EyasSat FAQ (EyasSat)

What is EyasSat?

posted Mar 30, 2009 6:55 PM by Tim White

EyasSat is the name of a working satellite model for classroom use.

It was originally developed for use in the Astronautics Department at the U.S. Air Force Academy.

The mascot of the USAFA is the falcon and satellites built at the USAFA are called Falconsats.

An "eyas" is a baby falcon.

Are discounts available?

posted Mar 30, 2009 6:54 PM by Tim White

CSS would be glad to discuss volume discounts for orders of more than 10 EyasSats.

Since we primarily sell to educational institutions, our pricing is already the educational pricing.

How can I make an experiment board for an EyasSat?

posted Mar 30, 2009 6:52 PM by Tim White

The best way is to make a board in the PC-104 physical format that meets the EyaBus specification.

The required connections are the SPI pins, one of the CS lines dedicated to experiments, and power.

Any microcontroller that talks SPI could be used, Atmel and PIC are the likely candidates. A single purpose IC that talks SPI might also be used.

The document "How to design an experiment" in the Downloads section contains all the details you need to build an experiment board that plugs into the EyasSat stack.

We strongly recommend one of the switched power pins be used to run the board. 5V and 3.3V are available.

There are also discrete I/O pins from the IHU available to interface to experiment boards. See the hardware manual and the EyaBUS pin diagram for further detail.

Addtionally it is possible to unplug the torque rods and plug in other devices that operate from a PWM 9VDC source.

How can I get an EyasSat?

posted Mar 30, 2009 6:51 PM by Tim White

CSS builds to order only and runs two or three production cycles each year. Please see the home page for the datas of the current production cycle. We accept POs via FAX. Please Contact Us to order your EyasSats.

What does an EyasSat system cost?

posted Mar 30, 2009 6:50 PM by Tim White

The EyasSat complete core system is priced at $7,995.

This includes a User's Manual that contains a complete set of lab exercises and Owner's Manual with hardware details and lab setup information.

We are pleased to also be able to include a CD containing all the curriculum material from the AFA Astro 331 course including lectures and instructor information (exams and some copyrighted material is deleted).

All you need to get started using the EysSat in your learning environment is a bench with a couple of power supplies and a PC or laptop.

What computers or mircoprocessors are used in the EyasSat?

posted Mar 30, 2009 6:49 PM by Tim White

The C&DH board uses an Atmel MEGA128. In Rev A EyasSat the other modules used the Atmel AT90S8535 (or Mega8535).

The current model (Rev C) uses ATMega128s throughout.

Using these is one way the power consumption has been kept low enough to run on batteries for an hour or so in the lab. These processors are very well supported by CodeVision.

What language is EyasSat programmed in?

posted Mar 30, 2009 6:48 PM by Tim White [ updated Mar 30, 2009 6:49 PM ]

All code/firmware for EyasSat was done in C using the excellent CodeVision C development environment for the Atmel AVR RISC microcontrollers. See http://www.hpinfotech.ro .

My EyasSat telemetry is displaying all "8"s (or all of some other character/garbage). Help!

posted Mar 30, 2009 6:47 PM by Tim White

Chances are, your batteries are depleted. Pull the power enable plug. or flip the "off" switch, then put your stack on the charger. Things should be back to normal in no time.

Can the modules operate without the IHU?

posted Mar 30, 2009 6:47 PM by Tim White

Yes. The EyasSat uses a distributed processing design. The EPS and ADCS modules include processors and a direct serial interface that may be connected directly to a PC. Those boards may be operated stand-alone or in the stack.

How do the EyasSat modules communicate?

posted Mar 30, 2009 6:46 PM by Tim White

The primary means of communications between the microprocessor in the C&DH modules and the other modules is an SPI bus.

The C&DH acts as the bus master, the modules are slaves. Chip select lines are assigned to each module.

Chip select lines are also reserved for up to three experiment boards that may be designed/built/used by owners and added to the EyasSat stack.

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EyasSat FAQ