacitors (4.7uF,
0.1uF) on the BATT bus along with a few ICs (a GPS, a MAX17048G+ battery fuel gauge, an RTC, and a MAX8819A).
I'm measuring at pin 2 of the switch. The Propeller isn't doing anything (all I/O's are input).
Edit: marked solved.
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Comments
That's the trick! Thanks!