I was able to track the issue down to my sensor circuit. The sensor was being powered from
"high current" P1_1 pin. I was able to verify that when the Wixel powered down, the voltage
between P1_1 and GND was 0V as expected. What I didn't expect, and what I noticed was that
there was a voltage between P1_1 and P1_7 ( Uart Rx pin ) being used to read serial data from
the sensor. I measured 0.5V between these pins while the Wixel was sleeping.
My sensor transmits TTL serial data, but the data needed to be inverted in order for the Wixel
to make sense of it. I had put together a small inverter circuit to invert the serial data from the
sensor to the wixel's uart rx pin. Things were working fine with serial data transmission but as
I found out the resistance between P1_1 and P1_7 was now only about 3K.
So, even though the wixel set all its pin to outputs prior to sleep, I was seeing 0.5V across these
pins. 0.5/3k = 166uA ! I figured this must be the extra current I was measuring. So, I swapped out
the 3.3k for 100k in the inverter. Now with the sensor connected, the sleeping Wixel draws only
130 uA with a battery voltage of 5.7 V. This is very close to your measurement and closer to my