How do I power on the wipy2.0 without expansion

[minkley]

Just bought a wipy 2.0 without expansion (out of stock) . how do I power on the wipy2.0? I see it two power pins 3.3v and 5v are both required to power on the device one or the other.
tks

[robert-hh]

Just power through 5V and GND. The 3.3v Pin is an output form the internal regulator and may be used to supply other devices, as long as their power consumption is small (< 100 mA)

[livius]

@robert-hh

as long as their power consumption is small (< 100 mA)

you mean <1200 mA? not 100

[robert-hh]

For the power drawn from the 3.3V Output of the wipy I definitely not mean 1200 mA. That would be a power dissipation of the internal regulator of 2W, which is way to much. B.T.W: The spec says 500 mA, which is still a lot.

[livius]

@robert-hh
but pinout say max 1.2A
https://www.pycom.io/wp-content/uploads/2016/11/wipy_pinout.pdf

[bmarkus]

In October I got this answer:

https://forum.pycom.io/topic/62/3-3v-output-max-load-current

[robert-hh]

I looked into the specs on the Pycom product pages, but could not find the schematics, so I assume a linear regulator like the one used in WiPy1.
Whatever it says, 2W power on a small SMD package just sitting on an PCB. I do not know which package is used, but under best assumptions and a 2 square inch PCB the thermal figure would be between 50 and 90 °/W, meaning that at 1.2A the package will be between 100° and 180° warmer than the environment, which sound like a substantial thermal stress. And not taking into account the current consumed by WiPy itself.
The regulator may be able to supply a peak current of 1.2 A

[robert-hh]

Update: The product sheet tells, it uses a switching regulator. That changes the picture, since then the power dissipation is much lower, and the output current might be higher, even 1.2 A. Still it would be nice to have access to the schematics.

[minkley]

Thanks for the info that is a great help. I have a breadboard power source which is around 500w/5V which I can use