UART on Minnowboard

Szymon Janc <ext.szymon.janc@...>


I have a problem with minnowboard and it's uart (I use btshell sample for
testing and trying to communicate with Bluetooth module using H5 protocol).

The problem is, that there is no transmission on the TX pin of the minnowboard
(checked with logic analyzer) and no matter if the bt module is connected or
not. What is more, the console uart is working perfectly.

I was connecting CTS/RTS pins to module, or to ground, or to nothing in
different configurations - no effect.
Changed supporting of flow control in UEFI - no effect.
Also tried changing UART_1 address and IRQ in Zephyr Kconfig to:
- Port: 0x02f8, IRQ: 3
- Port: 0x03e8, IRQ: 4
- Port: 0x02e8, IRQ: 3
And also no effect.

Minnowboard isn't broken or something, all uarts work with Ubuntu, and almost
all with Fedora (couldn't open only UART1, rest was fine). BT modules are also
fine, they work on minnowboard with ftdi usb/serial converter with Fedora and

Any advise on getting UART_1 working with zephyr?

Szymon Janc