SkySafari is a great astronomy app for smart devices like the iPhone, iPad and Android.
The SkySafari Plus and Pro versions add the possibility to remote control your GoTo telescope mount using the special SkyFi adapter.
This adapter sends serial (RS-232) commands, received with a wireless connection, to the handset of the GoTo mount.
Using SkySafari in combination with SkyFi increases the number of objects you can observe and current events in the sky (like comet PANSTARRS at the moment) are found easily this way.
I was wondering if it would be possible to create something like SkyFi using the Raspberry Pi.And yes, it is possible. Quite easy actually!
Step 1: What Do You Need?
- Raspberry Pi configured with a working network connection (WiFi preferred, of course).
- USB to Serial cable.
- GoTo telescope mount
- PC Serial to GoTo handset cable (shipped with your GoTo mount).
- SkySafari Plus or Pro
- Basic Linux knowledge
Step 2: Configuring the Raspberry Pi
Now how are we to receive the commands from SkySafari?
This is done by the Serial To Network Proxy (ser2net).
sudo apt-get install ser2net
Add the following line, using your favorite text editor, at the end of the ser2net configuration file (/etc/ser2net.conf) which contains the port where ser2net is listening on:
4000:raw:0:/dev/ttyUSB0:9600 NONE 1STOPBIT 8DATABITS
In this case, I chose port 4000. You may choose another port but be sure it is between 1024 and 65535 and does not conflict with any other daemons listening on the same port.
Restart the ser2net service with the new configuration:
sudo /etc/init.d/ser2net restart
Step 3: Configure SkySafari
Next, configure your telescope in SkySafari.
My setup has a SkyWatcher SynScan GoTo on a EQ3-2 equatorial mount.
Be sure to enter your setup and don’t copy my settings bluntly ;-)
The IP address in the picture above corresponds with my Raspberry Pi.
Of course, you should enter the IP address of your Raspberry Pi.
Same goes for the listening port. I’m using port 4000.
If you configured a different one for ser2net, enter that one.
After that is done, you should try to connect SkySafari with your mount in the Scope menu and you’re off to go!
Step 4: Considerations
This instructable was made with a available WiFi connection in, for instance, your garden.
You could consider setting up your WiFi on your Raspberry Pi in AP (access point) mode.
When you're out in the field, far from your home WiFi connection, you can connect your smartphone to your Raspberry Pi to control your GoTo mount.