Hi I just got my micro all in one 4.1 boards. Wow great boards. I am wanting to hook up a 0.5-4.5v pressure sensor instead of the 0-20ma, can see a jumper for 0-20ma on the board can I use it as is if I leave that off? I’m trying to trace traces but have not got far yet.
For 0-5V sensor you don’t put a jumper on the “0-20ma” header, only one on the 3 pins header on the “pressure” side.
The “0-20 ma” jumper connect an extra resistor that make a current consumption up to 20 ma which is not needed/ not desirable for a 0-5v sensor.
Ok thanks. I will have to do more testing. This is the schematic I was looking at. I applied 5v to the circuit and tested the teensy pin but I was getting erratic results. I will have to test someone.
the voltage at Teensy pin should be around 2/3 of input from 0 to about 4.5 V then should be around the same because of the zener diode.
If you have to read precisely up to 5V you could add a 2k thc resistor at R58 or remove R56 and add a 2k to R57 to make 1:2 reading at the Teensy.