H
Henrik [6650]
- Jan 1, 1970
- 0
Hello group,
I am trying to simulate a logaritmic trimpot in software on a small
microcontroller.
We have some industrial controllers where some parameters (i.e. max running
time) is set via potmeters on the front. And one of the potmeters are
logaritmic to give a finer change in the lower area and a more coarse change
in the high area.
My idea is to use a linear trimpot (which we have stocked) to replace a
logaritmic pot (which we have not stocked). The pot wiper is connected
directly to the micros internal AD converter and to GND/AVCC of the
microcontroller. By turning the pot I can now measure 0-1023 (10-bit AD) on
the micro, that is just fine.
I need to convert this 0-1023 value to a value between 10 and 54000
logaritmic. I think a mathematical function or a table lookup is the way to
go, but I actually cannot figure out how. I think mainly due to my lack of
knowledge about how such a pot actually works.
So any help is gladly appreciated.
Thanking you all in advance.
Best regards
Henrik
I am trying to simulate a logaritmic trimpot in software on a small
microcontroller.
We have some industrial controllers where some parameters (i.e. max running
time) is set via potmeters on the front. And one of the potmeters are
logaritmic to give a finer change in the lower area and a more coarse change
in the high area.
My idea is to use a linear trimpot (which we have stocked) to replace a
logaritmic pot (which we have not stocked). The pot wiper is connected
directly to the micros internal AD converter and to GND/AVCC of the
microcontroller. By turning the pot I can now measure 0-1023 (10-bit AD) on
the micro, that is just fine.
I need to convert this 0-1023 value to a value between 10 and 54000
logaritmic. I think a mathematical function or a table lookup is the way to
go, but I actually cannot figure out how. I think mainly due to my lack of
knowledge about how such a pot actually works.
So any help is gladly appreciated.
Thanking you all in advance.
Best regards
Henrik