You can send and receive short messages from anywhere on Earth with a clear view of the sky using the RockBLOCK Satellite Communication Device. It operates in areas where WiFi and GSM networks aren't available. Maybe you wish to send weather data from the middle of the ocean? Or use it to command your robot in the middle of nowhere? Maybe you need to communicate in an emergency and other networks are unavailable? You can use the Mk2 to your advantage.
At the heart of Mk2 is an Iridium 9602 modem. The Mk2 hosts the 9602 and provides it with an antenna, and its power supply requirements. It exposes the modem’s serial interface via a breakout connector over serial, or USB (via a USB/serial adaptor).
It takes it’s power from a standard 0.1″ pitch direct header connector, or alternatively via an FTDI to USB adapter (to power/control from a USB port). If you’re using the PCB assembly version with a direct header, your host needs to supply a minimum of 100mA @ 5V.If you’re interested in a smaller version of the unit, then the 9603 version of the product might suit you better – designed primarily for product developers and system integrators where space inside an enclosure is at a premium.
Direct Header Connector, or optional FTDI USB adaptor
Yes (& optional ‘SMA’ version for external antenna)
How do I control the sleep pin? The sleep signal is internally pulled high on the RockBLOCK and RockBLOCK+ products, so you can leave it disconnected if you want to leave the modem 'awake' all of the time.
To turn 'off' the modem, pull the line to ground.
Unit refuses to give me data using the SBDRT command? If you are using the SBDRT command, and the modem appears to 'hang' when you issue the command, it is probably due to flow control configuration. The default state for the RockBLOCK and RockBLOCK+ units has flow control turned ON in the modem. When running in 3-wire serial mode, flow control should be turned OFF, which will ensure you get responses to your requests. Use the command AT&K0 at the start of your command sequence. This turns flow control off, and should solve the problem.
How does it work? RockBLOCK uses the Iridium Satellite network. Specifically, it uses an Iridium service called ‘Short Burst Data’ (SBD). There’s some official info here. At the heart of RockBLOCK is an Iridium 9602 modem. The RockBLOCK hosts the 9602 and provides it with an antenna, and its power supply requirements. It exposes the modem’s serial interface via USB (or directly – PCB assembly version only). Full documentation for the 9602 modem can be found here: Iridium 9602 SBD Transceiver Product Developers Guide.
How is it powered? RockBLOCK takes its power from the direct header connector, or alternatively via the optional FTDI/USB adaptor. If you’re using the PCB assembly version with a direct header, your host needs to supply a minimum of 100mA @ 5V.
How much data can I send/receive 340 bytes FROM RockBLOCK. 270 bytes TO RockBLOCK.
How quickly can I send a message? Testing shows that it generally takes around 20 seconds from power-up to successful transmission, with a perfect view of the sky. With a very restricted view, it may take several minutes.
How frequently can I send a message? You should be able to complete an Iridium SBD session roughly every 10 seconds, assuming a perfect view of the sky.
Can I connect an external antenna? Yes, there is a version of the RockBLOCK available with an SMA connector (instead of the built-on antenna) which allows you to attach an external Iridium antenna.
Do you have USB drivers for my XYZ platform? Almost certainly. If you have purchased the optional FTDI-USB adaptor then you will need to install the FTDI drivers. You can check on their website (http://www.ftdichip.com/FTDrivers.htm), where you will find drivers for Linux, Mac, Windows, Android and others.
What about software? The RockBLOCK appears as a serial interface, and you can talk to it using a simple set of AT commands. It is expected that you'll be able to integrate it into your own software with minimal effort.
Could you give us some sample code to get started? There is a Node.js library available and an Arduino library which you can get via the RockBLOCK page - There is also an excellent Python project for Raspberry Pi, which would make a great starting point for any Raspberry Pi users which can be found here - Rock Seven is working on publishing some samples for other languages as well.
How do my messages get back to me (on Earth)?
Messages sent from RockBLOCK can either be delivered to your chosen email address, or sent to your own web service as a simple HTTP POST. The message data will be hex encoded so there are no character set problems. Full details of RockBlock's web service are available in their Web Service Guide available for download here.
How do I send data to my RockBLOCK? You can make a simple HTTP POST to RockBLOCK's web service. The message is queued on the satellite network almost instantly, ready for RockBLOCK to download (on your command).
Does RockBLOCK get notification of a new message waiting? Yes, as long as you configure it correctly. Check the 9602 documentation for the 'Ring Alert' feature.
How Rugged/Waterproof is it really? Very! The RockBLOCK+ is a completely encapsulated design, so it is at least IP68 (submersible for extended periods). Just don't expect it to send messages from under water!
Do I get positions with my messages? The RockBLOCK does not have a GPS chip inside it. It‚Äôs invisaged that if you want position reports, you would use an off-the-shelf GPS module with your solution, and get position data from that. However, it is worth noting that with each Iridium transmission we do get an approximate position report - this varies in accuracy from 100km to 1km, and therefore cannot be relied upon for very accurate tracking, but RockBLOCK does provide this information for you (along with the approximate accuracy, 'CEP' in km) with your messages. If you are looking for a dedicated tracking satellite tracking device, then you might want to consider our RockSTAR product.
If I have a whole set of RockBLOCK's, how does billing work? Billing is flexible, and allows you to pay only when you are using your devices. Line rental is sold in one-month blocks, and credits are bought in packs. If you have several RockBLOCKs, credits are shared from a credit pool amongst all your devices and you don't need to buy separate packs of credits for each device. Similarly, if only some of your devices are being used at any one time, you don't need to pay for line-rental on those which aren't in use.