EDIT: Sorry- I resolved the issue, made a CAT-5 cable and changed the pairs around in the RJ45 to pair each signal with a ground or 5v0 line and the issue dissapeared. Wasn't able to see any voltage fluctuations on my o-scope but i guess something was still happening with crosstalk
Hey everybody. I have a circuit using 2 LM393 Dual Differential Comparators as shown in my schematic. My problem is that there seems to be some interference issues in my circuit. Each input is setup on a hall effect flow sensor, and only reach about 30hz square maximum.
In trouble shooting iv'e checked:
Also it's not noted on the schematic but the input is a squarewave 0v0 - 5v0. The signal is carried over a CAT-5 cable that in honesty isn't optimal as a twisted pair is carrying 2 signals(however, not the signals that are having correlation with each other) And with the oscilioscope i don't see much reason to suspect cross-talk especially as the fastest the sensors transmit in my application is roughly 30-40hz.
Hey everybody. I have a circuit using 2 LM393 Dual Differential Comparators as shown in my schematic. My problem is that there seems to be some interference issues in my circuit. Each input is setup on a hall effect flow sensor, and only reach about 30hz square maximum.
- When Input 1 of a comparator is High and the second input oscillates then both outputs oscillate causing the microcontroller to show that water is flowing through both sensors instead of just #2.
- Same happens vice versa is Input 2 is high and the first input oscillates then both outputs oscillate .
- Very little happens if one input is low and the second oscillates, occasional noise but the software easily filters this out.
In trouble shooting iv'e checked:
- impedance between all inputs and outputs and find them all to be within the expected impedance's.
- Ive used my oscilloscope to see if the problem was on the inputs, however; voltage stays steady to within a couple millivolts on the steady input while it's output is oscillating along with the second input.
Also it's not noted on the schematic but the input is a squarewave 0v0 - 5v0. The signal is carried over a CAT-5 cable that in honesty isn't optimal as a twisted pair is carrying 2 signals(however, not the signals that are having correlation with each other) And with the oscilioscope i don't see much reason to suspect cross-talk especially as the fastest the sensors transmit in my application is roughly 30-40hz.
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