Currently working on a project where the idea is to read temperatures from multiple DS18B20 connected to a Fio. These readings are sent by xbee to a Arduino ethernet and then to pachube/cosm.
I have soldered an audio-jack (female) connector to the Fio with the V to the battery, data line to digital pin 7,ground to digital pin 8 and a 4k7 pull-up between V and data.
For the temperature sensors, I have soldered these into audio-jack plugs, and the idea is to use regular jack cables and audio splitters(see below) to be able to expand the network of sensors to the number and locations wanted.
The setup currently works fine with one splitter and two sensors(on a 1 meter cable each) connected to the board this way. My problem is when I try to add additional sensors, or longer cable length. The problem is then that no sensors seems to be present.
According to the data sheet of the DS18b20 it should be possible to achieve substantial cable length and number of devices.
My experience in electronic components/design is very limited
som hoping some of you might be able to give me some guidance
1: The fio provides 3.3v while the data sheet states a range of 3 - 5.5v. Could it be that 3.3v is sufficient for a few sensors, but not for a larger number?
2: I chose the audio jack cables/connectors due to ease of supply if wanting to expand cable length.
Any reason for this cable not being a good solution?
3: Any other idea of what might be wrong?
In advance, thanks alot for any help!