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Topic: multiplexing with 4051 (Read 1 time) previous topic - next topic

rangua

hi, i'm using the 4051 for the first time. i want to expand the analog ports in the arduino through it so i can read multiple sensors.
The problem is, when i try it out on the breadboard, i either get all pins showing some nonzero value or all of them at 0.

I'm connecting the common output to the analog A0 on the arduino and to GND through a 15k resistor. On the other side, I have a potentiometer connecting the 5v rail to the pin 2 (the number of the input, not the actual pin 2) of the 4051. Vss Vee and E are connected to GND and Vdd to 5v.

what am i doing wrong? is it possible that the breadboard capacitance is interfering with the measurements?
thanks

ps. the image shows how im connecting the sensors without the power or the enable/Vss/Vee pins which are connected to 5v and GND respectively.

Grumpy_Mike

Do not use any resistors.
Any unused inputs should be connected to ground.

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