A program for a fan with multiple speed settings using a STM32F303RE.
The fan built in this project has four separate speed modes, namely:
- Zero speed (fan is stopped)
- Half speed
- Full speed
- Variable speed
These modes can be switched to by the user through a set of buttons, with each button corresponding to a mode stated above.
In addition, in variable speed mode, the speed of the fan can be varied by the user using a potentiometer.
The buttons used for switching between modes are active-high buttons with 10 kilo-ohm pull-down resistors. These buttons are connected to pins PC1-PC4 on the Nucleo board.
Each of the pins PC1-PC4 is then connected to an interrupt line, which is asserted when the corresponding button is pressed.
The schematic for the speed control circuit is shown below.
The schematic for the motor driver circuit is shown below.
