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Kelvin (Revision B)

The Aerium Kelvin is an advanced carrier board engineered to unlock the full potential of the Raspberry Pi Compute Module 5 (CM5) in compact, performance-driven systems. Designed for unmanned platforms and embedded computing applications, Kelvin combines robust processing capabilities with a broad connectivity suite in a lightweight, space-efficient form factor.

Kelvin Kelvin

General​

  • The Kelvin introduces a powerful, yet efficient and compact edge computing solution based on Raspberry pi compute modules.
  • Kelvin introduces rich set of interfaces while maintain small footprint and minimal weight.
  • The board is especially designed for unmanned systems and other space and volume constrained implementations.

Compatibility​

  • The Kelvin introduces a powerful, yet efficient and compact edge computing solution based on Raspberry pi compute modules:

    • Raspberry Pi Compute Module 5 (EMMC versions only)
    • Note: since Pi CM4 and Pi CM5 are mostly similar there is also partial compatibility to Pi CM4

Resources​

Mechanical​

  • Weight

    • Empty weight (w/o Compute Module): ~14 [g].
    • Raspberry pi weight (w/o heatsink): ~8 [g].
    • Heatsink: ~50 [g].
    • Total Weight: ~72 [g].

  • Dimensions

    • Board dimensions are defined in millimeters.
    • Mounting hole size is M2.5.

    Kelvin-dimensions

Electrical​

General​

  • For each connector specification, the pinout orientation is determined by an arrow pointing to pin 1.

Specifications​

  • Input voltage: 8-60 [V]

  • GPIO / Communication logic level: 3.3 [V]

    • Warning: do not operate at any other logic voltage level.

  • Top View kelvin-top

  • Bottom View kelvin-bottom

Electrical pinout​

  • Connector orientation

    • JST-GH cables shall be oriented according to the illustration Kelvin-main-connector

FRC Button​

frc-button

  • To flash Raspberry pi compute module, use the FRC button according to the following steps:
    • Power off the board
    • hold the FRC button
    • Power up the board
    • release the FRC button
    • The Raspberry pi compute modules is now in recovery mode
    • run the script on the host pc to enable flashing

Power​

GH-6P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM06B-GHS-TBTJST-GH
    Cable ConnectorGHR-06V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1VINVoltage Input8V - 60V
    2VINVoltage Input8V - 60V
    3VINVoltage Input8V - 60V
    4GNDGroundGND
    5GNDGroundGND
    6GNDGroundGND

USB OTG​

GH-4P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-GHS-TBJST-GH
    Cable ConnectorGHR-04V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1OTG 5V Power InputUSB OTG Power Supply5V
    2USB0_D-USB Data Minus3.3V
    3USB0_D+USB Data Plus3.3V
    4GNDGroundGND

USB1​

GH-4P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-GHS-TBJST-GH
    Cable ConnectorGHR-04V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputUSB Power Supply5V
    2USB0_D-USB Data Minus3.3V
    3USB0_D+USB Data Plus3.3V
    4GNDGroundGND

USB2​

GH-4P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-GHS-TBJST-GH
    Cable ConnectorGHR-04V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputUSB Power Supply5V
    2USB0_D-USB Data Minus3.3V
    3USB0_D+USB Data Plus3.3V
    4GNDGroundGND

USB3​

GH-8P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM08B-GHS-TBJST-GH
    Cable ConnectorGHR-08V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputUSB Power Supply5V
    2USB_D_N (USB2.0)USB 2.0 Data Minus3.3V
    3USB_D_P (USB2.0)USB 2.0 Data Plus3.3V
    4USBSS_TX_NSuperSpeed TX Minus3.3V
    5USBSS_TX_PSuperSpeed TX Plus3.3V
    6USBSS_RX_NSuperSpeed RX Minus3.3V
    7USBSS_RX_PSuperSpeed RX Plus3.3V
    8GNDGroundGND

USB4​

GH-8P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM08B-GHS-TBJST-GH
    Cable ConnectorGHR-08V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputUSB Power Supply5V
    2USB_D_N (USB2.0)USB 2.0 Data Minus3.3V
    3USB_D_P (USB2.0)USB 2.0 Data Plus3.3V
    4USBSS_TX_NSuperSpeed TX Minus3.3V
    5USBSS_TX_PSuperSpeed TX Plus3.3V
    6USBSS_RX_NSuperSpeed RX Minus3.3V
    7USBSS_RX_PSuperSpeed RX Plus3.3V
    8GNDGroundGND

UART0 + PWM​

GH-6P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM06B-GHS-TBJST-GH
    Cable ConnectorGHR-06V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputPower Supply5V
    2UART0_TXUART0 Transmit3.3V
    3UART0_RXUART0 Receive3.3V
    4PWM0_0 / UART4_TXPWM0_0 or UART4 TX3.3V
    5PWM0_1 / UART4_RXPWM0_1 or UART4 RX3.3V
    6GNDGroundGND

