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1
Challenges in work / Re: Long Range Communications
« Last post by Cosmoneer on May 29, 2017, 05:50:24 PM »
Using the programming cable and the serial IrDa board (and/or the teacher remote module), the Cosmoneer is put into Command & Control Mode.


This mode will perform the following:

Once the command mode signal is received, the Cosmoneer will find magnetic north via the onboard compass, then proceed to slowly hunt for a serial IrDa homing signal.  Once this signal is found, the cosmoneer will record the starting compass heading for reception of this signal and will continue listening for the signal until the signal is lost, at which point the cosmoneer will record the end angle.  Once the signal is lost for a period of time and additional compass angle has passed, the cosmoneer will compute the mid-point of the homing signal and will return to that point and broadcast an "acknowledged" signal, to which the transmitter of the command signal will send an "ok" signal, to which the Cosmoneer will then send a "ready" signal.

At this point the Cosmoneer is waiting for a simple compass heading command, and upon receiving it will maneuver to that heading and wait there for one minute.  If it receives any data during this time, at the end of one minute, it will maneuver to face the command signal source and will relay the data it received.  If no data was received, then the cosmoneer will simply broadcast a "done" signal, followed by a "ready" signal.
2
Remote Telemetry & Control Module / Re: Telemote Unit
« Last post by Cosmoneer on May 15, 2017, 01:15:05 PM »
Developing the transmission packets, we'll explore what is possible using these instructables:

https://www.instructables.com/id/RF-315MHz433MHz-Wireless-and-Arduinoagain/
https://www.instructables.com/id/RF-315433-MHz-Transmitter-receiver-Module-and-Ardu/

As well as using the Arduino "RadioHead" library, found here:
http://www.airspayce.com/mikem/arduino/RadioHead/
(Video of the library in use:  https://www.youtube.com/watch?v=LJ_1R9PcQfM)
3
Remote Telemetry & Control Module / Re: Telemote Unit
« Last post by Cosmoneer on May 15, 2017, 12:58:59 PM »
Borrowing from NASA's GOES satellite telemetry section, we arrive at the following list of telemetry items we should transmit from the Cosmoneer:



  • General Parameters: Craft ID, Commands: Last Five/Next Five, Command Counter, Safe Mode Status
  • Cosmoneer Configuration Status (Onboard systems and their health/availability)
  • Environmental sensor data (temp, light, pressure, etc.)
  • Power parameters and voltages of modules, current consumption, battery temps, etc
  • Attitude determination and control parameters (compass cal. values, heading, angular rates, etc.)



[NASA's GOES satellite telemetry section.
https://goes.gsfc.nasa.gov/text/databook/section09.pdf

Another source of telemetry guidance is found here:
https://ocw.mit.edu/courses/aeronautics-and-astronautics/16-851-satellite-engineering-fall-2003/lecture-notes/l20_satellitettc.pdf
4
Remote Telemetry & Control Module / Telemote Unit
« Last post by Cosmoneer on May 15, 2017, 12:28:05 PM »
The Remote Control & telemetry module, as we have envisioned it thus far, will contain the following:

  • Dual Axis X-Y Joystick module (one potentiometer per axis)
  • Tactile Button (Momentary On)
  • DS1307 I2C clock, CR1220 battery & Holder and 128K I2C EEprom memory module
  • Atmega 328P-AU (Arduino Pro Mini) board
  • 5v Lithium battery charger/boost board
  • Lithium 18650 3.7v battery & holder
  • OLED 0.96" I2C Display
  • Serial IrDa board
  • 433Mhz wireless receiver board

The 433Mhz radio will receive telemetry information from a Cosmoneer equipped with a 433Mhz radio transmitter.  Telemetry information will appear on the OLED display.

The user can control the Cosmoneer via the joystick and button.  Control information will appear on the OLED display, prior to being transmitted via Serial IrDa.  Real-time control may be achievable only during direct (line-of-sight) communications, since directly controlling the CMG will most likely result in a rapid loss of control, unless limits are placed on the turn speed (angular turn rate) the CMG is allowed to impart to the Cosmoneer.

