Updated Board STM32F745 Discovery (markdown)

Board-STM32F745-Discovery.md

@@ -23,6 +23,10 @@ Cortex M7 STM32F746G
 * Flash file system not working yet
 * Use BOARD=STM32F7DISC to build micropython
 
+###Powering the Board###
+It is recommended that you power the board using the 5V connector or via a powered USB hub which is capable of delivering an amp or two. In my current setup the board is drawing about 850 mA with the backlight off.
+I've been using this hub: http://www.adafruit.com/products/961 I've also run the board without a hub (and the PC was limiting the current to 500 mA), which means that something was suffering for not having as much current.
+
 ###Entering DFU mode###
 The board doesn't provide a convenient way to enter DFU mode. There are several techniques that can be used to enter DFU mode.
 DFU mode is available on the USB FS connector (CN13)