DeskPi Mini Cube

• New Product: ⭐⭐⭐⭐⭐
• Compability: ⭐⭐⭐⭐
• Mobility: ⭐⭐⭐⭐⭐
• Assemble Difficulty: ⭐

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DeskPi Mini Cube

Description

DeskPi Mini Cube for Raspberry Pi CM4 is a case with a miniature appearance and extremely portable features.

Note: Only supports Raspberry Pi CM4 module

The device provides a mini aluminum alloy radiator and integrates a silent fan that supports PWM speed regulation.

The bottom board provides a wealth of interfaces, supporting dual full-size HDMI interfaces, RJ45 Ethernet interfaces, 2x OTG USB port, and one PCIe interface supports M.2 NVME SSD M-KEY 2242 external storage.

The DIP switch on the back provides the special pins needed to configure the Raspberry Pi CM4 module. (On Compute Module 4 EMMC-DISABLE / nRPIBOOT (GPIO 40) must be fitted to switch the ROM to usbboot mode.)

Otherwise, the SPI EEPROM bootloader image will be loaded instead.

The 40Pin GPIO lead out and reserved RTC clock battery interface.

Features

• Integrated design
• Aluminum alloy radiator with PWM adjustable speed fan
• Power button
• 2 x Full-size HDMI ports
• 2 x OTG USB2.0 port
• 1 x PCIe M.2 NVME M-KEY 2242 SSD slot
• 1 x 40 Pin GPIO lead out
• 1 x DIP switch for mode change (CM4 function change)
• 1 x Onboard PCF85063 I2C RTC module
• 5V USB-C Port Power IN

Gallery

• Product Outlook

• Backside of Mini Cube

• Ports Definitions

• Inside of Mini Cube
  

• Dimension

• IPX antenna specifications

  • Centre Frequency: 2400-2500MHz & 4900-5900MHz
  • Connector: IPEX1
  • Lead Length:
  • Antenna Element Length: mm (+/- 1mm)
  • Antenna Element Cable: 1.13 Coaxial cable, with plastic coating.
  • Impedance: 5Ohm.
  • Gain: About 3 dBi.

Install IPEX Antenna

Add the antenna as following figure, and then remove the protection film on back of the antenna, and then paste it inside the case.

RTC Battery Information

ear RTC Battery dose not include in the package, additional purchase required! * Fit for: laptop CMOS Battery, Recommended CR1220 3V with ZH1.25 Connector.

Package Includes

• 1 x DeskPi Mini Cube for Raspberry Pi computer module 4

How to assemble it

• Step 1. Unloose four screws on top of mini cube.
• Step 2. Remove copper pillar and paste thermal pad on top of Raspberry Pi CM4 module.

NOTE：Please peel off the protection film on both side of the thermal pad. and press the Raspberry Pi CM4 module according to following figure, please be ware of the direction and angle when press the Raspberry Pi CM4 module.

• Step 3. Fix aluminum heat sink to Raspberry Pi CM4 module with copper pillars.

Please refer to following figure to assemble it.

[Optional] Install M.2 NVME SSD M-KEY 2242/2240.

1. Remove the screws on bottom of mini cube and remove the PCB which is connected to mainboard on 40Pin GPIO.

2. Insert SSD drive into the slot in 45-degree angle and fix it with screw.

3. Cover it back to 40Pin GPIO and make sure it connect properly.

4. Fix the bottom case with screws.

Functionality of power button:

• Short Press: Power on
• Long Press: Power off (Cutoff power)

Please NOTE that if you have not shutdown the system, do not use long press to halt system, it will damage your system, it may cause kernel panic or lost file which are not saved yet.

• Correct Operation: Shutdown system in terminal or desktop, and then long press the button to cut off power.

DIP Switch Functionality

DIP Switch Pinout

• 1 - USB OTG Pull UP
• 2 - UNATTENDEND
• 3 - EEPROM_nWP (EEPROM write protection)
• 4.- nRPIBOOT (disable or enable eMMC Boot)

If you are using Raspberry Pi CM4 with EMMC onboard. please refer to this URL: How to flash the Compute Module in section “Flashing the Compute Module eMMC”

Hardware write-protection must be enabled via software and then locked by pulling the EEPROM_nWP pin low.

How to enable USB2.0 ports besides the USB-C port?

Assume that you are using Raspberry Pi OS (64bit/32bit).

