Battery on the Expansion Board

[edelrabe]

Hi, I want to put the battery on the expansion board on the bottom of CF2.0
I don't like battery's wires and connector so the battery will supply the board through the expansion board legs.
Is this possible?

I suppose ground goes to GND (left 10 pin), but what about "+"? I can think of VCC 3V (left 1 pin), VCOM (right 9 pin) and VUSB (right 10 pin). Could you please suggest

[chad]

I'm certainly not the authority on such matters (have significantly more software experience than hardware), so don't take this as the final answer, but I'm not sure that VCC or VCOM will work to power the Crazyflie. VUSB might work but I'm not quite sure about that... Take a look at the "Pinout of the Expansion Board" section of this blog post for explanations of the pins you're thinking of using...

Specifically:

VCC – 3V0 regulated supply (max ~50 mA consumption). Only powered when the STM32F4 is powered.

VCOM – unregulated direct access to power after charger (max 1 A consumption). The voltage is VUSB if a charger is connected and VBAT otherwise. Currently this power supply is always on (even when the system is powered off) witch allow for making always-on expansion board. However we are looking at inserting a high-side switch which would allow also switching this supply off if needed, making prototyping and design of expansion boards a bit simpler.

VUSB – unregulated direct access to uUSB power. This can either be used to get uUSB power or to supply uUSB power to the platform (like an external charging board that powers and charges the system).

If you're mainly concerned about the wires and connector being unsightly or in the way, you might benefit from what I do, which is to simply twist the battery-side wire and flip the battery in the holder so that the wires can wrap around the side (see attached picture).

[tobias]

We where actually investigating this when we designed the expansion port. The problem is that the current consumption can be pretty high, up to 4-5 amps during bursts, 1.5-2 amps during hover. This requires low resistance power path. The expansion port connector can according to spec handle 1A, one would then need at least 2 x BAT and 2 x GND, preferably more.

Because of the above we abandoned the idea so you will have to stick with the battery connector...