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Can somebody help me about my circuit.
Problem: Even when the switches are open, I can still measure low resistance values between the terminals of my switch which is almost the same when the switches are closed. Please help.
I don't understand where you are measuring resistance. Your circuit has a switch with pull-ups and tri-state buffer which will allow you to read The switch positions. There is nowhere to sensibly measure resistance. If you power the circuit it should work.
Thanks for the reply. Ummm when i try to test the switch, it somehow looks like it is always closed[ON] even when it's open[OFF]. Is there something wrong with my connections or is it the components?
Your circuit looks fine. You cannot measure the switch resistance with all the other components connected. The closed switch should measure as a low resistance (less than one ohm) but trying to measure the open resistance will give a resistance dependant on the pull-up resistors you have used.
That assumes you are measuring resistance directly at the switch pins. You cannot measure resistance at the connector.
The open resistance i measured was around 50 ohms and the pull up resistors i used were 330 ohms. Did I measure the right open resistance value? By the way, this only occurs when the negative terminal of the multimeter is connected to the grounded pins of the switches.
The resistor value is lower than I would expect to be normally used, but you measurements are not unexpected. You will not be able to measure open resistance when in that circuit. The meter connections matter because one way round the meter turns on the IC protection diodes.
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