• The latest official image which you can download from: www.raspberrypi.com/software will automatically adding otg_mode=1 in /boot/firmware/config.txt file, so you don't need to modify any parameter in /boot/firmware/config.txt file.

How to Update EEPROM Firmware on Raspberry Pi Compute Module 4 (CM4)

Overview

Unlike earlier Compute Modules, the CM4 uses an EEPROM bootloader stored in on-board storage rather than the boot partition. This means it requires different update procedures compared to standard Raspberry Pi boards.

Prerequisites

Install usbboot (Host PC)

# Clone the official usbboot repository
git clone --depth=1 https://github.com/raspberrypi/usbboot
cd usbboot

# Build (Linux/macOS)
make

# Install dependencies if needed (Debian/Ubuntu)
sudo apt install libusb-1.0-0-dev

Method 1: Flash Bootloader EEPROM via USB (Recommended)

This method directly writes the bootloader EEPROM using rpiboot in recovery mode. It is the most reliable method for CM4.

Step 1: Hardware Setup

1. Mount the CM4 onto the IO Board.
2. Ensure the EEPROM_nWP pin is NOT pulled low (write-protection must be disabled).
3. Connect the IO Board's USB slave port to your host PC.
4. Do NOT insert an SD card or eMMC storage if you want to target the EEPROM directly.
5. Power on the IO Board.

Step 2: Flash the EEPROM

Run the recovery command from the usbboot directory:

cd usbboot
sudo ./rpiboot -d recovery

This writes recovery/pieeprom.bin to the CM4's bootloader EEPROM.

Step 3: Re-enable Write Protection (Optional)

Once flashing completes successfully, you may pull EEPROM_nWP low again to prevent accidental modification.

Method 2: Self-Update from a Running OS

If your CM4 is already booting from eMMC, USB, or network, you can enable self-update mode. However, this method carries a risk.

⚠️ Warning: Self-update mode does not update the bootloader atomically. If a power failure occurs during the EEPROM update, you could corrupt the EEPROM.

Why CM4 Disables rpi-eeprom-update by Default

On CM4, the rpi-eeprom-update service is disabled by default because the eMMC is not removable, and an invalid recovery.bin file could brick the system.

Enable Self-Update

1. Add the following to your config.txt or bootloader configuration:

ENABLE_SELF_UPDATE=1

1. Reboot the CM4. The bootloader will check for updates from the boot media (eMMC, USB MSD, or network boot).

Method 3: Update from Raspberry Pi OS (If Running)

If you have Raspberry Pi OS running on the CM4 and want to check the current EEPROM version:

# Check current EEPROM status
sudo rpi-eeprom-update

# Update to latest stable (only works if self-update is enabled or on supported platforms)
sudo rpi-eeprom-update -a

Note: On some platforms (e.g., Home Assistant Yellow with CM4), firmware updates via rpi-eeprom-update may be blocked with unsupported_boot_device. In such cases, use the rpiboot method instead.

Important Best Practices

Before deploying CM4 in production, Raspberry Pi recommends:

1. Select a specific bootloader release and verify every CM4 has that release.
2. Configure BOOT_ORDER to define the boot device priority (eMMC → USB → NVMe → Network, etc.).
3. Enable hardware write-protection (EEPROM_nWP pulled low) on production units to prevent unauthorized modification.

Example Bootloader Configuration

Create or edit boot.conf before flashing:

[all]
BOOT_UART=0
WAKE_ON_GPIO=1
POWER_OFF_ON_HALT=0
BOOT_ORDER=0xf2641   # eMMC → USB → NVMe → Network → Loop
ENABLE_SELF_UPDATE=1

Then use rpi-eeprom-config to apply it:

sudo rpi-eeprom-config --out pieeprom-new.bin --config boot.conf pieeprom.bin

Troubleshooting

References

• Raspberry Pi Compute Module Documentation
• rpi-eeprom GitHub Releases
• usbboot GitHub Repository

Updating CM4 EEPROM Firmware with DeskPi Mini Cube

DIP Switch Configuration

The DeskPi Mini Cube has a 4-position DIP switch on the back that controls key CM4 signals. Here is the pinout:

Step-by-Step: Flash EEPROM via USB (rpiboot)

1. Set DIP Switches for USB Boot Mode

To put the CM4 into rpiboot mode (required for EEPROM flashing), configure the switches before powering on:

⚠️ Critical: Switch 4 must be ON before power is applied, and switch 3 must be OFF to allow EEPROM writing.

