In this Section
PyCubed uses the TI BQ25883 USB battery charging IC to manage USB-C power delivery. This provides an easy way of powering the board and/or charging the batteries.
(All of this is made possible by the Inhibits & RBF Header. Make sure to review that page to understand how different power arrangements are achieved)
When USB power is first applied, the BQ25883 will look for an attached battery and and trickle-charge it (if possible) to 8.4V at a rate of 200mA.
VCHRG
and GND
jumpers of the RBF header must be installed in order to charge the batteries. See RBF page above for more details.
VUSB
jumper is also installed or both high side and low side screw terminals (inhibits) are jumpered.If VUSB
jumper is installed (or the inhibits are connected, see above) PyCubed will be powered and the MCU will boot. Part of the booting process initializing hardware and software (i.e. when from pycubed import cubesat
is called), during which USB battery charging is intentionally turned off.
cubesat.charge_batteries=True
. This can be done from the REPL or within your main.py code.
cubesat.charge_batteries=False
/lib
folder) to see what functions are available. PyCubed supports the USB-C Power Delivery (PD) specification, meaning the BQ25883 could be configured for up to ~2A charge current if desired. Stick to the defaults to avoid undue stress on your battery cells.USB battery charging will automatically shut off after 12 hours of continuous charge operation. The green “CHRG” LED (D5) will blink once per second if the safety timer expires.
The USB battery charger