Remote-Interface-Unit/RIU-datasheet.md

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Tübingen Instruments RIU-9000 Datasheet


Manufacturer: TI (Tübingen Instruments)

Overview

The RIU-9000 is a versatile Remote Interface Unit (RIU) designed for spacecraft sensor management. This device interfaces with an Adafruit BMP280 sensor to provide accurate pressure and temperature readings. The RIU-9000 allows users to configure sensor parameters and retrieve sensor data through a structured 4-step communication protocol.

Features

  • Sensor Support: Integrated support for BMP280 pressure and temperature sensor.
  • Configurable Parameters: Offset and sampling rate adjustments for both pressure and temperature readings.
  • Reliable Communication: 4-step communication protocol to ensure data integrity.
  • Error Handling: Error messages for invalid commands or parameters.
  • Industry Standard Data Format: Sensor data is sent in binary format representing 32 bit IEEE-754 Floating Point values.
  • Lightning Fast Response Time: The RIU-9000 responds to commands after 5 milliseconds.

Commands and Responses

General Format

Commands should be sent as strings over the serial interface at 115200 baud rate. Commands are case-sensitive and must be followed by a newline character (\n). Parameters and values should be separated by a space. Responses from the RIU-9000 will also be in string format.

STARTUP

  • Command: STARTUP
  • Response: READY - Tübingen Instruments RIU-9000
  • Description: Initializes the device. This command must be sent before any other commands are accepted.

GET_SENSOR

  • Command: GET_SENSOR [COMMAND] [SENSOR]
  • Description: Initiates a 4-step communication process to read sensor data.
  • Steps:
    1. REQUEST: Command the device to read sensor value.
      • Command: GET_SENSOR REQUEST [SENSOR]
      • Response: OK or ERROR
    2. CONFIRM: Ask if the device requested the data from the sensor.
      • Command: GET_SENSOR CONFIRM [SENSOR]
      • Response: TRUE or FALSE
    3. CHECK: Ask if the data is present now.
      • Command: GET_SENSOR CHECK [SENSOR]
      • Response: TRUE or FALSE
    4. SEND: Command the device to send the data to the user.
      • Command: GET_SENSOR SEND [SENSOR]
      • Response: [DATA] or FALSE
    5. CANCEL: Cancel the sensor reading request.
      • Command: GET_SENSOR CANCEL [SENSOR]
      • Response: OK

SET_PARAMETER

  • Command: SET_PARAMETER [PARAM] [VALUE]
  • Response: OK or ERROR: UNKNOWN PARAMETER
  • Parameters:
    • PRESSURE_OFFSET: Sets the offset for pressure readings. (In hPa)
    • TEMPERATURE_OFFSET: Sets the offset for temperature readings. (In °C)
    • PRESSURE_SAMPLING: Sets the oversampling rate for the pressure sensor (SAMPLING_NONE, SAMPLING_X1, SAMPLING_X2, SAMPLING_X4, SAMPLING_X8, SAMPLING_X16).
    • TEMPERATURE_SAMPLING: Sets the oversampling rate for the temperature sensor (SAMPLING_NONE, SAMPLING_X1, SAMPLING_X2, SAMPLING_X4, SAMPLING_X8, SAMPLING_X16).

GET_PARAMETER

  • Command: GET_PARAMETER [PARAM]
  • Response: [VALUE] or ERROR: UNKNOWN PARAMETER
  • Parameters:
    • PRESSURE_OFFSET: Retrieves the current pressure offset.
    • TEMPERATURE_OFFSET: Retrieves the current temperature offset.
    • PRESSURE_SAMPLING: Retrieves the current pressure oversampling rate.
    • TEMPERATURE_SAMPLING: Retrieves the current temperature oversampling rate.

RESET_SENSORS

  • Command: RESET_SENSORS
  • Response: OK
  • Description: Resets the request count and communication state.

Communication Errors

  • BUSY: Device is busy. Every 20th request, the device will respond with BUSY and not process the command.
  • ERROR: Generic error message for invalid commands or failed operations.
  • FALSE: Response for confirmation checks that fail.
  • [NO RESPONSE]: After 100 requests, the device will stop responding to commands until a RESET_SENSORS command is issued.

Example Usage

Initialization

User: STARTUP
Device: READY

Setting Parameters

User: SET_PARAMETER PRESSURE_OFFSET 10
Device: OK

User: SET_PARAMETER PRESSURE_SAMPLING SAMPLING_X4
Device: OK

Getting Parameters

User: GET_PARAMETER PRESSURE_OFFSET
Device: 10

User: GET_PARAMETER PRESSURE_SAMPLING
Device: SAMPLING_X4

Reading Sensor Data

User: GET_SENSOR REQUEST PRESSURE
Device: OK

User: GET_SENSOR CONFIRM PRESSURE
Device: OK

User: GET_SENSOR CHECK PRESSURE
Device: FALSE

User: GET_SENSOR CHECK PRESSURE
Device: TRUE

User: GET_SENSOR SEND PRESSURE
Device: [Binary Data]

Resetting Sensors

User: RESET_SENSORS
Device: OK

For more detailed information and troubleshooting, please refer to the official Q&A sessions on friday, 2pm, IRS.