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Subsystem Build & Test

Table of Contents 1 Team Vision for Subsystem Level Build & Test Phase 2 Radio Technology Development 3 Software Development 3.1 Server/Driver 3.2 Sun Tracking Algorithm 3.3 Callisto Scheduler 3.4 Anemometer 3.5 LabVIEW FITS file reader system 3.6 JSON communication demo 4 CAD 5 Risk and Problem Tracking 6 Plans for next phase 6.1 WEEK10 PLANS 6.2 Brandon (CE) 6.3 Kyle (EE) 6.4 Slav (ME) 6.5 Dave (EE)

Team Vision for Subsystem Level Build & Test Phase

A 4 week plan was implemented for the team to work asymmetrically, playing on each team members strengths

The full list of deliverables and their statuses can be found here

Radio Technology Development

Three possible replacements for the feedhorn antenna have been obtained and measured on a network analyzer.

The original feedhorn was a Terk LOGTVO antenna. This antenna was broken and is in need of replacement. The standing wave ratio (SWR) is the most useful parameter for comparing these antennae.

The three tested antennas are as follows.

Magnavox MG-ANT-104

Boostwaves WA-2608

Boostwaves WA-2802

Based solely on the analyzer measurements, the Boostwaves antennas seem like good fits for replacements. The WA-2802 seems to have a slightly better response.

A test plan is developed to determine gain and beamwidth of the antennas using a transmitter and a dipole. It was attempted using the noise source that is part of the system calibration, but the noise was too low power to be detected by the receive antenna. A proper transmitter will be needed to conduct this experiment.

A full run down of the RF system was attempted, but it was discovered the the RF switch controlling which source the Callisto unit looked at did not work. A replacement is being found.

The TV antenna, ambient dipole, noise source, and 50 ohm load produce expected results when tested separately.

Software Development

Server/Driver

The central SunTracker server/driver integrates the entire system and exposes an HTTP server for management and control. It currently is capable of exchanging messages with the Arduino, communicating with LABVIEW and ASCOM over HTTP/WebSockets, and generating status report and error email notifications.

The ASCOM driver has been adapted to communicate over WebSockets, however hardware testing is pending rewire.

Stack light communication/settings are not yet implemented pending design of the stack light and its protocol.

Controller Protocol

Server Protocol

Demo Server v1.0.1 (Windows x86_64)

Demo Server v1.0.2 (Source)

Screenshot of demo server running interactively. Includes disconnecting and reconnecting Arduino hardware controller.

Sun Tracking Algorithm

This Sun tracking algorithm is to replace the current program for calculating the suns current positon. The current solution does not provide autonomous tracking of the sun. With this algorithm, the positon can be calculated at regular intervals without the need for human intervention. To calculate the position, the python library PyEphem. The library is able to calculate key position data of many bodies in the sky, most importantly the sun. The type of data that can be calculated includes: Right Ascension, Declination, Azimuth and Altitude. This data can be used with the rest of the system to track the sun. Additionally, this library provides the Sunrise and Sunset times for the Calisto Scheduler.

Callisto Scheduler

The Callisto will capture data continuously. The scheduler will use the SunTracking code to calculate the rise and set times and save FIT files for all times during which an observation is scheduled. FIT files not associated with sun tracking or user observation will be discarded.

Anemometer

Arduino code was developed to receive wind data through an ADC. The captured voltages are then converted in to wind speed and transmitted through a serial connection. The integrity of measurements need to be verified, as the equation used to determine wind speed were taken from the data sheet. For now, this is assumed to be close enough for our purposes, as a thorough test of this component is not high priority.

LabVIEW FITS file reader system

Source VI and compiled executable

v2 version has been added, with the following additions:

• Built for 1080p display (v1 was for 2160p)
• Instead of index selection, scales interpret user frequency and time input

http://www.ni.com/download/labview-run-time-engine-2013/4059/en/

LabVIEW 2013 32-bit runtime is required (free download) to run the executable if LabVIEW 2013 32-bit is not already installed. Source VI is available for recompilation. Debugging must be turned on for successful recompilation

VI will work in any 32-bit library, GFITSIO library ONLY works in 32-bit LabVIEW

To open the labview files successfully, the fits library must be installed in user.lib. The FITS library exists in the link below. 32 bit LabVIEW MUST be installed

https://fits.gsfc.nasa.gov/fits_libraries.html#LabVIEW

JSON communication demo

Source VI

To open the labview files successfully, the following libraries must be installed in via VI package manager. The links to the libraries are below.

