• RockBLOCK Mk2

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    RockBLOCK can send and receive short messages from anywhere
    on Earth with a view of the sky.

    Compatible with Arduino, Windows, Mac and Linux computers
    (including Raspberry PI™) and many other platforms with serial or USB ports.

About RockBLOCK Mk2

The RockBLOCK Mk2 allows you to send and receive short messages from anywhere on Earth with a clear view of the sky. It works far beyond the reach of WiFi and GSM networks. Maybe you want to transmit weather information from mid-ocean? Or use it to control your robot in the middle of the desert? Perhaps you need to communicate in an emergency, when other networks might not be available? RockBLOCK can help you.

RockBLOCK takes its power from a standard 0.1" pitch direct header connector, or alternatively via an FTDI to USB adaptor (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.

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 a breakout connector over serial, or USB (via a USB/serial adaptor).

Product Details

Powered By Direct Header Connector, or optional FTDI USB adaptor
Built in Antenna Yes (& optional 'SMA' version for external antenna)
Transmits Using Iridium
Weight RockBLOCK Mk2 Naked: 76 grams
Size RockBLOCK Mk2 Naked: 76.0 x 51.5 x 19.0mm
Waterproofing RockBLOCK Mk2 Naked is not waterproof. If you need a waterproof unit, look at the RockBLOCK+
Ideal For RockBLOCK Mk2 Naked: Integration into existing devices

Image Gallery

Running Costs

Line rental is paid in blocks of 1 month, and allows the RockBLOCK to exchange information with the Iridium satellite network. You only pay for months in which you wish to use the RockBLOCK. No annual contract is required. Line rental costs £10.00 per month and includes access to The RockBLOCK management system for managing your devices.

Credits are used each time you transmit. 1 credit is used per 50 bytes (or part thereof) of message sent or received. 1 credit is also used if you check your mailbox and there are no messages waiting (A mailbox check). Credits do not expire, even if you are paying no line rental. Credits are shared/pooled between all of the devices on your account

Bundle per Credit Bundle Price
100 Credits £0.11 £11.00
200 Credits £0.10 £20.00
500 Credits £0.09 £45.00
1000 Credits £0.08 £80.00
2000 Credits £0.07 £140.00
5000 Credits £0.06 £300.00
10000 Credits £0.05 £500.00
20000 Credits £0.04 £800.00

About Iridium

Iridium is the only satellite network that allows transmission of information from any point on Earth – other networks have no coverage in the polar regions, and have intermittent or no coverage in other marine and land areas.

Iridium has 66 satellites in orbit around the Earth, allowing coverage anywhere on Earth 24 hours a day, 7 days a week. No other satellite network has truly global coverage. Messages sent via Iridium take just seconds to reach you, via e-mail or directly to your web-service.

How to 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 - We're working on publishing some samples for other languages soon.

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 our web service are available in the Web Service Guide.

How do I send data to my RockBLOCK?

You can make a simple HTTP POST to our 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’s 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 we do 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 RockBLOCKs, how does billing work?

Our 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 – 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.

Do you guys know what you're doing?

Yes. Rock Seven Mobile Services have been an Iridium Partner since 2008. We've been developing all sorts of products, but most famously we're the people behind YB Tracking.


Related Case Studies

  • Epsom College
    Microtransat Challenge

    Learn about how Epsom College integrated RockBLOCK into their autonomous vessel to compete in the Microtransat Challenge

  • LOHAN
    High Altitude Rocket - The Register

    RockBlock was used as a command and control module, to enable the ground team to send commands to the high altitude rocket when out of GSM coverage

  • Kraken
    Ocean Drifter Buoy

    The pupils at Sutton Grammar School made an ocean drifter to to measure wave parameters and currents. RockBLOCK sends the data back from the middle of the ocean.

  • High Altitude Balloon
    with Arduino and GPS

    Andrew Ashe together with Mikal Hart (author of the fantastic IridiumSBD library for Arduino) has successfully tracked a balloon, and been able to recover its payload thanks to RockBLOCK.