Rocking with the RockBlock (the Iridium modem)

A project log for MyComm

A portable, solar powered, handheld device that provides truly global messaging when you have no alternative.

John Grant 09/21/2016 at 09:060 Comments

At the heart of our prototype MyComm is a RockBlock which handles the Iridium communication. The RockBlock is made by Rock Seven, an Iridium value added reseller. Their aim is to make satellite communications accessible to everybody in a simple and easy to understand way and they manufacture a range of Iridium-based satellite tracking & communication systems and airtime contracts.

The RockBlock is basically a break out board for the Iridium 9602 modem, providing it with an antenna and its power supply requirements. It exposes the modem’s serial interface via a breakout connector over serial, or USB. The Rock Seven management system can be used for managing your devices and configuring API access. There is also an Arduino library - IridiumSBD by Mikal Hart, that has made development quick and relatively painless.

A RockBlock can be purchased from Rock Sevens store and currently costs £159. Line rental is paid in blocks of one month at £8 per month. You only pay for months in which you wish to use the RockBlock and no annual contract is required. Credits are used each time you transmit. One credit is used per 50 bytes (or part thereof) of message sent or received. One 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. Costs for credits depend on what bundle you buy ranging from £6.00 for a 50 credit bundle to £800 for 20000.

We’ve uploaded the RockBlock data sheet and other useful documents to the files list above. All in all we’ve found that working with the RockBlock is really fun and easy. It opens up a whole range of interesting applications and we look forward to seeing what other people do with it!