Custom board power measurment and programming configuration

[robsrick]

Hello

I'm using the NRF52840DK with a custom shield on top that interfaces to my custom board. I use it to program and debug the DUT via the DK, talk to the DUT over serial port and perform power measurements using the PPK2.

the set up is as follows 

Im noticing that when the debugger is connected (which is all the time in normal use) im drawing milliamps of extra power i think due to the debugger connection?

is there some way of disabling the debugger progrmmatically or do i need to isolate the debug pins when not in use?

Regards

Robert

[Håkon Alseth]

Hi,

 

Im noticing that when the debugger is connected (which is all the time in normal use) im drawing milliamps of extra power i think due to the debugger connection?

Connected as in wired in, or connected as in used on the PC-side?

When a debug session is active, you will draw more current, as the debugger will force certain clock domains on, and you will see approx. 1.2 mA as your base sleep current.

 

Kind regards,

Håkon 

[robsrick]

Hi Hakon

connected as in wired in not actively debugging.

regards

Robert

[Håkon Alseth]

Hi,

 

How much added current are you seeing?

Could it be that you have a process that is continuously trying to connect to the debugger? An "nRF Terminal" instance in vscode?

 

Kind regards,

Håkon

[robsrick]

I'm seeing about 5mA. So i gather from what you're saying the configuration in my diagram should be low power when debugging not active?

if that's the case i'll look elsewhere, maybe im getting some current leakage else where on the board.

[Håkon Alseth]

Hi,

 

It should not draw that much current. Try disconnecting pin-for-pin between the DK and custom-board to see if you can find the signal(s) that draw excessive current.

 

Kind regards,

Håkon