Electrical Issue: PIC input false triggering, Signal Noise suspected.

[abecker]

LinkM,

Thanks for the great circuit sketch! I don't have any inductors on hand but if this works well, I would consider making a module of it for future uses of the reed switch as a sensor.

I have an application question and to help explain it I have attached a schematic of my board. My traces on the etched board follow the lines on the schematic literally. You will observe that at PIC pins C4-C6 my three sensors are pulled up with 4.7k resistors to 5vDC. At the same connector I have a ground pin which further down the line combines the 3 grounds from the switches.

My question is: Would it be good or bad practice to place the inductors further away outside the controller enclosure say under the table? This would necessitate for each of the 3 signal wires a length of lead wire maybe 6-12 inches away from the board itself (am I just creating another albeit shorter antenna?) The control enclosure is already pretty filled with stuff but maybe I could still fasten a daughter-board to take care of this function. I would really hate to redesign and rebuild my present main board yet again to integrate the inductors.

Lastly since I am new to working with inductors could you spec or describe what I would be looking for number-wise from say the Digi-Key online catalog?

Thanks.