Warning/indicator LED's and buzzer

[Paulham]

Hi guys,
Isit possible to wire some LEDs into the aio pro board so that armed status and gps fix is easily seen , also a buzzer would be good?

Simular to this http://diydrones.com/profiles/blogs/led-low-battery-warning-on

Thanks
Paul

[bunnygirl80]

Hi Paul,

You can connect your own buzzer, but you have to be careful that you don';t overload and damage the FC board. This is why it says on the board plans not to connect a buzzer directly. The boards are normally 5v, the buzzer can vary but as an example might be 3v. So, there is a 2v surplus. You have to use Ohm';s Law to work out what resistor you need to use the buzzer. Ohm';s Law states Resistance = Source Voltage - Sensor Voltage / Current of Sensor. So, FC board is 5v - Buzzer 3v = 2v / Buzzer 10mah = 200ohm Resistor. You can put the resistor either side of the buzzer cables. Once you';ve done this, just enable the BUZZER code in your FC software. I';m in the middle of enhancing the standard MultiWii software to add tones and volume to indicate things.

Good luck.