Question about external USB host to Serial

Using Arduino Project Guidance
1

Hello
I am new using arduino.
I am doing a project, and I need use the USB port included in arduino Mega for receive information, and send this information to other arduino Mega using Serial communication. In other words, I need use one arduino shield like a bridge.
I have searched online and I think that I need an USB host like this:

or this

https://www.circuitsathome.com/products-page/arduino-shields/usb-host-shield-for-arduino-pro-mini/

But I am not sure if it possible, if I need exactly this Host or other one and how do that.
I need your help please.

Thanks previously for your help

2

What you need will probably depend on what USB device you want to connect to your Arduino MEGA.

3

You can connect one Mega to another using Serial without needing any USB stuff.

Use USB to connect to the PC and use serial to serial between the Megas

...R

4

But I can't do that, because I can't access to the other arduino Mega,this is part of a machine.
I have done a program in PC which permit me connect with the machine (arduino mega inside) using Serial communication. But I need now connect other board (mega too) with the pc for control some motors and connect this board with the board inside the machine like if it was the PC.
In other words, I send information to the first board, if is information about machine control, this one send this information to the other board, on the other, hand if is information about motor control this board use that.
Now I have programed all motor control and communication with the PC, I only need communicate with the other board like a PC ( using serial communication).
I have seen a board, Arduino Mega ADK, which has a USB HOST. You think that I can use this one??

5

Sorry, but I don't understand Reply #3.

This crude diagram illsutrates what I have in mind. If it is not suitable please provide a diagram that illustrates what you need.

PC ------USB cable------MegaA MegaB
| |
Serial1 Serial1

What do you mean by "I can't access to the other arduino Mega" and which Mega can you not access ?
If you can't access it, how can you put a Host shield on it?
Can a Host shield recognize a Mega?

Could you connect both Mega's to the PC and use the PC as the bridge.

...R

6

Ok sorry, I need the next configuration:

PC --------------USB cable-----------------MegaA---------------USB cable----------------MegaB
(serial communication) | | (serial communication)
| |
| |
| |
| |
Motor 1--- ---Motor 2

I have now solved the blue part.

And the black part, I have done PC------------------USB cable------------------MegaB
(serial communication)
But I need do that like the first schematic.

I don't have access to the MegaB because this is inside a machine, I can't access to its pines, I need connect to it by USB Cable.

7

That diagram cannot work because you cannot take a TEE off a USB cable to control motors (or anything else) - but that may just be a problem with your diagram.

I can see now that you are hoping that you can send serial data to MegaA and have it communicate with MegaB using a USB Host shield. I'm afraid I have no idea whether that is possible - but I'm sure others will know.

...R