Multi purpose automatic encoder

Tangshan encoder, a multi-purpose automatic encoder, is a sensor that converts mechanical geometric displacement on the output shaft into pulses or digital quantities through photoelectric conversion.

Principle of Multi purpose Automated Encoder

A photoelectric encoder is a sensor that converts mechanical geometric displacement on the output shaft into pulses or digital quantities through photoelectric conversion. The photoelectric encoder consists of an optical encoder disc and a photoelectric detection device. The optical encoder is a circular disk with a certain diameter and uniformly opened with several rectangular holes. Due to the coaxial relationship between the photoelectric encoder and the motor, the detection device detects and outputs several pulse signals when the motor rotates. To determine the direction of rotation, two sets of square wave signals with a certain phase difference are generally output.

A Hall encoder is a sensor that converts mechanical geometric displacement on the output shaft into pulses or digital quantities through magneto electric conversion. The Hall encoder consists of a Hall encoder and Hall elements. Hall code disks are arranged equidistant with different magnetic poles on disks of a certain diameter. The Hall encoder is coaxial with the motor. When the motor rotates, the Hall element detects and outputs several pulse signals. To determine the direction of rotation, two sets of square wave signals with a certain phase difference are generally output.

Precautions for Multi purpose Automatic Encoder:

1. The encoder has a speed limit. If it exceeds this limit, it will not function properly. This is a hardware limitation. In principle, the more lines there are, the slower the speed. When choosing a type, one should pay attention to this. The output of the encoder is usually open drain, so the IO of the microcontroller must be in a pull-up input state.

2. After the timer is initialized, the value of the CNT register is always the position information of the encoder. Increase during forward rotation and decrease during reverse rotation. This part does not require software intervention. The value of TIM-Period given during initialization should be the scale value of the entire circle of the encoder. After subtraction overflow, it will be automatically corrected to this number. If the added value exceeds this value, it will return to 0.

3. If we want to expand to multi cycle counting, we need an overflow interrupt.

4. The input pins of each timer in the encoder can be set and filtered by software

5. If there is no absolute position signal in the application or the count before receiving the absolute position signal after initialization is completed, it can only be a relative count. After receiving the absolute position signal, modify the value of CNT again. Encoders usually have zero bit signals, which can be combined with timers to capture inputs. After powering on, you need to move back and forth to find this position.

6. Even with filter count values, errors may occasionally occur. It is normal to have a majority or a minority in a circle, especially when the speed is relatively high, and it is necessary to have absolute position signals for correction. The absolute position signal does not need to be at the zero point. After receiving the signal, the CNT can be corrected to a fixed value.