Iridium SBD + GPS
The BigRedBee SBD + GPS 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 u-blox GPS and power management features provide a completely self contained system, no external components required. Extremely low idle power (< 1ma) consumption means standby times are measured in months.
At just 1.75" x 1.75", the BigRedBee SBD is the smallest complete Iridium SBD system available in the world..
Hardware Details:
| ARM Cortex-M0+ | u-blox MAX-10 GPS module |
| Iridium 9602 SBD Modem | Power Source: (3.3-5.0 volts with 1 amp bursts). Designed to be powered by a single cell lithium poly batter. |
| Size: as small as 1.75” x 1.75” | Bidirectional communication via satellite link |
| Boost Regulator provides 5V at 1A max | Single integrated patch antenna for Iridium and GPS |
| Optional: BMP384 barometric pressure sensor, 900 Mhz LoRa transceiver, SD flash socket and dual i2c ports |
When power is applied, the GPS is enabled to calculate a valid position report. A data packet with latitude, longitude, altitude, timestamp and miscellaneous information is sent to 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 which hours of the day the device is active. These parameters can be controlled remotely
Two versions of the firmware are available. One is targeted at asset tracking of relatively slow moving devices with transmit rates measured in minutes or hours with optional geofencing and transmit schedules. Another is targeted at tracking fast moving devices (high altitude balloons, for example) with transmit rates measure in seconds or minutes with slow and fast data rates that can be triggered via changes in position or altitude)
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-10 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) or an IP address.
- A user provided local server (for example, a Raspberry Pi) receives the data packet and saves it to a local database
- User provided mapping software is used to visualize this data (for example, OpenGTS)
