Hi,
First of all, i have connected all the pins which illustrated with GND above in the body of this page to common ground, as i re-drew below
and as you mentioned, poor wire connection may be the part of cause of noise.
As i replace pin head wire with shorter jumper wire, signal became stable, especially, when wire for IN+ PIN is replaced. So, i am soldering with shield and finally will draw pcb design for this.
Unfortunately, because of my poor knowledge for electronics, I can not fully understand isolation of ground.
I think that separating ground you are saying may be like picture below
(Staying Well Grounded | Analog Devices)
Anyway, I have to learn more about ground separation, and your advice that loads of
superfluous little wire antenna pick up noise is right.
thanks a lot, you have saved my one week. I should have to met you faster
I appreciate it, have a beautiful day
