MKR 485 function of RE & DE? free up pins A5 & A6?

Hardware MKR Family MKR SHIELDS
1

I have a MKR 485 connected to a MKR Wifi 1010.
I use the MKR 485 to communicate via modbus with an energy meter.

I would also like to connect analog current meters to the analog inputs A0-A6.
However, A5 en A6 seem to be used by the MKR 485 for 'RE' & 'DE'.

What is the function of RE & DE?
Are these used actively in the modbus communication?
Is there any way I could free up the pins A5 & A6 to be used as analog inputs ?

Thanks in advance!

2

RE enables the receiver output of the line driver so you can receive data. DE enables the transmitter side of the line driver so you can send data.

Yes. They are used all the time when sending and receiving messages.

Not without some surgery to your MKR485 board and tweaks to the library.

3

Hey Mark,

thanks for your quick reply!
Your answers were all very clear!
Much appreciated !

4

@madhondt You may wish to look at analog multiplexers instead, to allow you to bring many signals in to one analog input using a couple of digital outputs as selectors. An item like this, on Amazon:
image

5

@camsysca

Yes, that seems like a promising option to solve my problem. I will definitely look into this!

Thanks !

6

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