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--- iothings:proiecte:2022:razvanandreistoica [2023/01/20 01:28]
razvan.stoica0211
+++ iothings:proiecte:2022:razvanandreistoica [2023/01/20 03:01] (current)
razvan.stoica0211 [2. Hardware]
@@ Line 20: / Line 20: @@
 ===== 2. Hardware =====
 === Mechanical Elements ===
-  * The largest part of the project is the chassis. This allows the movement of an antenna on two axis and also hosts all the electronics.
+  * The largest part of the project is the chassis. This allows the movement of an antenna on two axis and also hosts all the electronics. It uses 4 radial bearings and one axial bearing. Everything (except for the bearings, axes and screws) was 3D printed with PETG.
 {{:iothings:proiecte:2022:fusion_-_copy.png?300|}}
   * The antenna is one of the most important parts of this project. I chose to go with the default antenna that came with the RTL-SDR Kit. It is a V-Dipole adjustable one. In order to make this project work, I had to adapt it and print a piece that keep the two poles at a 120 degree angle. According to an article from the RTL-SDR forum, each pole's size must be 53.4cm.
 {{:iothings:proiecte:2022:adams_v-dipole-500x375.png?300|}}
+  * A dedicated ground plane had to be built for the GPS antenna. It is a 70x70mm PCB with a hole where the cable of the antenna passes.
@@ Line 374: / Line 376: @@
 In order to use the device, one should follow those steps:
   - Connect the Raspberry Pi to the LAN via Wi-Fi or Ethernet (the later might not be possible do to the rotating nature of the device);
-  - Install [[www.airspy.com|SDR#]], [[www.gpredict.oz9aec.net|GPredict]], [[www.wxtoimgrestored.xyz|WXtoIMG]] and [[www.vb-audio.com/Cable|VBAudio Cable (Internal Audio Routing)]];
+  - Install SDR#, GPredict, SDRSharp.GpredictConnector, WXtoIMG and VBAudio Cable (Internal Audio Routing);
-===== 5. References =====
+  - Start SDR#
+  - Select //RTL-SDR TCP// as source -> Click on Gear Icon -> Add the IP address of the RPi (that can be seen in the GUI) in the IP field;
+  - Select Settings (3 lines) -> go to Plugins -> GPredictConnect -> Check the //enable// checkbox;
+  - Select Settings (3 lines) -> go to Audio -> click on Output -> Select //[Windows DirectSound] Cable Input (VB-Audio Cable)//
+  - Select Settings (3 lines) -> go to Radio -> check //WFM// radio button (how funny) and set the Bandwidth to 40KHz
+  - Start GPredict
+  - Go to Edit -> Preferences -> Ground Station and add a new ground station using the information from the GUI (latitude and longitude)
+  - Go to Edit -> Preferences -> Interfaces -> Add new Interface (SDRSharp with default port)
+  - Go to Edit -> Update TLE data from network
+  - Go to Edit -> Update transponder data
+  - Go to File -> New module -> choose a name; choose your ground station name; choose the 3 NOAA satellites (15 18 and 19) and add them to the right -> Click OK
+  - Go to the little triangle to the right (Module options / shortcuts) -> Radio Control -> Select your Radio defined earlier and click Engage
+  - From the Radio Control panel -> Choose a satellite that's in your range -> Choose APT Downlink -> Click Track and T buttons
+  - Go to the little triangle and also check the "Autotrack" checkbox
+  - Open WXtoImg
+  - Go to Options -> Ground Station Location -> Set latitude and longitude -> Click Ok
+  - Go to Options -> Recording Options -> Make sure the soundcard is the VB-Audio Virtual Cable -> Click Ok
+  - Go to File -> Update Keplers (deprecated, must find another way)
+  - Go to File -> Record -> Auto Record
+  - Wait & Hope
+But how does it work?
+  * The SDR#, is, as the name says, a Software Defined Radio. It is used to receive and filter radio waves. This tool uses RTL_TCP as a device (the RTL_SDR connected to the RPi.
+  * GPredict is a software that tracks satellites and predicts their future positions. This tool will adjust the frequency to the desired satellite (closest one when auto-tracking).
+  * WXtoImg takes the analogic data and converts it into images. This software receives the data from SDR# via a virtual "audio cable".
+===== 5. Challenges =====
+Here is a list of past and current problems
+  * Many plastic parts had to be redone multiple times and some still do
+  * The design is really bad
+  * The device needs a power supply
+  * The device needs a way to receive current without cables (maybe brushes or batteries)
+  * The device has 3 antennas near 2 big motors, what could go wrong
+  * RTL-SDR is getting hot, please don't burn
+  * GPS doesn't work indoors (mostly works near windows)
+  * The main antenna is not optimal
+  * The IMU loses its calibration quickly, doesn't have an EPROM and is very hard to calibrate
+  * The IMU doesn't even reach 90 degrees when vertical, for some reason
+===== 6. References and Links =====
   * https://www.noaa.gov/
   * https://www.ngs.noaa.gov/AERO/Genspecs_A/Volume%20A_Attachment%2011-19.pdf
-  * https://www.youtube.com/watch?v=tdGatHMi350
+  * https://www.youtube.com/watch?v=qrcWeYoTGaw
-  * https://www.youtube.com/watch?v=bYpTsersKX8&t=1s
+  * https://www.youtube.com/watch?v=bYpTsersKX8
+  * www.airspy.com
+  * www.gpredict.oz9aec.net
+  * www.wxtoimgrestored.xyz
+  * www.vb-audio.com/Cable
+  * https://usradioguy.com/wxtoimg-kepler-fix/