Flight Heritage since 2014

ISIS On Board Computer


  • 400 MHz, power efficient ARM9 processor
  • Multiple OS options available:
  • On-board telemetry: voltages, power-controller, and real time clock
  • High reliability data storage and fail safe filesystem
  • Flexible daughterboard architecture
  • Robust design
  • Includes Hardware Abstraction Layer Library
  • Compliant with CubeSat standard

Option Sheet

Availability: 8 – 12 weeks

  • Description
  • Properties
  • Performance
  • Interfaces
  • Testing
  • Software
  • Daughter Boards
  • In the box


The ISIS On Board computer (IOBC) is a flight-proven, high-performance processing unit based around an ARM9 processor with a speed of 400 MHz, making it one of the most capable on-board computers for CubeSats, currently available on the market within the same price range. Its pluggable daughter board offers additional flexibility and customizability by providing a wide range of extra interfaces for payloads, sensors or actuators in a compact form factor.

  • Operating Temperature: -25 degC to +65 degC
  • Power Supply: 3.3V
  • Dimension: 96 x 90 x 12.4 [mm] (including FM daughter board)
  • Mass: 94g mainboard only, 100g with EM daughter board
  • Power Consumption: 400mW average
  • Processor: 400MHz 32-bit ARM9 processor
  • Volatile Memory: 64MB SDRAM
  • Code Storage: 1MB NOR Flash
  • Critical Data Storage: 512kb FRAM
  • Mass Data Storage: 2 x 2GB high reliability SD cards for fail safe data storage (up to 32 GB on request) or 2x any size standard SD cards
  • I2C master or slave mode
  • SPI master mode up to 8 slaves
  • 2x UART (RS232 + RS232 / RS485 / RS422)
  • General Purpose Input / Output pins (GPIO)
  • ADC: 8 channel, 10-bit
  • PWM: 6 channel
  • JTAG for programming and debugging
  • Dedicated debug LEDs and UART
  • USB host and device
  • Image sensor interface

Qualification and Acceptance testing

Test QT AT
Mechanical Shock
Thermal Cycling
Thermal Vacuum

*QT is performed on the design/qualification model
*AT is performed on the unit to be shipped

Hardware Abstraction Layer Library
This library supports the following peripherals:

  • I2C master mode
  • I2C slave mode
  • Pulse Width Modulation (PWM)
  • UART (RS232, RS422, RS485)
  • SPI master mode
  • FRAM read and write
  • SD card using failsafe FAT journalling filesystem
  • Real-Time Clock (RTC) and OBC internal timer (RTT)
  • Debug LED control

This library offers the following additional functionality:

  • Checksumming (CRC-8, CRC-16, CRC-32)
  • Interface to iOBC Supervisor
  • Watchdog kicking
  • Timekeeping
  • FreeRTOS operating system
  • AT91 library from Atmel

Example Daughter boards:

  • compatible with ISIS bus
  • supported in ISIS Subsystems Library
  • provides interfaces to ISIS solar panels (photodiode and temperature sensors)
  • provides data interfaces (RS-422 and RS-232)
  • provides power interfaces (switchable 3V3 and 5V lines)
  • includes all ISIS Core daughter board functionalities and interfaces
  • includes low-power MEMS gyro
  • includes all ISIS Core daughter board functionalities and interfaces
  • includes 3-axis magnetometer
  • includes 6 PWM and H-bridges to control magnetorquers


  • provides various payload control signals and interfaces while performing simultaneous data acquisition for several payloads


  • provides hot redundant CAN interface and solid state recorder data output to Chang’e-4 relay satellite currently at the Earth-Moon L2 point


  • provides power and data interfaces to the payload and ADCS subsystems
  • iOBC main board
  • JTAG programmer / debugger + USB cable
  • Adapter board (including debugging UART to USB conversion) + USB cable
  • 2 x 2 GB high-reliability SD cards
  • Power break-out board for easy connection to the power supply
  • USB drive containing manuals, iOBC SDK installer, and applicable software libraries
on board computer in the box

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