RF problem with limit switch and estop

[Mkroe]

Hi All,

This may have been discussed before not sure couldn't find it here using search.

I have been plagued with RF spikes triggering my limit switch and Estop. Tried the debounce to no avail. Using well shielded cables did not improve this either.

I live in an area where I am in the flight path of a major airport, It may be the planes radio causing this? No Matter though



After scoping this, we saw unusual spikes that were giving phantom triggers.

Solution is easy and cheap.

Using a 0.1 Uf /mfd film type capacitor , NOT ELECTROLYTIC

Bridge each set of wires at your breakout board with a cap. One lead to ground the other to +V.

This will act as an Rf filter and should eliminate the problem. You may need to add a second one parallel to this but most likely not.

I have since run a few million lines of code and no hiccups since this modification.

Just an FYI if your having this problem.

MK

[Mkroe]

AH HA! I found my Phantom RF spike. I was getting a static discharge from the vacuum hose when it touched the frame usually somewhere in mid table area. The hose may touch the upper gantry at various stages of XYZ location. The ground wire was broken for this hose.

I'll leave the caps on though.

Mike