This example mainly illustrates how to drive a brushed DC motor by generating two specific PWM signals. However the PWM signals from ESP chip can't drive motors directly as the motor usually consumes high current. So an H-bridge like [DRV8848](https://www.ti.com/product/DRV8848) should be used to provide the needed voltage and current for brushed DC motor. To simplify the DC motor control of MCPWM peripheral driver, there's a component called [bdc_motor](https://components.espressif.com/component/espressif/bdc_motor) which abstracts the common operations into a generic interface. The most useful operations are: `forward`, `reverse`, `coast` and `brake`.
To measure the speed of motor, a photoelectric encoder is used to generate the "speed feedback" signals (e.g. a pair of quadrature signal). In the example, we use the PCNT peripheral to decode that quadrature signals. For more information, please refer to [rotary encoder example](../../pcnt/rotary_encoder/README.md) as well.
The example uses a simple PID algorithm to keep the motor spin in a stable speed. Like the [bdc_motor](https://components.espressif.com/component/espressif/bdc_motor), the [PID component](https://components.espressif.com/component/espressif/pid_ctrl) is also managed by the component manager. These components' dependencies are listed in the [manifest file](main/idf_component.yml).
To help tune the PID parameters (i.e. `Kp`, `Ki` and `Kd` in the example), this example supports to log a short string frame of runtime motor speed. The string frame can be parsed by [Serial Studio](https://github.com/Serial-Studio/Serial-Studio). This example also provides the [communication description file](serial-studio-dashboard.json) out of the box, which can be loaded by Serial Studio and then plot the curves as follows:
* The PID parameter set in this example might not work well in all kinds of motors, because it's not adaptive. You need to fine tune the parameters again by yourself.
