rpi inputs "too sensetive"

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rpi inputs "too sensetive"

Postby nullx8 » Wed Jan 29, 2014 6:24 pm

this is Raspberry related .. but since the technology is almost the same ... i dare to ask here ;)

i use a pi-face bboar which triggers the inputs via null. over an 1.8Kohm Resistor ..

so all looks very straight forward. BUT the reed sensor attached to it (on a 10 meter cable) trips randomly the board.
so i tought it may be interferences or somethings since the inputs are really sensetive ...

i added a 47kohm resistor .. no luck
then i used a Relais and send 12 volt trough the reed .. the Digital wire is now shorter then 2 cm from null to input ..
still ptoblems ... added a 47kohm resistor ... still issues ..

in general if the reed is open .. everything is okay but if its closed it flips between on an of randomly.

however, every time iam NOT at home ... it works just perfectly.
so it is sure some interference from other hardware .. (but sure nothing arround there)
i changed the power source to a indipendend power suply .. still no luck ..

anyone has some experiences about this things and maybe know how to fix it ?
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Re: rpi inputs "too sensetive"

Postby raymonvdm » Wed Jan 29, 2014 9:08 pm

I have noticed someone with issues when using a normal wire for it staircase lights. When replacing the cable with a twisted pair (UTP) the problem was solved.

http://blog.hekkers.net/2014/01/06/stai ... -finished/
Last edited by raymonvdm on Wed Jan 29, 2014 9:40 pm, edited 1 time in total.
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Re: rpi inputs "too sensetive"

Postby Digit » Wed Jan 29, 2014 9:17 pm

Right! :lol:
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