current used by pyboard
Posted: Wed Feb 05, 2020 4:03 am
The specs for the v1.1 board list 56 mA as the current consumption at 168 MHz as 56 mA running and 16 mA "idling". I have a simple test program that uses a timer interrupt every 250 ms to toggle one of the boards leds and waits for a pin to go low. My code is simply:
set up timer interrupt to flash led
set up pin interrupt
while (True):
check flag set by a pin interrupt
if set
do something
else
wfi()
The led flashes just fine, toggling every 250 ms. I know that the system wakes up every ms, but even so I would expect it to be mostly asleep most of the time. However, when I measure the current consumption is is a pretty steady around 75 mA. I can account for the extra because of some leds on the motherboard that are on, and a bunch of IC's not doing anything but still drawing a few mA. This is without doing anything with the external pin, so there is no power consumption there.
I would have expected the number to be down closer to the 16 mA level on average, as measured with a multimeter on the input power wire. Is "idling" what you get with wfi()? Is there something about wfi() I don't know?
Thanks.
set up timer interrupt to flash led
set up pin interrupt
while (True):
check flag set by a pin interrupt
if set
do something
else
wfi()
The led flashes just fine, toggling every 250 ms. I know that the system wakes up every ms, but even so I would expect it to be mostly asleep most of the time. However, when I measure the current consumption is is a pretty steady around 75 mA. I can account for the extra because of some leds on the motherboard that are on, and a bunch of IC's not doing anything but still drawing a few mA. This is without doing anything with the external pin, so there is no power consumption there.
I would have expected the number to be down closer to the 16 mA level on average, as measured with a multimeter on the input power wire. Is "idling" what you get with wfi()? Is there something about wfi() I don't know?
Thanks.