MKR485 Shield and Modbus

Hello comrades, I recently received two MKR 485 shields for modbus RS485 serial communication (RTU) between my Raspberry Pi (Model 3 B +) and an arduino (NANO). What I would like to know is where the pins are located for communication on these shields (those where I send data as well as those which manage transmission and reception). On several forums and projects I saw that the main ports used are RE / DE anisi that RO / DI ... problem is that I would not be located these pins on the shield although RE would be on A5 and DE on A6 but RO and DI I do not see them unless it is the pins stamped Rx / Tx but to confirm to me: o ...

for additional info:
I use minimalmodbus to send data from the 7th pin (GPIO4) of the Rpi. The shield is not recognized by the Rpi when I try my program which only sends 1 or 0 to light up led 13 of the arduino.
For the nano I use the library: Modbus-Master-Slave-for-Arduino-master

There you go, I hope I was clear, if you want more details or any suggestion, don't hesitate :).
Thank you and stay safe.

The pinout is on the Arduino website here. Look in the documentation section for the schematic in pdf format.

Hello comrades, I recently received two MKR 485 shields for modbus RS485 serial communication (RTU) between my Raspberry Pi (Model 3 B +) and an arduino (NANO).

This shield is not suited for the Nano as it operates on 5V while the MKR485 shield is designed for the MKR series of Arduinos which all operate on 3.3V (ARM based).

On several forums and projects I saw that the main ports used are RE / DE anisi that RO / DI ... problem is that I would not be located these pins on the shield although RE would be on A5 and DE on A6 but RO and DI I do not see them unless it is the pins stamped Rx / Tx but to confirm to me: o ...

The shield has documentation and freely available schematics. DI is connected to TX (14) while RO is connected to RX (13).

The shield is not recognized by the Rpi when I try my program which only sends 1 or 0 to light up led 13 of the arduino.

Recognized? How do you think should the Raspberry Pi recognize the shield? The shield is designed for an Arduino but even an Arduino cannot "recognize" the shield.

pylon:
This shield is not suited for the Nano as it operates on 5V while the MKR485 shield is designed for the MKR series of Arduinos which all operate on 3.3V (ARM based).

The shield has documentation and freely available schematics. DI is connected to TX (14) while RO is connected to RX (13).

Recognized? How do you think should the Raspberry Pi recognize the shield? The shield is designed for an Arduino but even an Arduino cannot "recognize" the shield.

Hello, thank you for your answer! Are you really sure that it is only suited for MKR series?Why? there are all the O/I and the MAX 3157 to make it work ? So I should go for RS-485 Module like this one : https://www.amazon.ca/MAX485-RS485-Converter-Module-Arduino/dp/B00INWXPHM

Are you really sure that it is only suited for MKR series?Why? there are all the O/I and the MAX 3157 to make it work ?

I wrote what the problem is: the interface voltage. Yes, I'm sure the module is only suited for a 3.3V device and the Nano runs on 5V.

So I should go for RS-485 Module like this one : https://www.amazon.ca/MAX485-RS485-Converter-Module-Arduino/dp/B00INWXPHM

That may be an option.

I am not an expert--just barely getting into the Arduino arena. My hardware skills are poor (I had another person doing the hardware side when I was a programmer) and I last programmed in Pascal!

However... I DID manage to figure out how to wire up a MKR Canbus Shield to an Uno using the Uno's 3.3v pin. And it works!

I just posted the info here:

Maybe it will help.

However... I DID manage to figure out how to wire up a MKR Canbus Shield to an Uno using the Uno's 3.3v pin. And it works!

A CANbus shield is not the same as a RS485 shield!

pylon:
A CANbus shield is not the same as a RS485 shield!

Yes, but I was able to use the 3.3v pin on the Uno to power the MKR board. That was my point (poorly made, I guess).

I don't have a Nano--maybe there's not a similar 3.3v power pin on the Nano?

Yes, but I was able to use the 3.3v pin on the Uno to power the MKR board. That was my point (poorly made, I guess).

In most such cases the powering of the board is the smallest problem. Usually you have to use a level converter to adapt the 5V to the 3.3V and vice-versa because the low voltage device is not 5V tolerant.