Abstract

A method of generating multiple pulse width modulated signal with phase difference is presented in this work. The microcontroller used is PIC18F4520 and its output is used to drive Futaba RC servo motors directly. The concurrency of pulse width modulated signal in this work is relative, due to the fact that there is a finite time microcontroller period) between each instruction toggling the output pins. This finite time is equal to the minimum period of the microcontroller, which is 125 ns in this work. Also, the phase difference for the servo motors is set to 60° and is achieved by changing the duty cycle of each of the channels while the period remains at 20 ms for all the channels. The robotic fish using this software PWM code was able to attain a linear speed of 0.985 m/s.

Keywords:

Biomimetic, concurrent PWM, fish robot, PIC microcontroller, software PWM,

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.