Servo PWM signal introduced

Shenzhen Shenchuang Hi-tech Electronics Co., Ltd(SChitec) is a high tech enterprise which specialized in phone accessories production and sales. Our main products include travel chargers, car chargers, USB cables, power banks and other digital products.All products are safe and reliable, with unique styles.products pass certificates like CE,FCC,ROHS,UL,PSE,C-Tick,etc,  If you are interested in, you can contact ceo@schitec.com directly.

Stay Charging Safely with SChitec

Servo PWM signal introduced

1. The PWM signal definition of the PWM signal is characterized by the time width between the rising and falling edges of the pulse width modulation signal. The servos we currently use depend mainly on the model industry standard protocol. A gradual independence of the robot industry, a new servo protocol has been introduced. These servo motors can only be used with industrial robots and are not applicable to traditional models. now. The advantages of the steering gear have been realized, its cost is low and its rotation angle is large (current production can reach 185 degrees); the disadvantage is the PWM format after all the control is more complicated Adopted. However, digital servo is with low requirement of PWM signal: (1), you don't need to receive instructions from time to time to reduce CPU fatigue; (2) can self-lock position, position tracking, stepper motor; normal Is over. Some points to note about the PWM format: (1) Rising edge is 0.5 ms and 2.5 ms; at least 0.5 ms (2) HG14 M Digital servo falling edge timing is not required. Currently 0.5 ms is used. In other words, the PWM waveform can be a standard square wave with a duration of 1 ms; (3) For HG0680, analog servos that require continuous plastic gears can also input standard squares with a PWM signal supply period of 1 ms. The wave, the follow-up performance displayed at this point is very good and very close.

2. PWM signal control accuracy

When using an 8-bit microcomputer AT89C52CPU, the data resolution is 256. After the steering gear limit parameter experiment, it should be divided into 250 copies. 0.5 ms --- width 2.5 ms, 2 ms, 2000 us =. 2000uS ÷ 250 = 8 us, next: PWM control accuracy is 8 us. We can control steering gear rotation and positioning in 8 units. Servo must be rotated 185 degrees, 185 degrees ÷ 250 = 0.74 degrees: Servo controller accuracy is 0.74 degrees.

1 DIV = 8 us. 250DIV = 2 milliseconds time base register value is: (# 01 H) 01 --- (# 0FAH) 250. The total of 185 degrees is divided into 250 locations, each location called 1DIV. After: 185 ÷ 250 = 0.74 degrees / DIV PWM rising edge function: 0.5 ms + N × DIV 0us≤N × DIV≤2 ms 0.5 ms≤0.5 MS + N × DIV≤2.5 ms