1. Assembly
Kittenbot:
End Product:
In the assembly process, I don’t think the sequence of assembly steps is very reasonable. The servo is the very first part to assemble. However protuberant servo and control chip of ultrasonic unit is a big problem when assembling the motors etc. on the other side. When I need to twist the screw very hard on the other side, I am so afraid I will broke the chip on the other side.
2. Coding
I decide to make an ultrasonic obstacle avoidance program. Ultrasonic unit and servo unit will be used. On start, I set the ultrasonic unit to the straight ahead. Then the kittenbot will move forward and show green light. If it meets obstacle, the light will turn red and it will pause and turn left for 90 degrees. During each pause, ultrasonic unit will swing left and right to simulate the process of detecting.
3. Effects Display
4. Reflection
Broadly, the program is successful. However, there is several minor problem. First, servo is not able to turn ultrasonic unit to straight ahead. The problem was solved when I set the servo to turn to 70 on start. I assumed it to be hardware problem. The other problem is that if the obstacle is lower than the height of ultrasonic unit, then kittenbot will not stop when it meets the obstacle. Following video shows the problem. However, it is still a hardware problem. Thus I will consider it to be minor problem.
I’m unsure about the initial servo orientation, but as the servos are analog, I suspect you are on the right track with the hardware comment.
I would be interested in seeing this idea of “the obstacle was too low” evolve into “the sensor was not aiming down enough”.
May be something else interesting to see would be that as it moves, it scans both left and right to decide whether there any upcoming obstacles.