I'm trying to measure the power consumption of 128A1 mcu on Xplained A1 board.
The problem is that when i remove the J300 jumper (disconnects the VCC of the MCU and allows to put an ampermeter there) the MCU continues to work ! it gets 2.6v from somewhere..... ? (therefore any measurement will be wrong)
I use the xplain_power_consumption.c from AVR1010 application note. (it was made for the xplain rather than the xplained board)
it sets all pins as pullup except:
// Enable pull-down on PORTQ3. Disable audio Amp PORTQ.PIN3CTRL = PORT_OPC_PULLDOWN_gc; // Set PORTB1 as input w/ buffer disabled. (lightsensor) PORTB.PIN1CTRL = PORT_ISC_INPUT_DISABLE_gc;
Can anyone help me please to find the problem ?