

FM3 mainboard
The repository for FLipMouse (Finger and LipMouse)
- Size
- 32 × 61.5 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 54
- Nets
- 43
- Pads
- 161
- Tracks, vias
- 432, 62
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 30 Jun 2015
- Updated
- 8 Sep 2026
Overview
FM3 mainboard is an open-source printed circuit board by asterics, from the asterics/FLipMouse repository on GitHub. It is a 2-layer board of 32 × 61.5 mm with 54 parts on 43 nets, routed with 432 tracks and 62 vias.
It is built around the MIC5504-3.3YM5, TSOP4838 and SFH 4045N, with the FC68125, PESD5V0S1BA,115-MS and EVQP7C01P among its other parts. Its parts include 12 connectors, 8 diodes, 7 capacitors, 3 resistors and 2 ICs. It belongs with the keyboards and input and computers and single-board computers boards and the RP2040 boards of this library.
Main components
9MIC5504-3.3YM5
SOT-23-5-40℃~+125℃@(Tj) 1 120uVrms 15uA 180mV@(300mA) 3.3V 300mA 5.5V 75dB@(1kHz) Fixed Over Temperature Protection、Enable Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSTECH PUBLICVoltage Regulators - Linear, Low Drop Out (LDO) RegulatorsTSOP4838
SIP-3-2.54mm-25℃~+85℃ 2.5V~5.5V 38kHz 45m 45° 700uA SIP-3-2.54mm Infrared Remote Receiver (IRM) ROHSVishay IntertechnologyInfrared Remote Receiver (IRM)SFH 4045N
SMD,3x2.6mm-40℃~+85℃ 1.6V 140mW 42nm 5V 70mA 90mW/sr@IF=70mA 950nm 9° SMD,3x2.6mm Infrared LED Emitters ROHSOSRAM Opto SemiconInfrared LED EmittersFC68125
-Audio Connectors (Headphones)CliffPESD5V0S1BA,115-MS
SOD-323SOD-323 ESD and Surge Protection (TVS/ESD) ROHSMSKSEMIUncategorisedEVQP7C01P
SMD,3.6x3.5mm-20℃~+70℃ 1.35mm 100,000 cycles 12V 2.2N 3.55mm 3.5mm 50mA PC Pin Rectangular Button SPST Surface Mount, Right Angle SMD,3.6x3.5mm Tactile Switches ROHSPanasonicTactile SwitchesPKMCS0909E4000-R1
SMD,9x9mm-40℃~+85℃ 1.9mm 12.5V 4kHz 65dB 9mm 9mm Passive (Externally Driven) Piezoelectric SMD,9x9mm Buzzers ROHSMurataBuzzersSKHHLQA010
弯插-4P,6x6mm-40℃~+90℃ 1 million cycles 12V 1N 50mA 6mm 6mm 8.35mm PC Pin Right Angle Round Button SPST-NO 弯插-4P,6x6mm Tactile Switches ROHSALPSALPINETactile SwitchesSSM-104-L-SV
SMD,P=2.54mm-55℃~+125℃ 1 1x4P 2.54mm 4P 5.2A 572V 7.37mm Phosphor bronze Square Hole Surface Mount,Vertical Tin Top SMD,P=2.54mm Female Headers ROHSSamtecFemale Headers
README
README.mdFLipMouse
The FLipMouse (a.k.a. Finger- and Lipmouse) is a replacement for a normal PC mouse / keyboard / joystick. Instead of moving the mouse device with your hand and clicking with your fingers, the FlipMouse can be controlled by applying very low forces to the mouthpiece (joystick) with your lips, fingers or other body parts. The clicking functionality can be accomplished by sip- and puff-activities into the mouthpiece or via external switches. All settings and functions of the FlipMouse can be tailored to specific user capabilities or needs. Multiple settings can be stored into the device and changed via desired user actions. Additional features like built-in environmental control via infrared, optional bluetooth-add-on module for controlling smartphones/tablets or complete software-based control of all functions via serial command interface make the FlipMouse one of the most flexible alternative input devices available today.

