[X-NUCLEO-53L4A3 TOF Evaluation Board] Gesture Control Servo

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[X-NUCLEO-53L4A3 TOF Evaluation Board] Gesture Control Servo [Copy link]

[X-NUCLEO-53L4A3 TOF Evaluation Board] Gesture Recognition https://en.eeworld.com/bbs/thread-1299302-1-1.html
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In the previous three articles, I implemented gesture recognition. This article will share gesture control of servos.

【Servo control implementation】

The direction of the servo is controlled by a 20ms period PWM waveform. Here I first use TIM2 to output a 50Hz PWM waveform through PA1.

First, configure TIM2 CH2 to output a 50Hz PWM waveform. The configuration is shown in the figure below:

By checking the bus clock of the bus TIM, we configure it to 84MHz clock, then configure it to 84000 000/8400-1, which is 10Khz, and divide it by Period 200 to get a period of 50Hz. After generating the code, we also need to manually add code to set the startup of TIM2, that is:

	HAL_TIM_PWM_Start(&htim2, TIM_CHANNEL_2);  //开启定时器2的通道2
	__HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_2, 200/20);  //设置他的占空比为 1ms.

In the gesture recognition function, we set different direction gestures, modify the duty cycle, and finally realize real-time control of the servo:

		ret = isApproximatelyLinear(timeData, distanceData, DATA_POINTS);
		if (ret <100) 
			{
				printf("物体静止或近似静止。\n");
			}
			else if( ret >=100 && ret <5000)
			{
					double sum_t = 0, sum_d = 0, sum_tt = 0, sum_td = 0;
					for (int i = 0; i < DATA_POINTS; i++) {
							sum_t += timeData[i];
							sum_d += distanceData[i];
							sum_tt += timeData[i] * timeData[i];
							sum_td += timeData[i] * distanceData[i];
					}
					double denominator = DATA_POINTS * sum_tt - sum_t * sum_t;
					double a = (DATA_POINTS * sum_td - sum_t * sum_d) / denominator;
					if (a > 0) {
							printf("物体向前运动。\n");
							pwmvalue --;
						if(pwmvalue <5)
							pwmvalue = 5;
						__HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_2, pwmvalue);  //修改舵机运行位置
					} else if (a < 0) {
							printf("物体向后运动。\n");
						pwmvalue ++;
						if(pwmvalue >25)
							pwmvalue = 25;
						__HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_2, pwmvalue); //修改舵机运行位置
					} else {
							printf("物体静止或近似静止。\n");
						
					}
				} else {
						printf("数据点不近似在一条直线上，无法简单判断运动方向。\n");
				}

Through the schematic diagram, we find the position of A1 and connect A1 to the signal input position of the servo:

【Effect】

After downloading the program, you can control the servo by gestures. See the video for details:

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