2. Connect Hardware

1. Connect a USB-C cable from the Mini Cube's USB-C port to your host PC (Linux/macOS/Windows).
2. Connect USB-C power to the Mini Cube's power input.
3. Power on the Mini Cube.

3. Run rpiboot on Host PC

On your host computer, clone and run the official usbboot tool:

# Linux / macOS
git clone --depth=1 https://github.com/raspberrypi/usbboot
cd usbboot
make

# Flash the EEPROM with the recovery firmware
sudo ./rpiboot -d recovery

This will write recovery/pieeprom.bin to the CM4's SPI EEPROM.

4. Custom EEPROM Configuration (Optional)

If you want to customize bootloader settings (e.g., BOOT_ORDER), edit recovery/boot.conf first, then regenerate the EEPROM image:

cd recovery
# Edit boot.conf as needed
./update-pieeprom.sh
cd ..
sudo ./rpiboot -d recovery

Step-by-Step: Normal Boot Mode (After Update)

Once the EEPROM is flashed, revert the DIP switches to boot from eMMC or NVMe:

Then power-cycle the Mini Cube.

Troubleshooting

Summary

How to enable fan automatically?

** Assume that your operating system is Raspberry Pi OS (32bit/64bit) **

Official Fan setting

• Open a terminal and typing following command:

sudo raspi-config 

Navigate to Performance Options -> P4 Fan -> Yes -> 14 -> 60 -> yes -> finish -> reboot Raspberry Pi.

The fan is support PWM signal control via GPIO14 which is physical pin 12(TXD), it will spinning when the CPU temperature is above 60 degree.

and also you can write your code to control the fan via GPIO14, sending PWM signal will trigger the fan spinning.

Control Fan manually

Demo code

• Here is a demo code for controlling fan speed by using python script.

 #!/usr/bin/python3

import RPi.GPIO as GPIO
import time
import subprocess

GPIO.setmode(GPIO.BCM)
GPIO.setup(14, GPIO.OUT)
pwm = GPIO.PWM(14,100)

print("\nPress Ctrl+C to quit \n")
dc = 0
pwm.start(dc)

try:
    while True:
        temp = subprocess.getoutput("vcgencmd measure_temp|sed 's/[^0-9.]//g'")
        if round(float(temp)) >= 45:
            dc = 100
            pwm.ChangeDutyCycle(dc)
            print("CPU Temp:",float(temp)," Fan duty cycle:",dc)
            time.sleep(180.0)
        if round(float(temp)) >= 40:
            dc = 85
            pwm.ChangeDutyCycle(dc)
            print("CPU Temp:",float(temp)," Fan duty cycle:",dc)
            time.sleep(120.0)
        else:
            dc = 70
            pwm.ChangeDutyCycle(dc)
            print("CPU Temp:",float(temp)," Fan duty cycle:",dc)
            time.sleep(60.00)

except KeyboardInterrupt:
    pwm.stop()
    GPIO.cleanup()
    print("Ctrl + C pressed -- Ending program")

Then execute it:

python3 fan_control.py

How to enable onboard RTC module?

NOTE:
RTC battery sock type: ZH1.25
The battery dose not include in the package, additional purchase required!! * Step 1. Modify /boot/config.txt file and adding following parameter:

dtoverlay=i2c-rtc,pcf85063a,i2c_csi_dsi,addr=0x51

Save it and please reboot your Raspberry Pi.

• Step 2. Check if RTC module has been recognized by Raspberry Pi. Execute following command in a terminal:

  dmesg |grep i2c 
  

  

  i2cdetect -y 10 
  

  NOTE: if command not found, please install i2c-tools:

  sudo apt update 
  sudo apt upgrade -y 
  sudo apt -y install i2c-tool
  

  

• Step 3. Probe the module rtc-pcf85063 and check the kernel module status.

  modprobe rtc-pcf85063
  lsmod |grep rtc 
  

  

• Step 4. Setting system date and sychronized system time to Hardware clock time.

** Check RTC time in command line.

cat /proc/driver/rtc 

** Setting system time Syntax

date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

sudo date -s 'tue oct 18 08:50:23 BST 2022'
or 
sudo date 053118062023.22 

** Sychronizing system time to HW clock time.

sudo hwclock -w

sudo hwclock ; date

FAQ

• Q: Dose it support NVMe SSD booting?
  A: It has been tested, yes, it supports, but you may need to upgrade eeprom by using rpi-boot from official github repository.