# BLDC Square wave inject(HFI) ## Overview The **bldc_hfi** project contains the sensorless speed control of DC brushless motors. - Use the **FOC** control algorithm - Sensorless control algorithm for **HFI** - Senseless low-speed performance ```{note} This demo is for experimental purpose only. It might have issues due to difference between hardwares. ``` ## Configurations - This program uses the **57B3C0730** brushless motor of " ShiDaiChaoQun". - Board settings refer to the development board documentation [Motor Pin](lab_board_motor_ctrl_pin) related content - Ensure that the development board power supply is sufficient, if the power supply is insufficient, remove the USB-HUB and insert multiple USB cables for power supply. ## Running the demo The motor will run at a low speed of 1 r/s. The serial console message is as follows: ```console Motor Inject demo. ``` ```{warning} - After the motor is powered on, it will first perform the "magnetic pole identification" action. If the motor is disturbed at this time, it will produce a jitter. - Pay attention to the current size, when abnormalities occur, please cut off the power at any time ```