How to USE the GND on DEVKIT_MPC5748G

[Elsa_24]

Hi, I am trying to write a program to measure the voltage across an analogue input using the ADC. My question is how to use the GND. For example I want to connect the analogue input to GND so that the result shows 0. In the part "1.2 Understanding the Header/Pinout" of the "Get Started with the DEVKIT-MPC5748G" I see for example that Pin "J12-12" is a GND. Do I have to activate this pin in the "Pin_Mux" to have this GND function? If yes, as input or output? Thanks

[jamesmurray]

Jumper wire is your answer.

[jamesmurray · Accepted solution]

I don't have experience with that exact board, but it seems you are over-thinking this.

On other PPC parts at least, there's no real MUX option on the analogue inputs - you use them or you don't.

What are you trying to achieve by measuring ground? You know from the way the ADC works that if you measure a voltage that has the same potential as the analogue ground reference, you will get zero.

The normal way to connect something on an eval board is with a jumper wire.

James

[Elsa_24]

Hello James and thank you for your answer.

In fact I was asked to write a program to measure the voltage across an active analog input and to test that by connecting this input to GND that the displayed value is 0.