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Kelvin

The Kelvin is a high-performance Raspberry Pi CM5 carrier board engineered for robotics, drones, and embedded systems that demand compactness, speed, and robust connectivity.

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 robots, UAVs 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

    PinName
    1VIN
    2VIN
    3VIN
    4GND
    5GND
    6GND

USB OTG​

GH-4P

  • Connector Definition

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

  • Connector Pinout

    PinName
    1OTG 5V Power Input
    2USB0_D-
    3USB0_D+
    4GND

USB1​

GH-4P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2USB0_D-
    3USB0_D+
    4GND

USB2​

GH-4P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2USB0_D-
    3USB0_D+
    4GND

USB3​

GH-8P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2USB_D_N (USB2.0)
    3USB_D_P (USB2.0)
    4USBSS_TX_N
    5USBSS_TX_P
    6USBSS_RX_N
    7USBSS_RX_P
    8GND

USB4​

GH-8P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2USB_D_N (USB2.0)
    3USB_D_P (USB2.0)
    4USBSS_TX_N
    5USBSS_TX_P
    6USBSS_RX_N
    7USBSS_RX_P
    8GND

UART0 + PWM​

GH-6P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2UART0_TX
    3UART0_RX
    2PWM0_0
    3PWM0_1
    4GND

UART1​

GH-4P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2UART2_RXD (logic 3.3v)
    3UART2_TXD (logic 3.3v)
    4GND

Ethernet​

GH-8P

  • Connector Definition

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

  • Connector Pinout

    PinName
    1ETH_MDI0_P
    2ETH_MDI0_N
    3ETH_MDI1_P
    4ETH_MDI1_N
    5ETH_MDI2_P
    6ETH_MDI2_N
    7ETH_MDI3_P
    8ETH_MDI3_N

CAN​

GH-4P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2CAN_H (logic 3.3v)
    3CAN_L (logic 3.3v)
    4GND

I2C​

GH-6P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2I2C0_SCL (logic 3.3v)
    3I2C0_SDA (logic 3.3v)
    4I2C1_SCL (logic 3.3v)
    5I2C1_SDA (logic 3.3v)
    6GND

SPI​

GH-06P

  • Connector Definition

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

  • Connector Pinout

    PinName
    15V Power Output
    2SPI0_SCLK (logic 3.3v)
    3SPI0_MISO (logic 3.3v)
    4SPI0_MOSI (logic 3.3v)
    5SPI0_CS0_N (logic 3.3v)
    6GND

CAM0 (MIPI-CSI)​

CSI

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorFH12-15S-0.5SH-
    Cable ConnectorFFC 15 PIN 0.5mm pitch-

  • Connector Pinout

    PinName
    1GND
    2CSI0_D0_N
    3CSI0_D0_P
    4GND
    5CSI0_D1_N
    6CSI0_D1_P
    7GND
    8CSI0_CLK_N
    9CSI0_CLK_P
    10GND
    11CAM0_PWDN
    12CAM0_MCLK
    13CAM0_SCL
    14CAM0_SDA
    153.3V

CAM1 (MIPI-CSI)​

CSI

  • Connector Definition

    TypePart NumberPart Name
    Board ConnectorFH12-15S-0.5SH-
    Cable ConnectorFFC 15 PIN 0.5mm pitch-

  • Connector Pinout

    PinName
    1GND
    2CSI2_D0_N
    3CSI2_D0_P
    4GND
    5CSI2_D1_N
    6CSI2_D1_P
    7GND
    8CSI2_CLK_N
    9CSI2_CLK_P
    10GND
    11CAM1_PWDN
    12CAM1_MCLK
    13CAM1_SCL
    14CAM1_SDA
    153.3V

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​

Port NameDevice NameRequired Overlay
UART0/dev/AMA0uart0-pi5
UART1/dev/AMA2uart2-pi5

Enabling UART0 and UART2 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: 
    enable_uart=1
    dtoverlay=uart0-pi5
    dtoverlay=uart2-pi5

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

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