can someone tell me what is the maximum current that the Vcc pin on maple can supply.
Also can someone give me the link or explain the usage of charg,bat,usb,ext pins on maple.
current rating of Vcc pin
(5 posts) (4 voices)-
poslathian
LeafLabsI dont know the exact rating off the top of my head. I will look it up. I believe its something like 500mA (maybe 700mA).
usb/bat/ext are the power selection pins. Your Maple should have come with a jumper placed on one of these pairs. This way if you plug in the battery and USB, or USB and external power, power does not flow backwards from one source into another. Simply choose which power source you would like to use and place the jumper there. Keep in mind that the battery will still charge even without jumping BAT, and the USB communication will still work even if USB is unselected. The jumper only selects which of those inputs go to the regulators to become VCC and VDDA (analog power).
CHRG is a completely different parameter, and should have a second jumper. When the jumper is connected, then the battery charging circuit is activated and you can charge standard single cell 3.7-4.2V lipo batteries. If you remove the jumper (or just put it on one pin instead of both) then bettery charging will not work.
The reason for this jumper is that the battery charging circuit behaves unpredictably when no battery is attached. Namely the "charging" and "done" indicator lights tend to randomly flick on and off. We thought this random flickering would be confusing to users, and therefore its possible to disable that whole circuit with the jumper.
DO NOT try and jump in the vertical direction! (connect CHRG to USB or USB to BAT...etc) This will brick your board. I recently did this by accident. Bricked...oops.
Posted 5 years ago # -
Antimatter, poslathian,
The VCC pin on Maple can supply a total of 250mA including the power that the STM32 draws but not including the power that is drawn by the battery charger (it draws from VIN).
Posted 5 years ago #
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