Only compiled on Bebop, the constructor will need to be modified to
pass the pwm chip number and to create a PWM_Sysfs instead of a PWM_Sysfs_Bebop
in case it is used on a mainline linux board
It uses a heating resistor controlled by a pwm.
By changing the duty cycle of the pwm, we can control the temperature.
A simple PI algorithm is used in order to get to the correct temperature
fast enough and without too much overshoot
It is implemented as a member of the Util class in order not to make to much
modification to the current codebase
Julien BERAUD
Caio Marcelo de Oliveira Filho
Lucas De Marchi