CC2640R2F: UART to USB using microcontroller

How do you recommend interfacing with the microcontroller if this approach is not recommended?

Actually my concern us more to do with how I will add firmware to my microcontroller once I am using a standalone microcontroller. I am using launchpad to test my design. Are the UART pins a valid option for programming the device? If so, what hardware is required?

Hi Vineet,

You can program the device through the ROM bootloader (more details in the Technical Reference Manual and this app-note: www.ti.com/lit/pdf/swra466 ). This can also be evaluated in Flash Programmer 2,  by selecting the XDS110 Class Application / User UART option. 

The other alternative is to include a JTAG header on the board. 

Regards,
Fredrik

Thank you for your reply Fredrik. Unfortunately, I am not able to access the page you have sent me.I get an error message from the page. Also, are the stand alone microcontrollers packaged with the ROM bootloader?

Hi Vineet,

E2E thought the closing parenthesis was part of the link, I have corrected it. 

The ROM bootloader is available in all the CC13xx and CC26xx devices. 

Regards,
Fredrik

Hey Fredrik!

Thanks for correcting that! My last question is whether the device will enter ROM bootloader each time the device powers on if the bootloader is enabled? And if it is disabled, will I be able to reenable it without a UART connection. 

Okay, I think I am in bootloader mode. But unfortunately, I am not able to use a USB to UART bridge to connect to my device. (PC not recognizing the UART device). Do you have any recommendations on the bridge I should use?

e2e.ti.com/.../3119234

Frederik,

I am not looking to use the usb to uart connection from the debugger. I am attempting to create an interface independent of the debugger so that the final board can have only a UART header for programming purposes without a debugger.

Are there instructions on how to create this interface directly to UART to program the board. I don't see much documentation online.

Well, you need some kind of USB - UART interface, right? This could for example be an FTDI IC, or you could use the XDS110 found on the LaunchPad. You simply use wires to connect the UART signals from the debugger to the UART header on your board. 

If you actually have an RS-232 port on the computer you will be using for programming, you need to use an RS-232 driver connected to the UART header.

Interesting! Would the RX and TX pins available on the debug header on the Launchpad be the pins to use. Also, what other pins would be required, (3V3, GND, etc...?)?

The UART signals on the pin header close to the debugger on the LP would be the right pins. You also need GND, and the debug target must be at the same voltage potential as the LaunchPad.