Hi,

I have a requirement where i need the carambola to connect and talk to another MCU using UART.

The carambola 2 (using ar9331 soc) seems to have only one UART which is used for serial console access and by the bootloader. The problem is i cannot send anything unwanted to the serial lines even during the bootup process and also once the openwrt starts. In short the UART has to be completely silent unless used by the application. Also seems like the software UART implementation using GPIO cannot achive higher baudrates (i am looking for baudrate > 115200). Is there a possible way to achieve this in AR9331 (completely disable the Serial UART) and for bootloader use the modified webgui enabled uboot. If this is possible how easy is it to acheive it.

Also I hope that i could use the second UART of carambola (using RT3050) in the openwrt. does the stock openwrt for carambola has the second UART enabled by default.

Can you explain in a bit more detail how you succeded completely silencing serial console? This is awesome!

Why not use a SPI or I2C UART chip like the one from Maxim?

I saw some sporadic mentions that some people got uart0 to work on Carambola 2, while leaving default uart1 for console.
Does anybody have more info how to enable uart0 on Carambola 2? Having two uarts on Carambola 2 would be awesome!

Update: I see my mistake, people that are talking about using uart0 (second uart) are using Carambola 1 and I thought that they also have Carambola 2 as I do. Ufff, I really would like to have two uarts on Carambola 2.

Not a true solution, but if you badly need a second UART on Carambola2, you can use USB to COM adapter.