The FlipMouse might be used as a full replacement of standard computer input devices and can also be used for accessing smartphones or tablets (via the standard HID support or accessibility features). It can be useful for people with motor disablities, computer gamers, musicians or people who want a hands-free computer access for other purposes.
Our goal is to provide an affordable DIY-solution for everybody who wants to use a PC or smartphone with non-standard interaction methods.
Please note: There are different versions of the FLipmouse hardware and software! This Github repository refers to the current Version 3. If you are looking for Version 2, use this repository: FLipmouse V2.
The DIY construction kit
The official FlipMouse DIY kit is available for purchase via https://asterics-foundation.org. We provide a Construction Manual which shows how to assemble the kit. In case you want to buy the components from other sources, a full part list is available in folder Hardware. The design files for the enclosure can be found in folder Hardware/case-design. The PCB designs (schematic and layout) have been made with KiCad and are available in folder Hardware/PCB-design
Hardware and Features
The FLipMouse uses an Arduino Nano RP2040 Connect microcontroller (ARM CortexM0+ architecture) as main module. Movements of the mouthpiece are measured via Strain Gauges (DMS), which detect small forces applied to the mouthpiece / joystick. The sip/puff actions are detected by a pressure sensor. Via two 3.5mm jack plugs, external momentary switches can be connected. From all these user inputs, desired actions can be assigned via the FlipMouse WebGUI, for example mouse/keyboard or joystick actions via USB HID. Via bluetooth, BT-enabled devices can be paired and mouse/keyboard functions can be used wirelessly. Furthermore, an IR-receiver module and a IR-LED allow recording and replay of arbitrary infrared remote control commands.
Software
The FLipMouse firmware is based on the Arduino framework. The firmware implements a composite USB HID device (mouse, keyboard, joystick and a serial port in one device). The mouse and keyboard device classes are used to transmit different keys or mouse actions to the host device. The serial port is used configure the FLipMouse (or even use it as a mouse simulator via AT commands). Multiple configuration settings can be saved (stored in an EEPROM module) and changed via desired user actions. Since Version v3.7, the firmware development for the FlipMouse (and our other alternative input devices) happens in a dedicated repository, see FabiWare. All firmware versions until v3.6.2 can be found in this repository by browsing the release section or by using the desired tags. For information about (modifying) the older FLipMouse V2 firmware (for the TeensyLC microcontroller), see https://github.com/asterics/FLipMouse/wiki/dev-firmware Please note the COM-Port installation instructions for older Windows systems (Win7/8) here.
Configuration Manager
All settings of the FLipMouse can be changed via the FlipMouse Configuration manager
Using the configuration manager in the Chrome/Edge web browser, you can assign different actions to all hardware inputs of the FLipMouse (mouthpiece, sip and puff, external buttons,...).
The Configuration manager can also be used to update the firmware of the FlipMouse and the optional Bluetooth module.
More Information can be found in the user manual: user manual (english version), user manual (german version).
Cleaning and Safety
IMPORTANT: If the mouthpiece is exposed to saliva, please clean/replace the mouthpiece (or its filter) on a regular basis, see Safety Instructions

Links and Credits
Most of this work has been accomplished at the UAS Technikum Wien in course of the R&D-projects ToRaDes (MA23 project 18-04), WBT (MA23 project 26-02) and InDiKo (MA23 project 38-09), which have been supported by the City of Vienna.
Have a look at the AsTeRICS Foundation homepage for applications and our other Open Source projects:
- FABI - the Flexible Assistive Button Interface - an open source switch interface for USB HID and Bluetooth.
- The FLipPad controller - a flexible touchpad for controlling computers and mobile devices with minimal muscle movement.
- Asterics Grid Open Source AAC - an open source, cross plattform communicator / talker for Augmented and Alternative Communication (AAC).
- The AsTeRICS framework - provides high flexibility for building Assistive Technology solutions.
