WA8LMF Mirror of WB4APR Website - 21 July 2008 2) Write up a TELEMETRY paper using the formats and stuff you used here to

Starshine Payload Telemetry

 

Starshine will have two or more types of telemetry from various subsystems on board.  The telemetry pertaining to the packet communications system  and communications payload will consist of 16 telemetry values.  These are transmitted in four blocks of five values each (the fifth value is a constant representing the 5 Volt reference).  The different values being transmitted include temperatures on Starshine, nominal primary battery currents, and voltages and Transmitter power out.  This format

Is identical to that used on PCsat so in order to determine values from Starshine, you must first match the callsign of the packet originator.  This is determined by the call sign.  The Callsigns for Starshine will probably be STRSHN.  Below is a sample of a telemetry packet from Starshine: 

 

STRSHN>BEACON:SGATE:T#002,132,138,159,131,213,11111111,0001,0

 

 

                                        The “STRSHN” indicates that the telemetry packet comes from Starshine

 

The next distinction for each packet is the cycle count.  There are four cycles for each side.  Each designated by a 0-3 binary code (00,01,10,11).   These two digits are located on the last two digits of the second to last number separated by commas as shown below. 

 

STRSHN>BEACON:SGATE:T#002,132,138,159,131,213,11111111,0001,0

 

The “01”  indicates that this is telemetry cycle 01.

 

The four values that correspond to the telemetry values are those located directly after the telemetry count (which is represented by T#XXX).  On the telemetry packet above, the four telemetry values are “132,138,159,131.”  The fifth value is a constant, which represents the 5V reference. The table below identifies the location of each value.

 

 

Cycle Count

First Value

Second Value

Third Value

Fourth Value

 

00

Current +X

Current +Z

Current +Y

Current –X

 

01

Temp  +Y

Temp Batt A

Temp XMIT A

Temp +Z

 

10

Temp +X

Temp Stack A

Current –Y

Current Batt A

 

11

A-Batt A Volt

A- Batt B Volt

Power out A

8V Reg A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The following table gives the unit conversion equations for each of the telemetry  values as to the coefficients of a general CUBIC equation of the form Ax^3 + Bx^2 + Cx + D where X is the raw value in the packet.

 

 

Side

Cycle

Channel

 

 

 

 

 

Count

 

A

B

C

D

A

00

Current +X

0

0.0012

0.646

-25.96

A

00

Current +Z

0

0.0048

0.75

-54.6

A

00

Current +Y

0

0.0031

0.241

-25.3

A

00

Current –X

0

0.0024

0.414

-25.3

A

01

Temp  +Y

0

0

0.3414

-19.71

A

01

Temp Batt A

0

0

0.3414

-19.71

A

01

Temp XMIT A

0

0

0.3414

-19.71

A

01

Temp +Z

0

0

0.3414

-19.71

A

10

Temp +X

0

0

0.3414

-19.71

A

10

Temp Stack A

0

0

0.3414

-19.71

A

10

Current -Y

0

0.0037

0.0264

-18.5

A

10

Current Batt A

-0.00004

0.0114

-2.56

252

A

11

A-Batt A Volt

0

0

0.0984

0

A

11

A- Batt B Volt

0

0

0.09826

0

A

11

Power out A

0

0

0.0311

0

A

11

8V Reg A

0

0

0.0356

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WA8LMF Mirror of WB4APR Website - 21 July 2008