After some time of using the AstroBox M4 - FriendlyElec NanoPi M4 - it is time for a little summary...
So far my the experience with the board has been great!
The AstroBox works well - finally this is a board which delivers enough power to drive what is needed. Quite a lot of stuff actually:
- INDI + Kstars with Ekos (compiled from source)
- Lin_guider (compiled from source)
- Celestron Nexstar mount
- Various scripts (bash, python)
- Relays controlled by GPIO
- Heater controlled by onboard PWM
- