Tobias Kaiser
A Computer Engineer's Projects and Ideas

Iridium 9602 USB board

Picture

PCB

PCB

Timeline

I was interested in using the Iridium satellite network for my own communication applications already in the summer of 2015. I was able to buy a used Iridium 9602 Short Burst Data (SBD) modem from Ebay for a small price (much cheaper than a satellite telephone with regular voice / SMS service) and decided to make a PCB for it so I can use it.

I learned the basics about PCB design and started working with the Eagle CAD software package to make a PCB for my Iridium modem. I did not touch the project for a while then, but on July 3, 2016, I finally finished it and ordered it as my first own PCB.

As I was not that experienced with SMD soldering, it also took me some time to assemble the PCB. But apart from the issues mentioned down below under known issues, the PCB did it's job and I was able to send and receive data over the Iridium network.

In September 2016, I wrote a simple gateway program that allows me to send Twitter messages with the Iridium modem.

Description

The purpose of this board was to connect the Iridium 9602 satellite modem to my computer per USB, so that I can easily send and receive data ofter the global satellite network.

Known issues

  1. The antenna used in this design is not supposed to work on the Iridium satellite communication band, but it does.
  2. The Iridium modem needs a large current for transmitting, which is too high for regular USB. The circuit on the PCB is not capable of buffering the current spike of a transmission. A supercap should be included in the next design for this purpose.
  3. The mounting holes for modem were misaligned by a few millimeters, so in order to mount the modem, the holes had to be filed a little bit in order for the screws to fit.

Source

  • The PCB for this project was done with Eagle CAD. Unfortunately I cannot publish the eagle source files of this project.
  • The iridium-twitter GitHub repository contains some useful code to use this PCB to send Twitter messages from anywhere in the world.