This is a board that allows the Kookaberry to operate peripherals that require current greater than 100 milliamps. For example, the mini-pump used with the WaterMe App has to use this board.
Power to the Kookaberry
The Kookaberry has a generous and protected power supply which allows voltages to be used from different sources. Internally it takes an incoming voltage from up to three sources (simultaneously if required) and converts this into a board power supply voltage of
3.3 volts. This 3.3 voltage (Vcc) powers all the three microcontrollers on the Kookaberry as well as the peripheral components such as the display, serial random access memory (serial RAM), accelerometer, magnetometer, LED’s etc.
The current drain on the incoming power supply is quite small and typically sits at around 20mA peaking up to around 35 mA when the display is heavily used.
An allowance has been made for the Kookaberry to draw up to around 50 mA under certain operating conditions. An additional 100 mA has been allocated to power external peripherals associated with operating the Kookaberry including connected sensors. A user
of the Kookaberry must consider this when connecting sensors to the board.
THIS IS THE REASON THAT A MOSFET OR A RELAY MUST BE USED WHEN A PERIPHERAL IS LIKELY TO DRAW A CURRENT HIGHER THAN 100ma.