hi
i have project to connect two PT100 temp sensors , one will measure the air temp and the second will be cover with wet sleeve and measure the temp in 100% /
from that i need to calculate the relative humidity and send the calculated value in analog output 4-20mA
the formula to calculate the relative humidity from the two measured temp is below .
can some-one help with the software and the hardware connection for PT100 and 4-20mA output
Most people use a load resistor to convert 4-20 mA output to voltage, for input to the Arduino.
For a 5V Arduino, 250 Ohms converts that range to 1.0 to 5.0V.
Or, 50 Ohms converts to 1.0V maximum, which is great if you use a 1.1V ADC reference, for example.
Do you have more parts? Such as
Sounds like @yehoshua wants the opposite of that:
I can share this much with you. The Arduino will not give you a 4 to 20 mA current output and it won't give you an analog voltage output. There are work arounds but just an Arduino will not give an analog voltage or current out. Just for example a module like this will convert PWM to a voltage. You can also find a 12 bit DAC module using the MCP4725 chip. There are also voltage to current modules available.
Ron
You would need to know the compliance of the receiver for that interface.
For example if it uses a 1k resistance then you would need a supply of more than 20 volts.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.