Multiple pressure sensors problem

Hey guys,

I'm using 4 pressure sensors (FSRs) with my Arduino UNO. For some reason, when I push in on one of the sensors, there is a tiny bit of pressure detected by the other sensors.

For example if sensor 1 is reading a value of 40, sensors 2, 3, and 4 are all reading a value of ~4. And if I push down on sensor1 harder, the value goes up on the other ones too, but by a small amount. Physically, they are not inter-connected in any way.

Is there an obvious reason for this? I've connected them up as normal, i.e. like this: http://bildr.org/2012/11/force-sensitive-resistor-arduino/ But with 1k resistors, because I need them fairly sensitive.

Thanks.

Using 1k makes it less sensitive.

When the hardware is designed well, the other channels should not get a higher value. There are a few possibilities:

Do you use usb power ? In that case the 5V is not a stable 5V.

Pressing on it with your finger introduces noise (for examples from the 50Hz/60Hz mains) to the circuit, that could easily cause it.

Draw a schematic on paper, photograph it, show it to me. 4 sensors, 4 resistors, 4 analog inputs?