Communications with multiple RS232 devices

Hi all,

I have a piece of equipment that communicates to a PC over an RS232 connection.

I want to be able to monitor the data being sent, by using an Arduino inline with the existing systems.

I’m currently planning to use an Arduino Mega, as it has sufficient processing power, and has 4 UART connections. I have also understood that I will need to use a chip such as the MAX232 to convert from RS232 to TTL.

My question…
I can see that the MAX232 is ‘dual driver’… does this mean that I could use it for converting RS232-TTL as well as TTL-RS232 or would I require a separate MAX232 for each connection?

Thanks in advance,
Tom

There are several types of MAX232 chip but if your referring to this one then yes it has 2x TX & 2x RX ports so you could use just the one chip to allow the Mega to sit in the comms line to pass serial data between ports and copy to the PC over the USB line. All assuming it's simple serial without hardware handshaking.

Thanks very much for the reply Riva.

Yes, that's the one I was looking at. The equipment is for marine survey, but does use a very basic serial connection.

I had planned to use it as Sensor>COM1>Mega>COM2>PC as opposed to the way you described but sounds like this should work too.
My plan is to use the Mega to display the serial data on an LCD, thus avoiding the need for having a laptop/PC. For some reason laptops don't seem to fare too well on the back deck of a ship!!

twchambers:
Thanks very much for the reply Riva.

Yes, that's the one I was looking at. The equipment is for marine survey, but does use a very basic serial connection.

I had planned to use it as Sensor>COM1>Mega>COM2>PC as opposed to the way you described but sounds like this should work too.
My plan is to use the Mega to display the serial data on an LCD, thus avoiding the need for having a laptop/PC. For some reason laptops don't seem to fare too well on the back deck of a ship!!

The existing Serial library DOES NOT provide any flow control. so you are going to have to bypass the RTS/CTS around the Mega if the devices use hardware flow control and keep the latency down. Or just keep the latency down if the devices use Xon/Xoff flow control.

Chuck.