2 layers55 × 85 mm
USB Knob
SteveLRojas/USB_Knob
A USB knob that can scroll, pan, adjust the volume, and more. Uses the CH552 USB microcontroller.
35 parts1CERN-OHL-P-2.0
2 layers55 × 85 mm
USB Knob
SteveLRojas/USB_Knob1A USB knob that can scroll, pan, adjust the volume, and more. Uses the CH552 USB microcontroller.
- Size
- 55 × 85 mm
- Copper layers
- 2
- Thickness
- 4.69 mm
- Parts
- 43
- Nets
- 38
- Pads
- 140
- Tracks, vias
- 246, 24
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 4 Oct 2024
- Updated
- 18 Dec 2025
Overview
USB Knob is an open-source printed circuit board by SteveLRojas, from the SteveLRojas/USB_Knob repository on GitHub, published under the CERN-OHL-P-2.0 licence. It is a 2-layer board of 55 × 85 mm with 43 parts on 38 nets, routed with 246 tracks and 24 vias.
It is built around the 74LVC1G17Z and CH552T. Its parts include 16 resistors, 9 capacitors, 4 switches, 3 ICs and 3 diodes. It belongs with the 8051 (CH55x, STC, AT89) boards of this library.
Main components
2
74LVC1G17Z
SOT-553-40℃~+125℃ 1 1 1.65V~5.5V 10uA 32mA 32mA 4.4ns@5V,15pF 74LVC Push-pull Schmitt trigger Unidirectional SOT-553 Buffers, Drivers, Receivers, Transceivers ROHSDiodes IncorporatedBuffers, Drivers, Receivers, Transceivers
CH552T
TSSOP-20-40℃~+85℃ 12Mbps 3.3V~5V USB 2.0 USB to UART、USB to SPI TSSOP-20 USB Converters ROHSWCH (Nanjing Qinheng Microelectronics)USB Converters
README
README.mdUSB_Knob
A USB knob that can scroll, pan, adjust the volume, and more. Uses the CH552 USB microcontroller.
What does it do?
This device is a computer peripheral, it can scroll, pan (scroll horizontally), and adjust the volume. It also has simple media controls such as play/pause, next, and prev.
How does it work?
The device has 3 buttons: left, center, and right. These 3 buttons are used to set the "mode" of the device, and when they are held down they act as function modifiers. The device also has a knob which has a fourth button, and is the most frequently used control on the device. Three indicator LEDs indicate the current "mode" setting of the device.
Device features
Scroll mode
- Press the left button to enter scroll mode.
- The knob button functions as the middle mouse button.
- While the left button is released spinning the knob scrolls vertically (like a mouse wheel).
- While the left button is pressed spinning the knob adjusts the scrolling speed (the speed range is 1 to 10).
Pan mode
- Press the center button to enter pan mode.
- If the mouse wiggler feature is enabled (option set at compile time) the knob button toggles the mouse wiggler on/off. The mouse wiggler only acts when the knob is in pan mode, but the on/off state is maintained even when the device is in a different mode.
- If the mouse wiggler feature is not enabled then the knob button functions as the middle mouse button.
- While the center button is released spinning the knob scrolls horizontally.
- While the center button is pressed spinning the knob adjusts the scrolling (pan) speed (the range is 1 to 10).
Volume mode
- Press the right button to enter volume mode.
- While the right button is released the knob button acts as a mute button.
- While the right button is pressed the knob button acts as a play/pause button.
- While the right button is released spinning the knob adjusts the volume.
- While the right button is pressed spinning the knob functions as media next/prev buttons.
Parts
43| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | 1k | Resistor_SMD:R_0805_2012Metric | R6, R7, R8, R9, R10, R11 |
| 4 | 0.1u | Capacitor_SMD:C_0805_2012Metric | C2, C3, C8, C9 |
| 4 | MountingHole_Pad | MountingHole:MountingHole_3.2mm_M3_Pad | H1, H2, H3, H4 |
| 3 | 10k | Resistor_SMD:R_0805_2012Metric | R12, R13, R14 |
| 3 | 1K | Resistor_SMD:R_0805_2012Metric | R3, R4, R5 |
| 3 | LL3301NF065QG | SamacSys_Parts:LL3301NF065QG | S1, S2, S3 |
| 3 | ORANGE | LED_SMD:LED_0805_2012Metric | D1, D2, D3 |
| 2 | 0 | Resistor_SMD:R_0805_2012Metric | R15, R16 |
| 2 | 0.01u | Capacitor_SMD:C_0805_2012Metric | C6, C7 |
| 2 | 20p | Capacitor_SMD:C_0805_2012Metric | C4, C5 |
| 2 | 5K1 | Resistor_SMD:R_0805_2012Metric | R1, R2 |
| 2 | 74LVC1G17 | Package_TO_SOT_SMD:SOT-353_SC-70-5 | U2, U3 |
| 1 | 10u | Capacitor_SMD:C_1206_3216Metric | C1 |
| 1 | CH552T | Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm | U1 |
| 1 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Horizontal | J3 |
| 1 | Conn_01x03 | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Horizontal | J2 |
| 1 | Crystal_GND24 | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | RotaryEncoder_Switch | Rotary_Encoder:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | SW1 |
| 1 | USB_C_Receptacle_USB2.0 | Connector_USB:USB_C_Receptacle_HRO_TYPE-C-31-M-12 | J1 |
More from SteveLRojas/USB_Knob
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USB Knob
SteveLRojas/USB_Knob
A USB knob that can scroll, pan, adjust the volume, and more. Uses the CH552 USB microcontroller.
31 parts1CERN-OHL-P-2.0
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Questions
How big is the USB Knob PCB?
It measures 55 × 85 mm and has 2 copper layers, 4.69 mm thick.
What parts does the USB Knob use?
43 parts, built around the 74LVC1G17Z and CH552T. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the USB Knob KiCad files?
From the SteveLRojas/USB_Knob repository on GitHub, at the commit this page was made from: the board is HW/USB_Knob/V1.1/USB_Knob.kicad_pcb and its schematic HW/USB_Knob/V1.0/USB_Knob.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the USB Knob design in my own project?
Its repository publishes it under the CERN-OHL-P-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).