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Discussions on how to get your MSP JTAG programmer up and running.
By willworknow
#54390
Hi,

I am using the MSP430-JTAG-ISO to connect to an electric meter running at 120 VAC. My target board is now floating at 120 VAC. I have tried two MSP430-JTAG-ISO units. The first unit would not work at all. The second unit seemed to work for a day but now I can no longer connect. I receive either "Cannot set VCC" or "VCC too high: 3.6V".

I have tried multiple setups:

VAC to Isolation XFMR to electric meter
VAC to Isolation XFRM to Computer to MSP430-JTAG-ISO

The electric meter has a 15 VDC unregulated supply that I am regulating to 3.3 VDC that supplies my target board. I have also tried disconnecting the 15 VDC and supplying the 3.6 VDC via a battery. No luck.

Has anyone had any luck with the MSP430-JTAG-ISO in a situation? Any ideas on what could be going on?


Thanks

Duane.
User avatar
By leon_heller
#54398
You might need a special "earth-free" test environment with an isolation transformer. It would be a lot safer, as well.

Leon
By willworknow
#54401
I am using two isolation transformers. One for the electric meter and one for my computer.