Support us
Please support the development of Open Source Assistive Technology projects by donating to the AsTeRICS Foundation:
Parts
54| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | Fiducial | Fiducial:Fiducial_0.5mm_Mask1mm | FID1, FID2, FID3, FID4, FID5, FID6 |
| 6 | TestPoint | Connector_Wire:SolderWirePad_1x01_SMD_1x2mm | J6-1, J6-2, J6-3, J7-1, J7-2, J7-3 |
| 4 | 100n | Capacitor_SMD:C_0603_1608Metric | C2, C4, C5, C6 |
| 4 | SFH4045 | FLipMouse:SFH4045N | D1, D2, D3, D4 |
| 2 | 1uF / >6.3V / X7R | Capacitor_SMD:C_0603_1608Metric | C1, C7 |
| 2 | 5mm WS2812B | FLipMouse:NeopixelTHT | D5, D6 |
| 2 | DNP | Resistor_SMD:R_0603_1608Metric | R2, R3 |
| 2 | FC68125 | FLipMouse:FC68125 | J3, J4 |
| 2 | MountingHole | MountingHole:MountingHole_2.2mm_M2_ISO7380 | H1, H2 |
| 2 | PESD5V0S1BA,115 | Diode_SMD:D_SOD-323 | D8, D9 |
| 2 | SolderJumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm | JP3, JP4 |
| 2 | SolderJumper_2_Open | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP1, JP2 |
| 1 | 009159005551906 | FLipMouse:009159005551906 | J6 |
| 1 | 100uF/6.3V | Capacitor_SMD:C_1210_3225Metric | C3 |
| 1 | 4k7 | Resistor_SMD:R_0603_1608Metric | R1 |
| 1 | 690367280676 | FLipMouse:690367280676 | J5 |
| 1 | ABX00052 - Arduino Nano RP2040 Connect | FLipMouse:NANO_33_Footprint_SMD_Castell_AlignmentHoles | A1 |
| 1 | BSS806 | Package_TO_SOT_SMD:SOT-23 | Q2 |
| 1 | Conn_01x04_Male | FLipMouse:pressure_sensor | J1 |
| 1 | EVQP7C01P | Button_Switch_SMD:SW_SPST_EVQP7C | SW2 |
| 1 | Logo_CE | Symbol:CE-Logo_8.5x6mm_SilkScreen | LOGO3 |
| 1 | Logo_FM | FLipMouse:flipmouse_11x5 | LOGO1 |
| 1 | Logo_KiCAD | Symbol:KiCad-Logo_5mm_SilkScreen | LOGO2 |
| 1 | Logo_WEEE | Symbol:WEEE-Logo_5.6x8mm_SilkScreen | LOGO4 |
| 1 | MIC5504-3.3YM5 | Package_TO_SOT_SMD:SOT-23-5 | U1 |
| 1 | NetTie_2 | NetTie:NetTie-2_SMD_Pad0.5mm | NT1 |
| 1 | PKMCS0909E4000 | Buzzer_Beeper:Buzzer_Murata_PKMCS0909E | BZ1 |
| 1 | SKHHLQA010 | Button_Switch_THT:SW_Tactile_SPST_Angled_PTS645Vx58-2LFS | SW1 |
| 1 | SSM-104-L-SV | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical_SMD_Pin1Right | J2 |
| 1 | TSOP4838 | OptoDevice:Vishay_MOLD-3Pin | U4 |
Questions
How big is the FM3 mainboard PCB?
It measures 32 × 61.5 mm and has 2 copper layers, 1.6 mm thick.
What parts does the FM3 mainboard use?
54 parts, built around the MIC5504-3.3YM5, TSOP4838, SFH 4045N and FC68125. 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 FM3 mainboard KiCad files?
From the asterics/FLipMouse repository on GitHub, at the commit this page was made from: the board is Hardware/PCB-design/mainboard/FM3_mainboard.kicad_pcb and its schematic Hardware/PCB-design/mainboard/FM3_mainboard.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the FM3 mainboard design in my own project?
Its repository states no licence, so its author keeps all rights: ask asterics before reusing the design.
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