Hi there
Rishon here
I've been selected for the INSPIRE Science award competition in my country India. Therefore I planned and I've been researching for days. Finally I ordered the parts, and finished the build.
Its a robot, that helps the blind people to move safely, avoiding obstacles. But I've faced a couple of problems in making it work.
I've paired an Arduino Uno R3 to a L293D Motor Shield. I've also connected an Ultrasonic Sensor, and a servo motor, for full range of movement. The Motor Shield is connected to 4-geared DC Motors. I've written a code with help of resources from the internet. I compiled and verified the code, to see that all was okay.
When I connected the Arduino to my computer, everything was fine and the code uploaded successfully. But things were now getting strange. Every time I kept an obstacle in front of the sensor, (the servo motor should turn extremely right and left, finding a path) the servo motor, only turned right and then the Arduino unexpectedly disconnected and reconnected again from the computer. This happened several times. I thought that this was because of a faulty USB cable.
But when I connected the Arduino Uno to a external USB travel adapter, the robot worked normally.
So, I came to a conclusion that, If I supply the robot with an external power supply, then it would work. Therefore, I connected the robot with 3 18650 Batteries each supplying 3.7v in series.
But then I faced a another problem. I started the robot, this time with an external power supply (batteries - 11.1v). The robot started to work, but suddenly stopped after a minute. I could see that the lights were on but nothing was working. So I switched off the robot and I found that the Arduino Uno was getting as hot as coal. Then I understood that excessive power supply was the problem. But if I supply the robot with under this voltage rating the motors wont' spin. I am stuck in an Stucky situation. Please help.
