In the city, which is home to the master, there is a large metal construction that rotates and indicates the position of the planets in the sky. The device that made the wizard also indicates the position of the planets in the sky and their coordinates.
Let’s see a small video.
For the manufacture of such a device the master used the following
Tools and materials:
– Raspberry Pi (version 3 or higher)
– LCD screen (16 x 2);
– Stepper motors with drivers (28-BYJ48) – 2 PCs;
– Buttons – 3 PCs;
– Flange coupling – 2 PCs;
– Nuts and bolts M3 – 8 PCs;
– 3D printed parts;
Step one: location, access, code
Homemade decorated a little differently, as you can tell from the end. But, in order not to get confused, won’t change the order set by the master.
There are several ways to determine the location of astronomical objects in the sky.
In this case the most appropriate is the horizontal coordinate system.
The horizontal coordinate system gives in this case the angle from North (azimuth) and up from the horizon (altitude). Then the pointer of planets must determine the North coordinates of the location.
Instead of trying to calculate the altitude and azimuth, which vary with time and location, the master will receive data from NASA. Data transmission on the Raspberry Pi will be through Wi-Fi connection.
Data master will obtain from the jet propulsion Laboratory of NASA (JPL) – https://ssd.jpl.nasa.gov/?horizons
To access this data it uses a library called AstroQuery, which is a set of tools for querying astronomical web forms and databases. The data for this library is here: https: //astroquery.readthedocs.io/en/latest/jplhor ...
On Raspberry installed Raspbian and installed python 3 programming.
The program enters the following command:
sudo apt install python3-pip
Then you need to use pip (a package management system) to install the updated version astroquery:
pip3 install --pre --upgrade astroquery
Before continuing with the rest of this project, the wizard validates the installation using a simple Python script showing the direction of Mars:
from astroquery.jplhorizons import Horizons mars = Horizons(id=499", " location='000', epochs=None, id_type='majorbody') eph = mars.ephemerides() print(eph)
The accuracy of the data can be checked by using the site to search for positions the planets https://theskylive.com/planetarium
id is the number that identifies the Mars JPL, epochs is the time of receipt of the data, and id_type indicates the main body of the Solar system. “000” is the code for the location of the Observatory in Greenwich UK. Codes for other sites can be found here:https://minorplanetcenter.net//iau/lists/ObsCodesF....
If the command POPs up a error (No module named ‘keyring.util.escape) , then you need to type the following command:
pip3 install --upgrade keyrings.alt
Wizard has provided a code that can be downloaded below. To find the right data for your location, you need to go to parts of the code getPlanetInfo and change the location to the right.
def getPlanetInfo(planet): obj = Horizons(id=planet", " location='000', epochs=None, id_type='majorbody') eph = obj.ephemerides() return the eph
Step two: installation
On the breadboard the wizard installs Rasbury, stepper motors, screen and three buttons, as shown in the diagram.
In order to know the Pinout of Rassberry need to enter the command: pinout
The contacts that connects the master with the following:
1st stepper motor – 7, 11, 13, 15
2nd stepper motor – 40, 38, 36, 32
Button 1 – 33
Button 2 – 37
Button 3 – 35
LCD screen – 26, 24, 22, 18, 16, 12
After connecting the script: python3 planetFinder.py On the screen to begin the download, and buttons, you can control stepper motors.
Step three: design
The housing and the pointer in the form of telescope was designed for 3D printing. The hole sizes correspond to the sizes of nuts and bolts M3.
Files for printing can be downloaded below.
Step four: assembling
After printing the parts you need to check the details are matched and sanded them.
Then proceeds to the Assembly of the device.
Stepper motor that will control the tilting angle of the telescope will be located above the main body and rotate so that the wire need not be taut.
The master holds the wires and primaeval to the Board. Then check the engine and if everything is OK fixes it.
Installs on the front panel screen and buttons. Primaeval wire.
The second stepper motor is mounted in the housing and on the shaft is fixed to the flange. The second flange is attached to the telescope pointing.
Sticks a small compass to the body.
Step five: use the device
Not to run the code manually each time you want to find a planet the wizard installs the autorun.
In the terminal you need to enter enter
In the opened file at the end, add the following command:
@reboot python3 /home/pi/PlanetFinder/planetFinder.py &
/home/pi/PlanetFinder/planetFinder.py is the location of the file. If the code is stored elsewhere, then the line you want to change.
The & symbol at the end is important, as it allows code to run in the background.
After switching on the device need to adjust it vertically. By pressing the buttons “up” and “down” to set the horizontal position and confirm the selection with the bottom button.
Then, you set the North direction and confirm the selection.
It is now possible to sort planets by using the buttons up / down and selecting one of them, confirm the selection with the button ok. The screen will display the altitude and azimuth of the planet, and the telescope will turn in her direction.