Date: 5-22-2014
EyeStar S ICD
REV. 1.0
EyeStar Duplex Communications Module
Draft
Near Space Launch Inc.
8702 E. 825 S.
Upland Indiana 46989
TEL: (260) 241-0409
Jeff Dailey
www.nearspacelaunch.com
This document describes the functional, physical, and electrical characteristics of the EyeStar D1 satellite
duplex module. The interface control document is intended to provide the payload intergrator with the
necessary technical information to intergrate with the simplex communication module.
Operational Description
The EyeStar D1 module is designed to send and receive from the user data files to the LEO GlobalStar satellite
network. The downlink data is received by the ground station gateway, forwarded to the Near Space Launch
server and delievered to the end user for processing. Two type of data packets are sent from the module user
payload data and internal DIO / AI data. The DIO / AI data is a set of digital and analog inputs that are sent at a
set intival for health and safety information. There are Four digital and six analog inputs. Two peramitors are
setup by the user transmit inhibit and beacon rate through a setup menu in the module. The payload data is
sent to the module through the serial port, the transmit rate is set by the payload.
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
Digital / Analog Interface Packet
Funtion digital
01
Packet
Count
1 Byte
2 Byte
1 Byte
Analog 1
2 Byte
Analog 2
Analog 3
2 Byte
2 Byte
Analog 4
2 Byte
Analog 5
Analog 6
Status
2 Byte
2 Byte
2 Byte
Tx. Inhibit delay
Power Up
TXD
Downlink
CTS
RF Tx.
RXD
Uplink
Payload Serial Mode
Payload Serial Communacation Packet Format
Payload sends data to the modem when the CTS signal is LOW, once data is sent to the modemit will set the
CTS line HI and send the data to the GlobalStar network. Once complete the CTS line is set back to LOW and
the module waits to receive the next packet from the payload.
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
Payload packet format
Total packet size 512K bytes MAX
Preamble 3 bytes
Payload Data 509K byte
MAX
Fixed pattern ( hex 50 50 50 )
509K bytes Data MAX
Serial Port
A half-duplex (0-5.0V) TTL or LVTTL asynchronous serial port (UART) is the primary interface to payload. The
serial port operates with the seial parameters of 38,400bps, 8 data bits, no parity, 1 stop bit. The Tx, Rx, and
CTS lines are 5V TTL or LVTTL.
RS232 inputs levels are not supported.
Each data packet to the modem is sent in a serial packet. Upon receiving the packet the modem answers with
a ACK if the packet is correct and Transmits the packet, if the packet is incorrect it will send a NAK back to the
payload.
Payload Send Data
Header
Payload
50 50 50
509K Bytes
3 Byte
509K Byte
Modem ACK Response
AA 05 00
Modem NAK Response
AA 05 FF
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
Active Patch Antenna Assembly
Mount inside of satellite (Max. wall 0.0625)
The active patch antenna assembly and coax cables are designed to intergate with the EyeStar Duplex module,
the maximum cable between the module and antenna is six inches.
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
EyeStar Duplex block diagram
Payload Bus Interface
Bus Pin descriptions – I/O
JP4
PayloadTx IN
TX
JP1.1
Payload Rx OUT
RX
JP1.2
Ready to Send
RTS
JP1.3
Clear to Send
CTS
JP1.4
Payload analog input 5
0-5vdc / 10bit
+VIN
JP1.6
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Date: 5-22-2014
EyeStar S ICD
Input voltage 5.5-20vdc
GRD
JP1.7
Regulated + 5VDC output
STATUS
JP1.8
Power ground
DIAG
JP1.9
REV. 1.0
JP1 Mating connector: Micro D Male
J1
Rx Antenna port
ANT
J1
Tx Antenna port
ANT
J2
Physical Characteristics
Dimensions
118.7
61
14
mm
Weight
122
grm
Tempature
-30 to +60
c
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
Mechanical Layout
Absolute Maximum Rating
Parameter
Symbol
Value
Units
Operating Temperature
Ta
-20 to +70
C
Maximum Input Voltage
VIN MAX
5.1
V
Maximum Analog Input Volatage
ADIN MAX
+5.0
V
Specifications
Power
MIN
Input voltage
Input current
4.7
RF Regulator
Tx mode
Idle mode
Typical
MAX
5.0
5.1 V
5.0
V
1
A
5.0
W
100
mA
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Date: 5-22-2014
EyeStar S ICD
REV. 1.0
.5
W
RF characteristics
Operating Frequency TX
1610
1625.5
Mhz
Operating Frequency
RX
2483.5
2500
Mhz
Output power
+31
Modulation
CDMA
dBm EIRP
Communication port
Protocol
Serial N81
Bus voltage
4.8
TTL
5
Data rate
38.4
5.2 V
Kbits
Beacon Mode
Transmit Inhibit
Beacon Time
30
5400 Minute
1
60 Minute
0
5 VDC
Analog inputs
Six
10bit
Source impedance
2.5K
ohm
Digital inputs
Four
TTL
0
5 VDC
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