Hello,
I have a variable voltage/frequency signal that I need to measure with my uC. My uC can accept up to 3.3v+, so I'm wondering the best way to measure this positive and negative variable voltage value, while protecting my uC. The signal will range from +/-5v to +/-10v, at various frequencies. Below are a few scopes.
I was thinking that if I used a diode to filter out the negative part of the sine wave, and then a 3.9k/5.1k resistor ladder with a 3.3v zener "teed" in between the resistor ladder out and the uC pin in.
This would give me ~ 1.75v at 5v peak and 4.03v at 10v peak, of which my uC cannot take so that is why 3.3v zener would be needed.
Thoughts? Thanks for reading.
I have a variable voltage/frequency signal that I need to measure with my uC. My uC can accept up to 3.3v+, so I'm wondering the best way to measure this positive and negative variable voltage value, while protecting my uC. The signal will range from +/-5v to +/-10v, at various frequencies. Below are a few scopes.
I was thinking that if I used a diode to filter out the negative part of the sine wave, and then a 3.9k/5.1k resistor ladder with a 3.3v zener "teed" in between the resistor ladder out and the uC pin in.
This would give me ~ 1.75v at 5v peak and 4.03v at 10v peak, of which my uC cannot take so that is why 3.3v zener would be needed.
Thoughts? Thanks for reading.
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