1-Wire Network

[Pete]

Great news khalid!

[JeffCharger]

That's great! Make sure to plan your setup for 50 devices to reduce the possibility of problems. With 50 devices you probably don't want a star topology. Do some reading on suggestions on designs...

[khalid]

Thanks Pete and Jeffcharger
Actually i've planned to use hobby board master hub for supplying external power n also to avoid data loss due to many sensors on the net
One thing that is ticking my mind that i used DS18B20 not DS18B20-PAR with vdd and gnd connected..for DS18B20-PAR are vdd n Gnd internally connected in the sensor?

[Pete]

The drawings on the DS18B20-PAR show no connection internally for it to be in parasitic mode.

[Michael McSharry]

for DS18B20-PAR are vdd n Gnd internally connected in the sensor?

Yes and they disconnect the vdd from the external pin to avoid any misuse. It makes wiring the devices easier if you never want the abilty to power them externally.

It is my understanding that when using parasitic power it is possible to only do one A/D conversion on a 1-wire network at a time and each sensor will need about 1 second to do the conversion. If you do you own low level interface software and have external power then it should be possible to command all devices to start conversion and then 1 second later read the result of all sensors. My xapmcs1wire is a general purpose application so it does one sensor conversion at a time so it does not matter which type of connection is made.

[khalid]

Yeah i got it...sometimes things get puzzled when u go through so many documents :P
When logging temperature in one wire viewer it displays the temperature of only selected device and when u click the other device the data for the previous device disappears..Any other software that can be use along one wire viewer as I have installed Logtemp ,but I dun know Logtemp works with it and it also saves the data after every 30 sec and I want to log data atleast after every sec...any other good logging software..?
Same issue with hobby board master hub, that it cant display the data of all channels at the same time

[khalid]

n I also want an csv excel file or text file to export data...n i also have to keep master hub in mind as i wil be using star topology to connect 50 60 sensors and also have to log data continuously from all six channels..One more thing about maxim, they say that when u buy more than 25 to 99 DS18B20+ u will charged around 3.99$ per part but when i enter the quantity 50 they charge me alike for 300$..damn its too costly..any other forum from where i can get cheaper n reliable sensors

[Michael McSharry]

You need to set reasonable expectations for you project and you should start with a small environment rather than you final objective. As I indicated before you can expect about 1 second per sensor so to read 50 sensors it will be 50 seconds. You are now expanding to using a hub so you have switching logic to talk to hub as well. If you are able to record a set of data every minute then consider how much data you will be collecting and the duration you will be able to run with available memory.

You are in the Ultra1Wire plugin forum so the expectation is that you will be using Homeseer to collect data using the plugin provided by UltraJones. To my knowledge this plugin does not support the DS9097U, but uses the EDS and Temp08 interfaces.

If you really need to collect 50 samples every second then you will be writing custom software based upon the DallasSemiconductor datasheets for the 1-wire devices in you system. This is not a small endeavour.

[khalid]

Yeah I know its something to achieve..but if i want to sample after every 5 seconds then I think things would be much better...as u said that homeseer provided by ultrajones doesnt works with 9097u but what about LogTemp, digitemp....digitemp is mostly used with Linux but it has a windows based version as well..i dun know that will it work with it...any suggestions would be really appreciated