• VI package Manager
  • https://vipm.jki.net/
• Websockets Library
  • https://forums.ni.com/t5/Example-Program-Drafts/LabVIEW-WebSockets-Library/ta-p/3491490

CAD

/public/CAD/SRT/SRT The following is a summary of CAD work performed

• The previous teams' model was reassembled to accurately reflect dish movement
• The Internals of the PC box were modeled, and a plan to create custom computer hardware mounts was generated for the following
  • SSD holder
  • Custom PCB
  • Motherboard
  • PC Power Supply

Work to be done:

• Custom Dish Mount
• Ionia Observatory Physical Control Panel

Risk and Problem Tracking

ID	Category	Risk Item	Effect	Cause	Likelihood	Severity	Importance	Action to Minimize Risk	Owner
R1	Technical	Improper feedhorn installation	Feedhorn may have loose mounting or be unable to be assembled.	Manufacturing Faults	0	3	0	Feedhorn to be replaced with Antenna	ME
R2	Technical	Unreliable internet connection to Zurich	May not be able to transmit all data overnight.	Environmental conditions including thunderstorms.	2	1	2	"Provide data backup until Zurich server confirms reception"	CE
R3	Technical	Dish may be too heavy for motors/actuators	Tracking functionality is lost, manual repairs required	Ice buildup, power depletion	1	2	2	Motors oversized for current load	ME
R4	Technical	File transfer system error	Zurich server receives incomplete data	Power lost or connectivity issues.	0	2	0	Create Temp file on FTP server, move when complete	CE
R5	Technical	Auto-calibration error	Incorrect data analysis, manual repairs required	Drift of control systems over time	2	3	6	2 callistos in parallel, one for cal one one for data	CE
R6	Technical	Network Communication Error	Remote operation made difficult or impossible	Loss of connectivity, internet outage	1	1	1	Ensure system doesnt rely on TeamViewer/Active user input	CE
R7	Technical	UPS battery dies	System loses power and is no longer operational.	Mains power is lost and UPS battery is exhausted.	1	2	2	Put system into safe shutdown state before battery is exhausted	CE
R8	Technical	RadioEyes/LabView incompatibility	Additional time required for integration solution	No documented API support	0	2	0	Plan B In effect:= custom Astronomical Data	ME
R9	Technical	Feedhorn selection may carry unexpected collaterals (integration)	RX levels may become inefficient for extraction from raw signal	Mismatching impedance and frequency response	1	3	3	Perform extensive testing on feed/dish assembly	EE
R10	Technical	Software Error	Data may be corrupted or incorrect; Zurich may not recieve data at all	Improper program setup / unforeseen program error	1	2	2	"Perform extensive software testing and provide data backup"	CE
R11	Technical	Interference between subsystems	May cause errors or discrepencies in subsystem operation	Improper magnetic shielding on power lines near vulnerable systems	1	2	2	"Isolate magnetic interference, or place wiring more carefully"	EE
R12	Technical	Improper power management	One or more subsystems failing due to internal power loss	Power delivery components insufficient to meet power needs	1	3	3	Perform extensive power system calculations	EE
R13	Technical	Internal subsystem overheating	Damage to one or more subsystems	Inadequate cooling systems or lack of temperature sensor	1	3	3	Test Plan for thermal model validation	ME
R14	Technical	UPS overheat	Damage to battery system	Temperature sensitive battery in harsh enviornment	0	3	0	Will install UPS indoors	ME
R15	Resource	Insufficient budget to meet all project requirements	May need to take performance hits to accomodate cheaper budget	Limited funds (~$500)	0	1	0	$1500 donation from ASRAS	All
R16	Resource	Destruction of Suntracker project hardware	Loss of uniquely designed hardware, project delays	Incorrect assumptions about input levels and tolerances/ general clumsiness	1	3	3	Observe best practices, be careful, stay away from other people	All
R17	Resource	Inadequate space to assemble and test	Team may not be able to build project	Specialized Test Requirements	1	3	3	Ensure that proper space or devices are reserved well in advance, only attempt finaly assy onsite. Prelimnary Assembly at RIT observatory. Wind and Thermal Testing	All
R18	Resource	Theft of system components	Irreplaceable components may be lost	Improper storage of materials	1	3	3	Lock physical project materials in a locker/keep at home	All
R19	Resource	Insufficient backup data storage	Zurich or ASRAS server may fail to recieve data	Insufficient or nonexistant backup data storage	0	2	0	Amount of data needed to exceed data capacity exceeds lifetime of system	CE
R20	"Environmental/Social"	Remote log-in to unit may pose security threat	System may be tampered with by unauthorized user	Malicious actor obtaining password/login information	1	3	3	Use Username/Password +Secure Design	CE
R21	Technical	IP66 may not be as advertized	Water Damage	Leak, improper sealing	1	3	3	Test current enclosure, use waterproof sealing	ME
R22	Technical	Software sends too many emails consecutively	Flooded Mailbox	Periodic Failure alerts	2	2	4	Batch alerts together, rate limit messages	CE
R23	Technical	Smarthost service unavailable	System unable to send email alerts	Service is unavailable	1	2	2	Alternate alert mechanism (stacklight)	EE
R24	Technical	Wind Damage	System components break	High winds, low structural integrity	1	3	3	Reinforce structure	ME
R25	Technical	System resonates with wind	System components break	Winds hitting natural frequencies of structure	1	3	3	Apply Damping	ME
R26	Technical	Heat Sensor Fails	System overheats	Random/Software Failure	1	2	2	Overkill on cooling solution/ Software safeguards	ME
R27	Technical	Humidity Sensor Fails	Loss of humidity information, water damage	Random/Software Failure	1	1	1	Enhanced waterproofing solution/ Software safeguards	ME
R28	Technical	Custom Astronomy Coordinate map unfeasible	Unable to build necessary Radio Eyes Functionality ourselves	Scope too large/Too complicated	2	2	4	Plan C: Track only the sun, deprecate Top40RF requirement	ME
R29	Technical	Improper Antenna Mount	Impossible to get good reading	Focal point miscalculation/ Design Change	1	3	3	Adjustable Antenna mount	ME
R30	Technical	Runaway Dish	Damage to components	Control/Electrical Failure, various	1	3	3	Install E stops	EE
R31	Technical	Shorts and Interference in unit	System Malfunction, Potential Damage	Improper Wiring	1	3	3	Rewiring, Robustification of system	EE
R32	Technical	Software Communication Error	Hardware may not be controlled by PC software	Software doesn't start, starts incorrectly	1	3	3	Arduino defaults into safe position if no PC contact	CE
R33	Technical	Improper Antenna installation	Antenna may have loose mounting or be unable to be assembled.	Manufacturing Faults	1	2	2	Utilize good practices	ME
R34	Technical	Dropped connection	Lack of remote control	To be investigated	3	3	9	Troubleshoot Error, robustify software	ME/CE
R35	Resource	Defective RF switch	RF subsystem does not function	ESD damage?	3	3	9	Purchase new switch	EE

