Iridium SBD

The BigRedBee SBD allows you to send and receive short messages from anywhere on Earth with a clear view of the sky using the Iridium satellite network.  No cell phone / GSM / APRS or other radio service is required.  The integrated GPS and power management features provide a completely self contained system, no external components required. Extremely low idle power consumption means standby time are measured in months with a battery not much larger than the transmitter itself.

At just 1.75" x 1.75", the BigRedBee SBD is the smallest complete Iridium SBD system available in the world..

Hardware Details:

 

 MK20DX256 32-bit Cortex-M4 CPU    56 channel u-blox MAX-7 GPS module
Iridium 9602 SBD Modem                                    Powered by single cell lipo battery  (4.2 volts)
Size:  1.75” x 1.75”   Custom designs available at a nominal charge  
Boost Regulator provides 5V at 1A max
Remote control of transmitter schedules    

 

                          

When power is applied, the GPS is enabled to calculate a valid position report.  A data packet with latitude, longitude, altitude, timestamp and some other miscellaneous information is constructed and sent to its destination via the Iridium satellite network.  The ASCII packet can be converted to binary to reduce the packet size.  The entire device then enters a low power sleep state for a user specified time period before waking and repeating this process.  Other parameters can control which  hours of the day the device is active. These parameters can be controlled remotely.

The device must be activated with an Iridium data service provider.  Data plans start at $16/month for 12Kbytes of data (yes, 12000 bytes).   This device is intended for low bandwidth applications.  Sending just one position report every hour continuously for an entire month would require approximately 18,000 bytes.

 

        

 

Unlike other Iridium transceiver modules, the 9602 uses a single antenna for both Iridium and GPS satellite communications.             

                                   

Data Flow:

  •  The u-blox MAX-7 GPS chipset on the BRB SBD obtains a position report from the GPS satellite constellation 
  • A data packet is constructed and transmitted to the Iridium satellite network using the Iridium 9602 modem
  • Any available incoming messages are downloaded and processed
  • The Iridium satellite network sends the data packet to a centralized ground station 
  • The ground station forwards the data packet to your email inbox (for example, a dedicated gmail account) 
  • A user provided local server (for example, a Raspberry Pi) extracts the data packet from email and saves it to a local database 
  • User provided mapping software is used to visualize this data (for example, OpenGTS)