UART1​

GH-4P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-GHS-TBJST-GH
    Cable ConnectorGHR-04V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputPower Supply5V
    2UART2_TXDUART2 Transmit3.3V
    3UART2_RXDUART2 Receive3.3V
    4GNDGroundGND

Ethernet​

GH-8P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM08B-GHS-TBJST-GH
    Cable ConnectorGHR-08V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1ETH_MDI0_PEthernet Pair 0 Positive-
    2ETH_MDI0_NEthernet Pair 0 Negative-
    3ETH_MDI1_PEthernet Pair 1 Positive-
    4ETH_MDI1_NEthernet Pair 1 Negative-
    5ETH_MDI2_PEthernet Pair 2 Positive-
    6ETH_MDI2_NEthernet Pair 2 Negative-
    7ETH_MDI3_PEthernet Pair 3 Positive-
    8ETH_MDI3_NEthernet Pair 3 Negative-

CAN​

GH-4P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-GHS-TBJST-GH
    Cable ConnectorGHR-04V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputPower Supply5V
    2CAN_HCAN High3.3V
    3CAN_LCAN Low3.3V
    4GNDGroundGND

I2C​

GH-6P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM06B-GHS-TBTJST-GH
    Cable ConnectorGHR-06V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputPower Supply5V
    2I2C0_SCLI2C0 Serial Clock3.3V
    3I2C0_SDAI2C0 Serial Data3.3V
    4I2C1_SCLI2C1 Serial Clock3.3V
    5I2C1_SDAI2C1 Serial Data3.3V
    6GNDGroundGND

SPI​

GH-06P

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM06B-GHS-TBTJST-GH
    Cable ConnectorGHR-06V-SJST-GH

  • Connector Pinout

    PinNameDescriptionVoltage
    1Power OutputPower Supply5V
    2SPI0_SCLKSPI Serial Clock3.3V
    3SPI0_MISOSPI Master In Slave Out3.3V
    4SPI0_MOSISPI Master Out Slave In3.3V
    5SPI0_CS0_NSPI Chip Select 03.3V
    6GNDGroundGND

CAM0 (MIPI-CSI)​

CSI

  • Connector Definition

    TypePart Number
    Board ConnectorSFV15R-1STBE1HLF
    Cable ConnectorFFC 15 PIN 0.5mm pitch

  • Connector Pinout

    PinNameDescriptionVoltage
    1GNDGroundGND
    2CSI0_D0_NCamera Data Lane 0 Negative1.2V
    3CSI0_D0_PCamera Data Lane 0 Positive1.2V
    4GNDGroundGND
    5CSI0_D1_NCamera Data Lane 1 Negative1.2V
    6CSI0_D1_PCamera Data Lane 1 Positive1.2V
    7GNDGroundGND
    8CSI0_CLK_NCamera Clock Negative1.2V
    9CSI0_CLK_PCamera Clock Positive1.2V
    10GNDGroundGND
    11CAM0_PWDNCamera Power Down3.3V
    12CAM0_MCLKCamera Master Clock3.3V
    13CAM0_SCLCamera I2C Serial Clock3.3V
    14CAM0_SDACamera I2C Serial Data3.3V
    153.3VPower Supply3.3V

CAM1 (MIPI-CSI)​

CSI

  • Connector Definition

    TypePart Number
    Board ConnectorSFV15R-1STBE1HLF
    Cable ConnectorFFC 15 PIN 0.5mm pitch

  • Connector Pinout

    PinNameDescriptionVoltage
    1GNDGroundGND
    2CSI2_D0_NCamera Data Lane 0 Negative1.2V
    3CSI2_D0_PCamera Data Lane 0 Positive1.2V
    4GNDGroundGND
    5CSI2_D1_NCamera Data Lane 1 Negative1.2V
    6CSI2_D1_PCamera Data Lane 1 Positive1.2V
    7GNDGroundGND
    8CSI2_CLK_NCamera Clock Negative1.2V
    9CSI2_CLK_PCamera Clock Positive1.2V
    10GNDGroundGND
    11CAM1_PWDNCamera Power Down3.3V
    12CAM1_MCLKCamera Master Clock3.3V
    13CAM1_SCLCamera I2C Serial Clock3.3V
    14CAM1_SDACamera I2C Serial Data3.3V
    153.3VPower Supply3.3V

PCIe​

PCIe

  • Connector Definition

    TypePart Number
    Board ConnectorSFV16R-1STBE1HLF
    Cable ConnectorFFC 16 PIN 1.0mm pitch

