2. Getting Started

The first thing to do after you open the box is to hook up a battery and charge it if necessary.

2.1. Batteries

For TeleMetrum, TeleMega and EasyMega, the battery can be charged by plugging it into the corresponding socket of the device and then using the USB cable to plug the flight computer into your computer’s USB socket. The on-board circuitry will charge the battery whenever it is plugged in, because the on-off switch does NOT control the charging circuitry. The Lithium Polymer TeleMini and EasyMini battery can be charged by disconnecting it from the board and plugging it into a standalone battery charger such as LipoCharger, and connecting that via a USB cable to a laptop or other USB power source.

You can also choose to use another battery with EasyMini, anything supplying between 4 and 12 volts should work fine (like a standard 9V battery), but if you are planning to fire pyro charges, ground testing is required to verify that the battery supplies enough current to fire your chosen e-matches.

Note

On TeleMetrum v1 boards, when the GPS chip is initially searching for satellites, TeleMetrum will consume more current than it pulls from the USB port, so the battery must be attached in order to get satellite lock. Once GPS is locked, the current consumption goes back down enough to enable charging while running. So it’s a good idea to fully charge the battery as your first item of business so there is no issue getting and maintaining satellite lock. The yellow charge indicator led will go out when the battery is nearly full and the charger goes to trickle charge. It can take several hours to fully recharge a deeply discharged battery.

TeleMetrum v2.0, TeleMega and EasyMega use a higher power battery charger, allowing them to charge the battery while running the board at maximum power. When the battery is charging, or when the board is consuming a lot of power, the red LED will be lit. When the battery is fully charged, the green LED will be lit. When the battery is damaged or missing, both LEDs will be lit, which appears yellow.

2.2. Ground Station Hardware

There are two ground stations available, the TeleDongle USB to RF interface and the TeleBT Bluetooth/USB to RF interface. If you plug either of these in to your Mac or Linux computer it should “just work”, showing up as a serial port device. Windows systems need driver information that is part of the AltOS download to know that the existing USB modem driver will work. We therefore recommend installing our software before plugging in TeleDongle if you are using a Windows computer. If you are using an older version of Linux and are having problems, try moving to a fresher kernel (2.6.33 or newer).

2.3. Linux/Mac/Windows Ground Station Software

Next you should obtain and install the AltOS software. The AltOS distribution includes the AltosUI ground station program, current firmware images for all of the hardware, and a number of standalone utilities that are rarely needed. Pre-built binary packages are available for Linux, Microsoft Windows, Mac OSX. Full source code and build instructions are also available. The latest version may always be downloaded from http://altusmetrum.org/AltOS

2.4. Android Ground Station Software

TeleBT can also connect to an Android device over BlueTooth or USB. The AltosDroid Android application is available from the Google Play system.

You don’t need a data plan to use AltosDroid, but without network access, you’ll want to download offline map data before wandering away from the network.