AI conversion

[CKB]

Hi,

Another time I stumble over the AI input and issues with reading 0-10V signals with the unipi1 and Mervis.
Is there any FAQ on this because I couldn’t find an FAQ or exemplary project with Mervis and the old unipi1 (but only with neuron, axion etc…) ?
The reason I ask is the conversion linear by two points. I just replaced my old brightness sensor by a new one which makes me rethink the conversion I am currently using -
X1 0
X2 115000
Y1 0
Y2 100

Where do these 115000 come from. Or better question - what is the correct conversion to transform a 0-10V signal to 0-100% with Mervis and unipi1??

Many thanks&
Regards
CKB

[AVsetula]

Hi,

The best way to calibrate the AI on the Unipi 1.1 is to turn off the transformation for the AI, connect a voltage source with an output of exactly 10 VDC and look at the value on the AI in the Mervis IDE. Remember this value and then insert it as parameter X2 in the two-point linear transformation.

Set parameter Y2 to 10 if you want to get the voltage value directly, or set to 100 if you want to get the percentage value [%].

Set both parameters X1 and Y1 to 0.

In the attached picture you can be inspired by the settings for my Unipi 1.1.

Have a nice day
Regards

Antonín Všetula,
Technican