29 917
modifications
Modifications
Sauter à la navigation
Sauter à la recherche
Ligne 35 :
Ligne 35 : − + Ligne 46 :
Ligne 46 : + + Ligne 52 :
Ligne 54 : − + + + + + + + + + +
→Pico and PowerBoost
[[Fichier:ENG-CANSAT-PICO-POWERING-10.png|800px]]
[[Fichier:ENG-CANSAT-PICO-POWERING-10.png|800px]]
Here how it works.
Here how it works. Please note that {{underline|only the Pico Micro USB}} is used in this setup.
{{underline|'''When Pico is plugged on computer:'''}}
{{underline|'''When Pico is plugged on computer:'''}}
# The Pico VSYS pin is also at 5V. Thanks to the diode, the 5V VSYS does not inject current into the 5V output of the PowerBoost charger.
# The Pico VSYS pin is also at 5V. Thanks to the diode, the 5V VSYS does not inject current into the 5V output of the PowerBoost charger.
# The 5V VBUS (on the Pico) do power the PowerBoost on the USB pin. As a result, the PowerBoost does charge up the Lipo.
# The 5V VBUS (on the Pico) do power the PowerBoost on the USB pin. As a result, the PowerBoost does charge up the Lipo.
Summary: the Pico is running and the Lipo is charging.
{{underline|'''When Pico is UNPLUG from computer:'''}}
{{underline|'''When Pico is UNPLUG from computer:'''}}
# The Pico VSYS is at 0V (but this will change).
# The Pico VSYS is at 0V (but this will change).
# The Pico regulator is not powered
# The Pico regulator is not powered
# The PowerBoost is running and generating 5V on its '''5V Output''' Pin. The 5V is
# As the PowerBoost is running, it generates 5V on its '''5V Output''' Pin. The 5V push the current through the diode to '''VSYS'''
# The Pico VSYS now receives 5V (a bit lower due to the diode lost). So the Pico regulator is powered and generating 3.3V.
Summary: the Pico is running and the Lipo is discharging.
{{underline|'''How to power off:'''}}
To power-off the Pico when the USB is unplug on the Pico, we have the following options:
# Tied the '''Pico 3V3_EN pin''' to the ground : that disable the Pico but the Powerboost is still discharging!
# Tried the '''PowerBoost EN pin''' to the ground : this disable the PowerBoost which stops to power up the Pico.
== Additional ressources ==
== Additional ressources ==