Hi!
Noob here as well as in electronics in general. (so use small words
)
As a first project with my Raspberry Pi 3, I wanted to build a multiple temperature sensor device for remote sensing a number of locations. Having poured over the interwebz and youtubez, I was successfully able to read multiple sensors on my breadboard. Cool so far. So the next step was to attach the sensors to a 10 foot long length of wire to simulate "remoteness". I wired, soldered and shrink tubed 5 sensors to 10 feet of wire each (don't have the specs handy at the moment, but should be able to get it if deemed important). Then I connected each red, yellow and black (3.3v, one-wire, GRD) to each other (crimped, solders and shrink tubed) at the other end, with a red, yellow and black lead so I can plug it in to the breadboard. All good - I can read all five sensors just fine. I next build another set of 5 wires, this time with 20 feet of wire per sensor. That worked out just fine. I can read all sensors.
If it helps, this video is basically how I have the breadboard wired up:
(two minutes in)
The problem comes in when I try to connect both sets of wires to the breadboard. Mostly, I can't read any sensors when both sets of sensors are plugged in. If I take one set of wires off the breadboard and insert more sensors directly on the board, I can read the 5 wire bundle and the other sensors (up to an additional 4 for a total of 9 sensors).
Can anyone explain why I can't seem to read the two sets together? I've been pouring over videos and forums trying to figure this out, but my extreme beginnerness is showing through.
Some forums seem to think that the one-wire protocol doesn't like star configurations (I'm assuming that's what I have, no?), but no explanation as to why. Timing?
Is perhaps the total lengths of wire creating issues? Perhaps because one set is 10' long and the other 20'? Any other insights would be welcome and appreciated.