Hey
i would like to set up some LEDs via shift registers and can’t find information how much current i can draw from the 3,3V pin to power them together.
So far i just found the limit per I/O pin (20mA).
Thanks for your help!
The information is found here for the regulator: http://docs.spark.io/hardware/#subsystems-power-regulator
Yes, but the USB2 input current ist 500mA, so how much can i use on the 3,3V pin?
it cant"t be 500 also, the core needs energy too.
In the entire documentation is no information how much i can draw
The 3.3V is from the LDO powered via USB.
1.) The core draws typically 300mA (http://docs.spark.io/hardware/#electrical-characteristics-power)
2.) The link i referenced you to states that the LDO can output a maximum of 500mA.
WIth that in mind you should probably be able to figure out?
More importantly, how much current would you like to draw? Perhaps there are some better alternatives as opposed to getting it directly from the Core.
1 Like
Ok, so there are 200mA to play with. sorry, i didnt get the connection.
@Moors7: i will need 46 leds for a clock which will need ~700mA. I plan using an 7805 to get a strong 5V circuit running the LEDs and the Core controlling the shift registers (74HC595)