The user may also navigate through control/demo options available from the Cosmoneer via the joystick and button.  The Telemote unit will poll the Cosmoneer for options before presenting them to the user.

Menu navigation will be manage by using this library:
https://code.google.com/archive/p/m2tklib/
5
Power Systems / Solar Energy Harvesting
« Last post by Cosmoneer on May 15, 2017, 11:05:47 AM »
Successfully scaling down a real spacecraft power system to a usable size, especially in an indoor environment is a difficult obstacle to overcome.  Through testing and evaluation of example circuits and various solar cell options, as well as reviewing other users discoveries has left us with a renewed interest in incorporating solar energy harvesting as a viable option for the Cosmoneer.

Back in 2013 when the Cosmoneer idea was beginning to take shape, Solar energy as a power source was the focus for nearly 6 months.  Four years later, we believe we can incorporate ideas presented by others on the internet as a means to successfully power the Cosmoneer (albeit intermittently.)

In this video, Shahriar shares his demonstration of the LTC3105 energy harvesting chip and suggests using two of them in series with a super capacitor in-between.  What he demonstrates is the second circuit harvesting as much usable power as possible from the super capacitor.

https://youtu.be/lrELRVFEx_s
(from Shahriar's blog post, here:  http://thesignalpath.com/blogs/2013/01/03/tutorial-and-experiments-on-energy-harvesting-ics/)


As with all things Cosmoneer, the idea is to constrain the Cosmoneer to problems faced by typical spacecraft, only on a smaller scale.



6
Command & Data Handling (microController) / Re: Command and Control
« Last post by Cosmoneer on May 10, 2017, 03:51:28 AM »
Hi Robert,

Did you have any luck getting this installed?  Also, what was the specific error message you received during the installation?



-Cosmoneer
7
Structures & Mechanical / Incorporating Injection Molding
« Last post by Cosmoneer on April 27, 2017, 03:24:02 PM »
Hi all!

Now that we have obtained a small scale injection machine, we wanted to list some of the areas of improvement or areas we wanted to reduce complexity/cost while adding to the integrity of the Cosmoneer.

Targeted Areas of Improvement
  • Front PCB attachment points/methods
  • Receiver Coil & support
  • Rear PCB attachment points
  • Counterweight attachment point

Easy Injection Convertible Parts
  • Support Feet
  • Front Legs
  • Thread Spool
  • Coil Cover

Large Injector needed
  • Upper & Lower Support Arms
  • Main Stand Support Plate
  • Dash/Gyro Support
  • Inner Hanger


Any ideas or suggestions you have on these items?  Leave a post!
8
Command & Data Handling (microController) / Re: Command and Control
« Last post by digital_gods on April 23, 2017, 11:41:34 PM »
I found a breif tutorial for configuring COSMOS and Arduino to play together. http://www.williamosman.com/2016/08/cosmos-and-arduino-20-telemetry-system.html?m=1
I'm trying to get Ball Aerospace Cosmos (http://cosmosrb.com) telemetry software to work on Win10 64-bit without much luck. A couple of the components don't get installed not will the demo load. This week I'm setting up a Win 7 VM to test on. Can someone else see if it will install on their copy of Win 10?

--Robert
9
I visited NASA's new SSBK website and read section #5 on GNC.  Interestingly, Control Moment Gyros were not mentioned anywhere in that section.  Since CMGs are not good at high accuracy pointing (yet), I can only speculate that they were omitted since they are typically not chosen for space missions where accurate pointing is required.

https://sst-soa.arc.nasa.gov/05-guidance-navigation-and-control

This knowledgebase will be in constant flux, so I expect this to change in the future.
10
Communications (Serial IrDa) / When you really want to do RF
« Last post by Cosmoneer on April 12, 2017, 04:05:33 PM »
So, you want to do RF instead of Infrared?  You could try a microstrip YAGI antenna and have directional WiFi. 

http://file.scirp.org/Html/4-6801183_29799.htm

http://www.qsl.net/va3iul/Antenna/Printed_and_Microstrip_Antennas/Design_Ideas_for_Printed_and_Microstrip_Antennas.htm
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