Part Number:MSP430F5529
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.