# PC SAT Telemetry Analysis

## PC SAT transmits a total of 32 telemetry values, 16 from each the A and B side. 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 PC SAT, currents from solar panels and from batteries, and voltages from batteries.In order to determine which set of values the packet contains, you must first determine if the values are from the A side or the B side.This is determined by the call sign.For the A side, the call sign (located in the beginning of the telemetry packet) is W3ADO.For the B side, it is PCSAT.Below is a sample of a telemetry packet from the A side.

The “W3ADO” indicates that the telemetry packet comes from the A side.

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.

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.

 Side Cycle Count First Value Second Value Third Value Fourth Value A 00 Current +X Current +Z Current +Y Current –X A 01 Temp  +Y Temp Batt A Temp XMIT A Temp +Z A 10 Temp +X Temp Stack A Current –Y Current Batt A A 11 A-Batt A Volt A- Batt B Volt Power out A 8V Reg A B 00 Current -X Current -Z Current –Y Current +X B 01 Temp -Y Temp Batt B Temp XMIT B Temp -Z B 10 Temp -X Temp Stack B Current +Y Current Batt B B 11 B-Batt A Volt B-Batt B Volt Power out B 8V Reg B

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 B 00 Current -X 0 0.0034 0.2284 -26.6 B 00 Current -Z 0 0.0096 0.864 -53.8 B 00 Current -Y 0 0.0023 0.473 -23.2 B 00 Current +X 0 0.003 0.4 -26.6 B 01 Temp -Y 0 0 0.3414 -19.71 B 01 Temp Batt B 0 0 0.3414 -19.71 B 01 Temp XMIT B 0 0 0.3414 -19.71 B 01 Temp -Z 0 0 0.3414 -19.71 B 10 Temp -X 0 0 0.3414 -19.71 B 10 Temp Stack B 0 0 0.3414 -19.71 B 10 Current +Y 0 0.0038 0.0084 -19.8 B 10 Current Batt B -0.00004 0.0158 -3.32 259 B 11 B-Batt A Volt 0 0 0.09774 0 B 11 B-Batt B Volt 0 0 0.09457 0 B 11 Power out B 0 0 0.0223 0 B 11 8V Reg B 0 0 0.0351 0