How long?
12 meters
No, maybe 25cm at most.
But, its just a digital signal right, so what would be the problem with long wires?
Short answer: The outputs of the HC4051 were not designed to drive cables/wires.
The Long answer will be long.
Also, that sensor uses a pseudo-I2C bus
Should have mentioned 12 meters in your first post 17 days ago.
A solution will be complicated.
Wire has resistance.
Wire has capacitance.
Those form a low-pass filter, attenuating higher frequencies..
The longer the wire, the more of each.
Sorry about that.
I was unaware about this potential issue.
Get data from the sensors, most of the time, so i will just use the data i can.
Thank you for the help
Maybe but it may be corrupted, how do you know if it's valid?
True I can't.
But from what is can see when comparing the different sensors, on different wire leghts. The measurements are either way or pretty similar.
Well from this point on it's your call.
I will test this for now, but do you have a suggestion on a solution to this issue.
Could i be possible to connect individual arduinios to each sensor and log data from them at the same time?
you could have a "local" arduino at each sensor and then those arduinos could be on a RS-485 bus to report the data to a master arduino somewhere.
There are ready made modules for this transmission
and 12m is short distance for this technology.
Thanks, that is good to know.
That's one solution and probably the "simplist" but you will need 7 Arduinos total. How to connect them to the main Arduino will depend on how the sensors are arranged.
Are they all 12 meters from a central point or in a row?
Maybe draw a simple diagram to show the arrangement.
So the two end sensors will be 6 meters from the central Arduino, is that correct?
Yes, on the drawing there is 7, but that is not the case anymore.
do you expect the lux value to be significantly different 6 meters apart? Do you have trees or obstacles in front of some?
So only 6 correct?
I have to ask, what's your definition of "at the same time" - will a data skew per sample of 1ms, or 10 ms for that matter, have any impact for you? I ask, because an RS485 network will require polling of the individual devices sequentially, so the data is not "at the same time".
And, further to that, how will you deal with synchronizing all Arduinos so that the data is sampled "at the same time"?