  • Connector Pinout

    PinNameDescriptionVoltage
    15VPower Supply5V
    25VPower Supply5V
    3GNDGroundGND
    4PCIE_CLK_PPCIe Clock Positive1.2V
    5PCIE_CLK_NPCIe Clock Negative1.2V
    6GNDGroundGND
    7PCIE_RX_PPCIe Receiver Positive1.2V
    8PCIE_RX_NPCIe Receiver Negative1.2V
    9GNDGroundGND
    10PCIE_TX_PPCIe Transmit Positive1.2V
    11PCIE_TX_NPCIe Transmit Negative1.2V
    12GNDGroundGND
    13PCIE_PWR_ENPCIe Power Enable3.3V
    14PCIE_DET_WAKEPCIe Detect / Wake3.3V
    15PCIE_CLKREQ_NPCIe Clock Request3.3V
    16PCIE_RST_BPCIe Reset3.3V

RTC​

rtc-connector

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM02B-SRSS-TBJST SH 1.0 mm SMT Side-Entry Header
    Cable HousingSHR-02V-SJST SH 2-Circuit Receptacle Housing
    Crimp TerminalSSHL-002T-P0.2JST SH Crimp Contact (AWG 32–28)

  • Connector Pinout

    Note: This pinout is non-standard and was designed to match the official Raspberry Pi 5 RTC battery connector
    PinName
    1GND
    2RTC Power Input

FAN​

FAN-connector

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorSM04B-SRSS-TBJST SH 1.0 mm SMT Side-Entry Header
    Cable HousingSHR-04V-SJST SH 4-Circuit Receptacle Housing
    Crimp TerminalSSHL-004T-P0.2JST SH Crimp Contact (AWG 32–28)

  • Connector Pinout

    PinName
    15v
    2PWM
    2GND
    2TACHO

SD-Card​

  • General
    • The SD card slot is for storage only and doesn’t support flashing an operating system.

Software​

General​

  • The software installation for the Kelvin board is simple and based on the same steps as the Dev Kit board.

Flashing Raspbian OS​

Serial Port Mapping and Configuration​

Physical Port NameLinux Device NameCM5 GPIOCM5 UART NameRequired Overlay
UART0/dev/ttyAMA0RX: 15 TX: 14UART0uart0-pi5
UART0/dev/ttyAMA4RX: 13 TX: 12UART4uart4-pi5
UART1/dev/ttyAMA2RX: 5 TX: 4UART2uart2-pi5

Enabling UART0 and UART1 ports on Raspberry Pi CM5​

  • Step 1: Power off the Raspberry Pi CM5 board.
  • Step 2: Mount the /boot/firmware partition of the eMMC.
  • Step 3: Open the file /boot/firmware/config.txt.
  • Step 4: Add the following lines at the end of the file: 
    dtoverlay=uart0-pi5
    dtoverlay=uart2-pi5
    dtoverlay=uart4-pi5
    NOTE: uart4 will be used on the PWM pins on port UART0
  • Step 5: Reboot the board.

Adding Static IP Configuration to Raspberry Pi CM5​

  • Step 1: Power off the Raspberry Pi CM5 board.
  • Step 2: Mount the /boot/firmware partition of the eMMC.
  • Step 3: Open the file /boot/firmware/cmdline.txt.
  • Step 4: Locate the single long line of kernel parameters (do not add line breaks).
  • Step 5: Append the following to the end of that line, separated by a space: 
    ip=192.168.55.10::192.168.1.1:255.255.255.0::eth0:off
  • Step 5: Reboot the board.

Enabling Dual MIPI IMX219 Cameras on Raspberry Pi CM5​

  • Step 1: Power off the Raspberry Pi CM5 board.
  • Step 2: Mount the /boot/firmware partition of the eMMC.
  • Step 3: Open the file /boot/firmware/config.txt (or usercfg.txt if your OS expects custom edits there).
  • Step 4: Add the following lines at the end of the file: 
    # Enable camera firmware support
    start_x=1
    gpu_mem=256

    # Enable dual IMX219 cameras (Pi Camera V2 modules)
    dtoverlay=imx219,cam0
    dtoverlay=imx219,cam1
  • Step 5: Reboot the board.

Enabling CAN interface on Raspberry Pi CM5​

  • The MCP2515 is connected to SPI1 with CS0 (GPIO18) on the CM5.
  • Step 1: Power off the Raspberry Pi CM5 board.
  • Step 2: Mount the /boot/firmware partition of the eMMC.
  • Step 3: Open the file /boot/firmware/config.txt
  • Step 4: Add the following line to the end of the file: 
    dtparam=spi=on
    dtoverlay=spi1-1cs
    dtoverlay=mcp2515,spi1-0,oscillator=8000000,interrupt=25
  • Step 5: Reboot the board.