My team is working on a line following hovercraft. We are left with the line following part. For that we decided to use an Arduino Uno board.
The problem is that nobody in our team has any experience in working with arduino. As a result 4 arduino boards got damaged.
We are using a brushless motor for providing lift, servo motor to control the rotation of rudder, 3 IR sensors to detect the path. The signals from the sensors are fed into A0,A1,A2 analog pins of arduino board. The pwm pin6 is connected to the servo motor. As we are using a brushless motor we need to use an ESC. A 30 amp ESC is being used which is powered by a 11.1V 1300mAh Lipo Battery. The signal pin of esc is connected to pin5(pwm) of arduino. The ESC and the 3 sensors are powered by the 5V Pin of the arduino board. Also IC 7806 is used to deliver 6V to servo.
Initially the arduino board was working fine(power to the board was supplied from laptop) as we were testing the rudder,sensors,motor separately and we were able to upload the code as and when required. At one point of time we thought of providing a common ground for all the components.
So we disconnected the USB cable from the arduino board, took a wire and connected the battery gnd to arduino gnd pin.
(remaining connections were intact). To our surprise the arduino board started functioning without any input power being fed.
(Vin pin of arduino is not connected to battery). And post this incident the board got damaged. We weren't able to upload the code as the laptop was unable to detect the serial port."SERIAL PORT COM6 NOT FOUND" was the message appearing every time we tried to upload.
Then using a multimeter I measured the drop betweenVin and gnd pin of arduino(connected to battery gnd)(connections intact as mentioned before). It showed 8V(without Vin pin connected to any source). And I found out that ESC was supplying power to the board.
I am unable to figure out how can ESC power the arduino and what was the reason behind board's damage.
Can anybody help me out?????
Waiting for replies............