If you are using a G2 LunchPad, there is provision to use the external 32768 Hz crystal and the crystal is provided by TI. It may still be difficult to solder that on. And it may be even more difficult to get it to work reliably. There is an alternative. You could use the "Application UART" (aka "back channel UART") as reference. At 9600, if you use the PC to send the character "U" repeatedly, the duration the "low" periods are 104.17 usec. This is slow enough and accurate enough to be used to calibrate your DCO. Using Timer Capturing to determine the DCO calibration is not difficult to do. Any Good Samaritan volunteer?
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