UART1 with Beta 14.07


#1

I was successfully using UART2 (using ttyHSL1) with 14.04 but I know that the console is now allocated for UART2 in 14.07. I looked in the /dev directory and I only see ttyHSL1 as listed (as I would expect ttyHSL0 to be there too), so what device should be opened to access UART1 with the new version of Legato?


#2

You can configure the UARTs on those platforms using an AT command (AT!MAPUART)

The syntax is
AT!MAPUART=a,b

a=service type
b=the UART number

In this case the service is 17 (means used for customer application)

So, AT!MAPUART=1,17 will set UART 1 to be available for application use. I hope your firmware version is recent enough to support this.

The device not showing up is beuase the hardware is controlled by the modem core (due to configuration) and so is not available to linux.

Hope that helps.


#3

That seemed to work. But is there a way I can do that from my application? I didn’t notice any Legato APIs that I could use to send AT commands to the modem. Or maybe I am just missing them?


#4

There is currently no way to do AT-commands from Legato. Actually we’re hoping you won’t need to.

Something like configuring what a UART is for would normally happen in the factory rather than being dynamic, so I’m not sure I see a case for having an API to do that. Do you have something in mind?

Regards,
Andrew