Baolian SDVX Encoders

The Chinese company Baolian sells a knob assembly that is designed to be a drop-in replacement for the official arcade assembly. It uses a hall effect sensor and a magnet mounted to the shaft to determine the angle.



This encoder features three different types of outputs.


This output mimics the hall effect sensor used in the arcade cabinet, ranging from 0V to 3.3V through a full rotation. Included with the encoder is an adapter board that scales the output from 0V to 5V.

The connector is JST PH 3 pin.

The Sensatec potentiometer on the arcade cabinets use JST ZH, so an adapter cable is required.

This is the recommended output method.

Pulse Output

This output sends one pulse at the set resolution, but it is not a quadrature output. One wire outputs pulses on a clockwise rotation, while the other wire outputs pulses on a counterclockwise rotation.

The connector is JST PH 6 pin.

This is an open-drain output, so pull-up resistors are required for the signal to return high.

If spun too fast, there is no longer a separation between pulses. Effectively, this mode is like holding a button for the encoder instead of giving proper analog control. It is not recommended.

Serial Output

The serial output has the following configuration:

  • Baud Rate: 115200
  • Date Bit: 8
  • Parity Bit: None
  • Stop Bit: 1

And will only send one of the two messages:

  • Spin Right: 0xFF 0x00 0x00 0x01
  • Spin Left: 0xFF 0x00 0x00 0xFE

The connector is JST PH 4 pin.

Due to the fairly high baud rate, hardware serial is likely required to capture signals correctly.


See the following image for pinouts:

DIP Switch Configuration

The DIP switches configure the resolution of the pulse and serial output. Per the datasheet:

Switch 1 Switch 2 Pulses Per Rotation
OFF ON 512
ON ON 1024

The last switch configures the duration of the pulse output.

Switch 3 Pulse Length
ON 0.5ms
OFF 8ms