This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CCS/MSP430F5529: Cannot connect to target using external power supply

Part Number: MSP430F5529
Other Parts Discussed in Thread: MSP430G2221

Tool/software: Code Composer Studio

I am using the MSP430F5529 launchpad to program an MSP430G2221 on an external board.

It has been smooth until I tried to program the MSP430G2221 using its own power supply. It consists of a 25V switching supply which is connected to a parasitic supply. Then it goes to an LDO and finally to the MSP430G2221. Both grounds, the one on the launchpad and the one of the MSP430G2221, are connected. 

I have measure the voltage between grounds and it is 0V, as expected. The voltage between the 3V3 output of the launchpad and the LDO output is -190mV. I am not sure if this voltage difference is enough to make the communication fail.