Some more info -
When using VSYS, the GPIO "low" is at 100mV.
When using the USB connector, its at 0.
What I can see on the GPIO are:
1. 50mV bumps @ ~10Hz
2. Erratic spikes at several 100mV
3. A 100mV offset but only when using VSYS
Attaching some images -
1 image shows all 3 - offset, spikes, bumps.
1 image shows 2 - offset and bumps.
1 image shows none (when using the USB connector)
In the spec I saw mention of the SMPS having two modes - PFM and PWM - the first mode of operation may be an explanation for the 10Hz bumps (the can be seen inverted on the 5V line as dips).
I thought perhaps to make the SMPS switch to PWM and see if this has an effect, but could not find how to do it.
Its supposed to be tied to GPIO23, but seems ambiguous as to controlling it on the pico W.
Is it SW controlled or HW ?
When using VSYS, the GPIO "low" is at 100mV.
When using the USB connector, its at 0.
What I can see on the GPIO are:
1. 50mV bumps @ ~10Hz
2. Erratic spikes at several 100mV
3. A 100mV offset but only when using VSYS
Attaching some images -
1 image shows all 3 - offset, spikes, bumps.
1 image shows 2 - offset and bumps.
1 image shows none (when using the USB connector)
In the spec I saw mention of the SMPS having two modes - PFM and PWM - the first mode of operation may be an explanation for the 10Hz bumps (the can be seen inverted on the 5V line as dips).
I thought perhaps to make the SMPS switch to PWM and see if this has an effect, but could not find how to do it.
Its supposed to be tied to GPIO23, but seems ambiguous as to controlling it on the pico W.
Is it SW controlled or HW ?
Statistics: Posted by djinng — Sat Mar 02, 2024 1:08 pm