DIY HOTAS Sidestick V1

Built from furniture scrap destined for bonfire. Painted with leftover wall paint. Zero budget. Zero special tools.

This sidestick was hand-carved from wooden furniture scraps using large carpentry tools — the same ones used to build beds and wardrobes. The enclosure was painted with leftover grey and black house paint. No 3D printer. No CNC. No fresh materials. Every cut, every curve, every hole was made by hand in a carpenter's workshop.

The electronics inside are a $2 STM32 Blue Pill running custom USB HID firmware — plug it into any Windows PC and it shows up as a native joystick. No drivers. No vJoy. No software installation. Just plug and fly.

Real engineering is not about having the best tools. It's about solving problems with what's available.

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Demo Videos

Video	Description
	HOTAS in action — gameplay short
	Build process short
	Working in FlightGear flight simulator
	Working in War Thunder combat flight sim
	All 4 axes and 10 buttons verified
	Raw wood carving and construction

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Build Photos

Photo	Description
	Finished sidestick — grey/black leftover furniture paint
	Front perspective showing ergonomic grip angle
	Side profile — pinky hook and trigger guard visible
	Blue Pill STM32 and wiring inside the base
	Button and switch wiring closeup
	Before paint — hand-carved wooden grip
	Blue Pill mounted on zero board in base

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Overview

Property	Value
MCU	STM32F103C8T6 (Blue Pill) — $2
Enclosure	Hand-carved furniture scrap wood
Paint	Leftover grey/black house paint
Firmware	STM32 HAL (CubeIDE)
USB	Native HID joystick — no vJoy, no drivers
Analog Axes	4 (2 gimbal + 2 ministick)
Digital Buttons	10
HID Report	10 bytes
Polling Rate	100 Hz
Total Cost	~$5 (salvaged materials)

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Physical Design

Sidestick style — inspired by F-35, Rafale, Typhoon real aircraft grips.

What Was Built by Hand

• Grip — Carved from furniture scrap wood using large hand tools
• Pinky hook — Bottom curve for grip security during intense maneuvers
• Trigger guard — Index finger rest with single stage trigger
• Thumb platform — Top surface with ministick and button layout
• Hat switch housing — M-seal (epoxy putty) molded into cross pattern for 4-directional hat

What Was Painted

• Full grip painted grey and black using leftover house paint
• Multiple coats for durability
• Brush-applied — no spray equipment

What Was Salvaged

• STM32 Blue Pill — from old project inventory
• PS2 joystick module — from spare parts box
• Potentiometers — 10k, reused from previous builds
• Tactile buttons — standard 6mm, bulk purchased
• Type-C breakout — spare module from drawer
• Berg strip connectors — cut from longer strips
• Zero board — for mounting Blue Pill in base

Modular Design

• Blue Pill mounted on zero board in base — pull out and reuse in other projects
• Berg strip connector interface — handle wires plug into base
• Same STM32 can be flashed with different firmware and reinserted
• Base designed for easy wire management

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Electronics

Pin Mapping

Analog Axes

STM32 Pin	ADC Channel	Component	Calibration
PA0	IN0	10k potentiometer — Gimbal X	min=1450, max=2995
PA1	IN1	10k potentiometer — Gimbal Y	min=770, max=1950
PA6	IN6	PS2 thumb ministick X	Raw (no calibration)
PA7	IN7	PS2 thumb ministick Y	Raw (no calibration)

Reserved Analog (Future Expansion)

STM32 Pin	ADC Channel	Planned Use
PA2	IN2	Rudder yaw
PA3	IN3	Left pedal
PA4	IN4	Right pedal
PA5	IN5	Steering wheel

Digital Buttons

STM32 Pin	HID Bit	Button	Location
PB0	Bit 0	PS2 ministick click	Thumb platform
PB3	Bit 1	Trigger	Index finger
PB4	Bit 2	Pinky button	Side of grip
PB5	Bit 3	Red action button	Thumb side
PB6	Bit 4	Hat switch up	Thumb platform (M-seal)
PB7	Bit 5	Hat switch down	Thumb platform (M-seal)
PB8	Bit 6	Hat switch left	Thumb platform (M-seal)
PB9	Bit 7	Hat switch right	Thumb platform (M-seal)
PB11	Bit 8	Up button	Thumb platform
PB12	Bit 9	Down button	Thumb platform

Reserved System Pins

STM32 Pin	Function
PA11	USB D- (Type-C breakout)
PA12	USB D+ (Type-C breakout)
PA13	SWDIO (ST-Link V2)
PA14	SWCLK (ST-Link V2)

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USB Configuration

Property	Value
USB Version	2.0
VID	0x0483 (STMicroelectronics)
PID	0x5723
Max Packet Size	64 bytes
HID Report Size	10 bytes
Polling Interval	10 ms

Note: Onboard micro USB bypassed — data lines faulty on clone board. Type-C breakout module wired directly to PA11, PA12. Fixed USB cable on base panel.

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HID Report Layout

Byte 0-1:  Analog Hat X    (16-bit LE, 0-4095, center ~1500)
Byte 2-3:  X Axis          (16-bit LE, 0-4095, calibrated)
Byte 4-5:  Y Axis          (16-bit LE, 0-4095, calibrated)
Byte 6-7:  Z Axis          (16-bit LE, 0-4095, raw)
Byte 8-9:  Rx Axis         (16-bit LE, 0-4095, raw)
Byte 10:   Buttons [0:7]   (8 bits, active-high)
Byte 11:   Buttons [8:9]   (2 bits + 6 padding)

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Firmware

• Framework: STM32 HAL (CubeIDE)
• USB: Native HID joystick — no vJoy, no drivers needed
• ADC: Software channel switching, 12-bit resolution
• Buttons: GPIO with internal pull-up, active-low
• Calibration: Per-axis min/max mapping in firmware
• Axis inversion: Handled in firmware per axis

Calibration Values

Axis	Pin	Min	Max	Inverted
Gimbal X	PA0	1450	2995	No
Gimbal Y	PA1	770	1950	Yes

Programming

• ST-Link V2 via SWD — no BOOT0 jumper changes needed
• STM32CubeIDE + HAL framework
• Custom USB HID descriptor in usbd_hid.c

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Tested and Working On

• Windows Device Manager — shows as "STM32 Human Interface"
• joy.cpl — all axes and buttons confirmed
• Gamepad tester online
• FlightGear flight simulator
• War Thunder

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Project Structure

HOTAS_Joystick/
├── Core/
│   ├── Inc/          # Header files
│   └── Src/          # Main firmware (main.c)
├── USB_DEVICE/       # USB HID stack
├── Drivers/          # STM32 HAL drivers
├── Middlewares/      # USB middleware
├── firmware/         # Compiled .elf/.bin (future)
├── media/            # Photos and videos
├── docs/             # Additional documentation
├── HOTAS_Joystick.ioc  # CubeMX project config
└── README.md

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What's Next

• V2 — Refined grip, modular handle with berg connector, same gimbal reused
• Rudder pedals — PA2, PA3, PA4 already reserved
• Steering wheel expansion — PA5 reserved
• Drone GCS mode — UART output planned in future firmware

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Build Philosophy

This project proves a fully functional USB HID joystick can be built from workshop scrap, leftover paint, and determination. Every component was salvaged, borrowed, or repurposed. The only investment was time and creativity.

If you have hands and a problem to solve, you already have everything you need.

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License

MIT License — Use freely, build your own, share what you make.