One wire cable length and resisteor value
5 March, 2012 - 16:55
I have moved my HAH due to multiple lock ups that i suspect rf/mains interferance from an adjacent shower pump.
now my 1 wire sensors are 30+ metres away the only way i can get them to work is to reduce the resistor value right down to 2k35 (2X4k7 in parrallel as i didnt want to unsolder the board one)
noe this is working (reliability to be determined) has anyone "played" with the resistor value and anyone know what the min value "could Be" just thinking if i add more on alonger run can i reduce resistor value further?
P.S i have read somewhere that laddering the one wires is better than star configuration, anyone got a comment?
I've run a setup that used 2K2. Seemed solid enough.
There is a good discussion here http://pdfserv.maxim-ic.com/en/an/AN4255.pdf
and of course on the 1-Wire bible here http://www.1wire.org/Files/Articles/1-Wire-Design%20Guide%20v1.0.pdf
Cheers,
Derek.