DINO CDR CDH 09 September 2021 Command Data

DINO CDR – C&DH 09 September 2021 Command Data Handling Winkelman, Martin Jayaraman, Vijay Bhatia, Vishal

DINO CDR – C&DH 09 September 2021 Introduction • Command Data Handling subsystem is responsible for computing and control of subsystem functions. • The core of this subsystem is a single-board computer powered by the Intel PXA 255 Processor with the PC/104 form factor. Colorado Space Grant Consortium 2

DINO CDR – C&DH 09 September 2021 System Functional Diagram FLIGHT COMPUTER USB SERIAL PORTS +5 v PC/104 ADCS POWER SCIENCE TIP-MASS RS 232 Serial 802. 11 b General Purpose I/O Pins MECHANISMS CPLD Serial to 802. 11 b bridge I/O Board TNC RADIO COMM THERMAL INTERFACE E Colorado Space Grant Consortium THERMAL 3

DINO CDR – C&DH 09 September 2021 Design Changes Since PDR • Externally triggered reset is no longer design requirement • External watchdog provided by power system • We will try to avoid multiplexing inputs if possible • Additional 32 MB flash memory needed • Interface requirements have changed for some systems – Serial link to 802. 11 b bridge now used for tip mass in place of using 802. 11 b card on computer – Science will also be using a serial port – Some systems have added analog and/or digital interface lines Colorado Space Grant Consortium 4

DINO CDR – C&DH 09 September 2021 Functional Requirements – – – – C&DH must not exceed 7 Watts. Maximum ½ kg. External watchdog timer. 3. 8” x 3. 6” x 4” profile Must run Linux 32 MB RAM minimum 16 MB FLASH + additional 32 MB FLASH Colorado Space Grant Consortium 5

DINO CDR – C&DH 09 September 2021 Interface Requirements System Digital Out --------ADCS 3 Comm 0 Power 1 Mech 0 Science 1 Thermal 0 Tip Mass 0 --------TOTALS 5 Digital In -----0 0 0 2 1 0 0 -----3 Analog Out -----3 0 0 0 -----3 Analog In ----9 0 0 17 0 30 0 ----56 Colorado Space Grant Consortium Other I/O ----2 x serial + 2 x USB serial ----5 serial, 2 USB 6

DINO CDR – C&DH 09 September 2021 Design Compliance • All digital I/O, serial, and USB ports are built in to Viper • Additional flash memory will be installed in the Compact. Flash socket • Analog I/O will be provided by additional COTS board using PC/104 bus Colorado Space Grant Consortium 7

DINO CDR – C&DH 09 September 2021 Safety Requirements • • • System is contained within a closed box System ground will be isolated from structure ground System is not active without power There are no high current inputs or outputs There are no moving parts Colorado Space Grant Consortium 8

DINO CDR – C&DH 09 September 2021 Arcom Viper • • PXA 255 400 Mhz CPU SDRAM: 64 M FLASH: 16 M 256 K Battery Backed SRAM Real-Time Clock Watchdog Timer Interfaces: – – – – 2 USB v 1. 1 5 Serial Ports Compact Flash Drive Support Ethernet: 10/100 Base. T JTAG 8 Digital In / 8 Digital Out PC/104 Colorado Space Grant Consortium 9

DINO CDR – C&DH 09 September 2021 Specifications – Viper Overview Power Requirements: • 1. 6 W @ + 5 V only supply (typical) • 200 m. W @ +5 V (standby mode) Operating Temperature: • -20°C to +70°C Weight: • 96 Grams Form Factor: PC/104 Colorado Space Grant Consortium 10

DINO CDR – C&DH 09 September 2021 PC/104 Module Form Factor Colorado Space Grant Consortium 11

DINO CDR – C&DH 09 September 2021 Design Details • Current design anticipates using 3 industry standard PC/104 size boards. • Analog Inputs/Outputs will be provided by a PC/104 expansion board. • Custom circuitry, if necessary, will be simple, such as a multiplexor or thermistor driver. Colorado Space Grant Consortium 12

DINO CDR – C&DH 09 September 2021 Analysis and Prototyping • Some software testing has already been done on Computer • No prototyping necessary for COTS components as long as interface specifications are followed Colorado Space Grant Consortium 13

DINO CDR – C&DH 09 September 2021 COTS Parts Status Part Availability Status Arcom Viper Lead time of less than 2 weeks 1 has been procured I/O boards TBD Different options are still being evaluated Colorado Space Grant Consortium 14

DINO CDR – C&DH 09 September 2021 I/O Board Make or Buy Rationale • Make – Better selection of interface options – High reliability components can be selected • Buy – Can fit more interfaces on a board – Software implementation is much simpler – Not much more expensive than fabricating custom board Conclusion: We will buy the I/O board Colorado Space Grant Consortium 15

DINO CDR – C&DH 09 September 2021 Manufacturing and Testing Constraints • Manufacturing – Boards connected using PC/104 mountings – Wiring will be soldered to connectors • Testing – Most testing will be done with software simulation and readily available test equipment – JTAG can be used to troubleshoot system hangs Colorado Space Grant Consortium 16

DINO CDR – C&DH 09 September 2021 Ground Support Equipment Requirements • Power system must be integrated before C&DH integration – A standard 5 volt power supply can be used when testing system before power is integrated • Ethernet Port on Viper will be used for testing during integration – The serial port can also be used for testing until the Comunications system is integrated Colorado Space Grant Consortium 17

DINO CDR – C&DH 09 September 2021 Documentation • Design Review – Preliminary Design Review – Peer Review • Test Plan – Outline for C&DH system • Trade Studies – Arcom Viper vs. other PC/104 computers • To read over any of the following topics please go to http: //spacegrant. colorado. edu/dino/CDH. htm Colorado Space Grant Consortium 18

DINO CDR – C&DH 09 September 2021 C&DH Schedule • Interface Board – March 15 -19 Select and procure I/O board – April 5 -9 Testing • Custom Hardware – March 22 -26 Determine if custom board is needed – March 29 – April 2 Design and testing – April 12 -16 Testing • End of Semester Review – April 19 - 23 Integrate all boards together – April 25 – May 10 Testing Colorado Space Grant Consortium 19

DINO CDR – C&DH 09 September 2021 Issues and Concerns • Unknown effects of radiation on COTS parts • Final choice for I/O board has not been made Colorado Space Grant Consortium 20