K8055 analog inputs - temp with IR, low mA range signal

Hi all,

I am working on a project to automatically measure temperatures remotely with an infrared sensor.

The current sensor (and its electronics) works perfectly showing 1mA per °C for the range of temperatures needed on the multimeter.

How can I get this weak signal measured on the K8055 analog inputs?
I have the software ready but do not get any readings if I connect the signal directly to the K8055 A1/A2 - even after adjusting R8/R9 resistors to adjust the gain of the ports.

As I am not really familiar with electronics I could use some hints and advice …

Regards
Adrian

Edit:

  • I just tried some higher voltage to the ports as a test - cannot get a reading with 2.8V.
  • I get readings when in simulation mode (SK2/SK3) and adjusting RV1 and RV2 though.

Maybe it’s the inputs that are broken? How could I repair/test that?

It seems that your infrared sensor outputs current.
The K8055 input has to be voltage.
To convert the current to voltage you have to add proper value of a resistor between the analog input (A1) and GND.

Oops my fault - it’s 1mV per degree not 1mA.

Meanwhile I finally found the issue - I can read but I was too dumb to understand what RV1/2 were made for … now I can trim the signal as needed. :oops:

OK. Nice that it is now working fine!