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.
Contents
Outputs
This encoder features three different types of outputs.
Analog
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 3pin.
This is the recommend 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.
DIP Swith Configuration
The DIP switches configure the resolution of the pulse and serial output. Per the datasheet:
| Switch 1 | Switch 2 | Pulses Per Rotation |
|---|---|---|
| OFF | OFF | 16 |
| ON | OFF | 64 |
| 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 |