Hardware Compatibility Matrix¶

This page provides a comprehensive compatibility matrix for different hardware combinations with Calculinux.

SBC Compatibility¶

SBC Model	Status	RAM Options	Notes
Luckfox Lyra	✅ Fully Supported	128 MB	Primary platform
Luckfox Lyra (SPI NAND)	✅ Supported	128 MB	Requires NAND erase
Luckfox Lyra Plus	❓ Unknown	128 MB	RK3506-based with Ethernet (untested)
Milk-V Duo	🚧 Planned	64 MB	Future support
Milk-V Duo256	🚧 Planned	256 MB	Future support
Raspberry Pi Zero	❌ Not Compatible	N/A	Form factor mismatch
Custom Boards	❓ Unknown	Varies	Community experiments

Legend: - ✅ Fully Supported - Works out of box with official images - 🚧 Planned - Under development or planned for future - ❓ Unknown - Not tested, may work with modifications - ❌ Not Compatible - Known not to work

Luckfox Lyra Variants¶

Supported Variants¶

Calculinux currently supports the Luckfox Lyra board with 128 MB RAM:

RAM	Storage	Status	Notes
128 MB	SD Card Only	✅ Recommended	Simplest setup
128 MB	SPI NAND + SD	✅ Supported	Requires NAND erase first

Other Lyra Models

Luckfox Lyra Plus: RK3506-based with Ethernet (untested with Calculinux)
256 MB Lyra variants: Would require custom adapter boards due to different pinouts; community members are experimenting with this

By Storage Type¶

Storage	Boot Priority	Calculinux Support
SD Card Only	Primary	✅ Recommended - simplest setup
SPI NAND + SD	NAND first	✅ Supported after NAND erase

By Network Capability¶

Limited Network Options

The basic Luckfox Lyra has no built-in networking. The Luckfox Lyra Plus with Ethernet would require a custom 3D-printed backplate to access the port and has not been tested with Calculinux. USB WiFi adapters are the only tested networking option.

Connectivity	Hardware Required	Status	Notes
Luckfox Lyra Plus (Ethernet)	Custom backplate	❓ Untested	Plus model has Ethernet but not tested
USB WiFi	USB WiFi adapter (3.3V or powered hub)	✅ Supported	Only tested networking option

Storage Compatibility¶

MicroSD Cards¶

Brand/Type	Speed Class	Size	Status	Notes
SanDisk Ultra	Class 10	8-32 GB	✅ Recommended	Good reliability
Samsung EVO	Class 10	8-32 GB	✅ Recommended	Good value
Generic/No-Name	Varies	Any	⚠️ Use Caution	May be unreliable

Recommendations: - Minimum: 8 GB Class 10 - Recommended: 16-32 GB from reputable brand

SD Card Performance

Given the hardware speeds, different SD card classes are unlikely to have significant impact on performance.

PicoCalc External SD Card Slot¶

Type	Status	Notes
Internal Lyra Storage	✅ Fully Supported	Main SD card and optional SPI NAND
PicoCalc SD Card Slot	✅ Supported	Accessible external SD card slot on PicoCalc for additional storage
External USB Storage (OTG)	🧪 Experimental	Via Lyra's USB-C port with 3.3V devices or powered hub

USB-C OTG Support

The Lyra's USB-C port supports USB On-The-Go functionality, enabling connection of external USB storage devices. However, this requires 3.3V compatible devices or an externally powered USB hub. This feature is currently experimental and may require additional configuration.

Display Compatibility¶

Integrated Display¶

PicoCalc Model	Display Type	Status
PicoCalc	ILI9488 LCD	✅ Fully Supported

Replacement Display Options¶

Display Type	Connector	Size Requirement	Status
MIPI DSI (Higher Resolution)	22-pin (CM4 compatible)	3.95" diagonal, square	🚧 Possible
Original ILI9488	SPI	320×320	✅ Standard

MIPI DSI Display Upgrade

Higher resolution MIPI DSI displays are possible if they use the same 22-pin connector found on Raspberry Pi Compute Module IO boards. The display must be square format and exactly 3.95" diagonal to fit within the PicoCalc enclosure. This would require hardware modification and custom driver configuration.

Input Device Compatibility¶

Integrated Keyboard¶

PicoCalc Model	Keyboard	Status
All Models	Matrix Keyboard	✅ Fully Supported

External Input¶

Device Type	Connection	Status	Notes
USB Input Devices	USB-C OTG	🧪 Experimental	Requires 3.3V devices or powered hub
Keyboard/Mouse	USB-C OTG	🧪 Experimental	May work with compatible devices

USB OTG Input Support

While the integrated matrix keyboard is the primary input method, external USB input devices may be possible via the USB-C OTG port. This requires 3.3V compatible devices or an externally powered USB hub and is currently untested.

Network Hardware¶

Built-in Network¶

Model	Interface	Speed	Status
Lyra Plus	Ethernet (10/100)	100 Mbps	❓ Untested - Requires custom backplate
Lyra	None	N/A	N/A - USB WiFi adapters supported

Network Options

Luckfox Lyra: No built-in networking. USB WiFi adapters (3.3V or via powered hub) are the only networking option.
Luckfox Lyra Plus: Has built-in Ethernet but has not been tested with Calculinux and would require a custom 3D-printed backplate to access the Ethernet port within the PicoCalc enclosure.

