Maximum USB and UART port that can be handled by a µP A20

[ramoneb]

Hi,
I am designing a card and I need too many UART out put to handle all my external sensors.

I am using a Pcduino3 (A20). I used a USB HUB (with 7 USB port) then a FT4232H to have 4 UART for each USB.

I need 4 other UART so If I add another FT4232H to have more UART, can it cause any problem for my µP ?

In the end I will have : 7 USB PORT . 2 of this seven port will be connected to two of FT4232H to have 8 UART in total.

Thank you

 

[barry]

Your question is unanswerable. "Can it cause any problem from my uP?" What's your data rate? What else is the uP doing? If you are running 300 baud and you send one byte to a UART once a day and the uP has no other tasks, then you probably won't have any problems. If you are running 115K baud and you are sending data continuously to every UART and your uP is calculating PI to the 1,000,000 place, then maybe you will have a problem.

 

[ramoneb]

Hi barry,
Thank you for your question. I didn't ask for problem related to computing load or baud rate. My question was about the maximum number of device that can be connected to µP. In theory the number is 127 devices that we can plug-in and still detect... but I am not sure what is this number in practice.

Thank you anyway Barry.

 

[andre_luis]

In the end I will have : 7 USB PORT . 2 of this seven port will be connected to two of FT4232H to have 8 UART in total

The HUB ports used just to forward connections are not considered as devices.