LAUNCHXL-CC1352P: DIO16 & DIO17 pins cannot be used as UART

Hi Tim,

DIO16 and DIO17 are reserved on the LAUNCHXL-CC1352P for JTAG TDO/TDI operation through the XDS110 Debugger.  Have you removed the corresponding jumper pins and modified your target configuration file (ccxml) for 2-pin debug?  http://dev.ti.com/tirex/explore/node?node=ALFqIj4dX6S.TZRERoSphA__FUz-xrs__LATEST 

Can you also share how/where UART2 is initialized and used inside zed_sw?

Regards,
Ryan

Hi Ryan,

The TDO and TDI jumpers are removed (in fact, the board came without these jumpers installed). The ccxml file is configured for "cJTAG (1149.7) 2-pin advanced modes".

I have a TI-RTOS task that initializes UART2 (using UART_init() and UART_open()), then enters a loop that sends a request  (using UART_write()) and reads the response (using UART_read()) then sleeps for 10 seconds (using Task_sleep), wakes up and does it again. The device I'm communicating with over the UART is a PLC.

I did some more googling. Someone mentioned that you have to remove resistors on TDI and TDO lines. Do you think that's it?

BTW, my Launchpad says HW Rev B, SW SDK 2.40 on a label on the back of the board.

Tim

Ryan, here is more info.

Previously I was using SDK 3.20.0.68. At that time I configured the second UART with RX=DIO18 and TX=DIO19. This was before SysConfig, so I configured the second UART by adding RX and TX entries in BoardGpioInitTable[] .  This worked without problems.

A couple of days ago I upgraded to SDK 4.10.0.78. This SDK has SysConfig so I don't need to directly edit tables anymore. I used SysConfig to configure the second UART with RX=DIO17 and TX=DIO16, as I described in my original post. But it doesn't work.

Since I had the second UART working with before the upgrade, I decided to go back to using the pins I used then. So using SysConfig I configured the second UART to use RX=DIO18 and TX=DIO19. But using these pins don't work either.

Are you aware of problems with SysConfig? Before the upgrade, when I edited BoardGpioInitTable[] directly, these pins worked just fine with the second UART.

In SysConfig I see this:

UART was already enabled and it's configured like this (these are the default settings, I didn't change anything):

UART2 was there but was disabled, so I added it using the + sign, and configured like this:

So did I configure incorrectly?

"Use Hardware" is None. The only other choice is XDS100 UART. I don't think I want that since I'm not using this port with the debugger.

"UART Peripheral" defaulted to Any(UART0). The only other choice is Any(UART1), but that's already used by the first UART so I don't think I want that.

I selected TX = DIO19 and RX = DIO18,

Questions:

What's the difference between Any(UART0) and Any(UART1)?

The SDK has 2 drivers, UART and UART2 (the old SDK had UART only). What's the difference?

Why are there 2 drivers?

The second UART is named UART2. Does it work with the UART driver? Do I have to use the UART2 driver? 

Why are there 2 drivers?

As I said, the second UART worked just fine with the old SDK using the UART driver.

Please help. I have to get this working.

Hey Tim,

The resistors in question only connect to the Boosterpack Headers and should not affect UART communication.  Have you tried using UART2 with different DIO pins, or experimented with UART1 using DIO16/17?  Are you able to get UART2 to work outside of a Z-Stack project?  Debugged to confirm the pin states and proper function execution?  This testing could help us locate the source of the issue.  The LaunchPad revision you are using is the latest offered.

Edit: Thank you for providing the second thread, I will loop in a SysConfig expert to help comment based on your latest information.

Regards,
Ryan