Power Supply Compatibility¶

Internal Battery Power¶

Power Source	Status	Notes
PicoCalc Internal Battery	✅ Fully Supported	Rechargeable lithium-ion
PicoCalc USB-C Port	✅ Supported	Battery charging + serial console to Lyra
Lyra USB-C Port	✅ Supported	USB-OTG data only (does NOT charge PicoCalc)

Two USB-C Ports

The PicoCalc has TWO USB-C ports with different functions:

PicoCalc USB-C Port: Used for charging the internal battery and provides a USB serial console connection to the Lyra (at 1500000 baud)
Lyra USB-C Port: Provides USB On-The-Go (OTG) functionality for external devices but does NOT charge the PicoCalc batteries. External devices must be 3.3V compatible or use an externally powered hub.

Peripheral Compatibility¶

Internal Peripherals¶

Device Type	Status	Notes
Display	✅ Fully Supported	Integrated LCD
Keyboard	✅ Fully Supported	Matrix keyboard
Lyra Storage	✅ Fully Supported	Lyra's SD card, optional NAND
PicoCalc SD Card Slot	✅ Fully Supported	External SD card accessible on PicoCalc

Expansion Interfaces¶

Internal Expansion Options

While the Luckfox Lyra is enclosed within the PicoCalc, it provides several expansion interfaces accessible for hardware modifications and custom projects. For detailed pinout information, see the official Luckfox Lyra pinout documentation.

Interface	Voltage	Status	Notes
GPIO	3.3V	✅ Available	External GPIO pins are free (display/keyboard do not use them)
USB	3.3V	✅ Available	Internal USB host/device
I2C	3.3V	✅ Available	I2C bus for sensors/peripherals
I2S	3.3V	❓ Untested	Audio interface available but untested
SPI	3.3V	✅ Available	SPI interface (shared with display)
UART	3.3V	✅ Available	Serial communication

3.3V Logic Level Requirement

CRITICAL: All interfaces operate at 3.3V logic levels only. Using 5V devices or signals will damage the hardware. The PicoCalc is designed for tinkering and experimentation, but proper voltage levels must be maintained.

Expansion Peripheral Compatibility¶

Peripheral Type	Interface	Status	Notes
Sensors	I2C/SPI	✅ Compatible	Temperature, accelerometer, etc.
External Storage	USB 3.3V	✅ Compatible	Flash drives, custom storage
Network Modules	USB/SPI	🚧 Possible	WiFi/cellular modules (3.3V)
Audio Devices (I2S)	I2S	❓ Untested	External audio codecs via I2S interface
Audio Devices (PWM)	GPIO (PWM)	⚠️ Limited	See PWM audio note below
Replacement Displays	MIPI DSI	🚧 Possible	22-pin connector, 3.95" square
Additional SPI Displays	SPI	⚠️ Conflicts	Would conflict with main display
Input Devices	GPIO/I2C	🚧 Possible	Additional buttons, encoders
Communication	UART/USB	✅ Compatible	Serial devices, modems

PWM Audio Details

The PicoCalc has built-in audio support using PWM (Pulse Width Modulation) on GPIO pins. However, there are significant limitations:

The Lyra's PWM is not available on the correct pins without hardware modification
Software PWM must be used instead on pins with only 1.2V tolerance
This results in low volume audio and high CPU usage

For proper audio, hardware modifications are needed to access the correct PWM pins or use the I2S interface. See the Hardware Modifications guide for details on enabling full-volume audio (documentation stub - refer to the ClockworkPi forum for community solutions).

Custom Hardware Projects

These expansion options enable custom hardware projects and modifications for advanced users comfortable with electronics work.

Software Compatibility¶

Console-Only System

Calculinux is currently a console-only system with no graphical desktop environment. All interaction is via text terminal. This is by design to maximize performance on limited hardware (128 MB RAM).

Console Applications¶

All console applications work well with the 128 MB RAM configuration:

Application Type	Status	Notes
Terminal Apps	✅ Fully Supported	All work well
Text Editor (vim/nano)	✅ Fully Supported	All work well
Scripting (Python/Bash)	✅ Fully Supported	All work well
Development Tools	✅ Fully Supported	All work well
Command-line Tools	✅ Fully Supported	All work well

Gaming and Entertainment (Community Tested)¶

Community Testing Results

These applications have been tested by community members but may not be included in official Calculinux images.

Application	Status	Notes
Pico-8	✅ Working	Runs smoothly, audio requires hardware mod
Doom (prboom)	✅ Working	Good performance, tested extensively
RetroArch	⚠️ Issues	Has configuration problems
tmux	✅ Working	Terminal multiplexer works well
Framebuffer apps	✅ Working	FBV image viewer confirmed working

Gaming Performance

Gaming applications work but are limited by SPI display bandwidth. Not all emulators perform well due to hardware constraints.

Testing Status¶

Tested Configurations¶

Configuration	Test Date	Status
Lyra 128MB + 64GB SD	Mar 2025	✅ Working

Known Issues¶

Issue	Affected Hardware	Status	Workaround
SPI NAND Boot	Lyra with NAND	✅ Documented	Erase NAND first
Slow SD Cards	External SD card	⚠️ Known	Use internal storage for demanding tasks

Community Testing¶

We need community help testing various hardware combinations!

Untested Configurations¶

Help us test these combinations:

[ ] Different SD card brands (though performance differences are likely minimal)
[ ] Various applications (request inclusion!)
[ ] Luckfox Lyra Plus (Ethernet model) with custom backplate

How to Report¶

If you test a configuration:

Open an issue on GitHub
Include:
Hardware model and version
SD card brand and size
Any peripherals connected
What works / doesn't work
Use the "Hardware Compatibility Report" template