Risk Management Spreadsheet

Plans for next phase

WEEK10 PLANS

Plans listed by individual

Brandon (CE)

• Support Motor Testing work with Slav, Dave
• JSON command integration with Arduino
  • Update controller model based on Arduino feedback
• Implement Callisto scheduler
  • Demo control of Callisto/data collection by server
  • Auto calibration sequence
  • Integrate sun, object tracking with Dave
• FTP upload, data archive
• Arduino robustness
  • Simulate failure/removal of each component, ensure server is notified
  • Error recovery
  • Automatically query environment info etc., update controller model
• Support LABVIEW integration with Slav
• Support stack light integration (tentative)
• Sample web status page (optional)
  • Link status page in email -> help reduce # of emails

Kyle (EE)

• Determine Path forward with Switch
• Low-Noise Amplifiers
  • Determine that LNAs are still functioning
  • Fix janky wiring
• Determine optimal feedhorn
  • Find transmitter to use in gain/beam tests
  • Talk to Jim, he might have a transmitter
• Setup and perform tests with dish
  • Blocked by need for a test setup

Slav (ME)

• Labview communication development
  • Labview GUI design
  • Enviro Displays
  • Error Messages
• Set up Motor for testing with Brandon, Dave
• Case Management - Will Block PC development (nbd)
• Create Mount for Dish -WIP

Dave (EE)

• Finalize rewire
• Enable Motor Testing
• Motor Kill Switch
• Do what Brandon says with PyEphem
  • Create list of Top 40 visible objects as placeholder
  • Function to determine whether object is visible at a given time, and at all times between start/end times (to check (1) whether a scheduled observation is valid / object can be seen and (2) whether observation interferes with sun observation)
  • Function to get all rise/set times between start/end times (e.g. from Monday to Friday, calculate all rise/set times for given object) (to help user schedule an observation)
  • C functions

Plan for week 10 (Integrated System Build and Test)

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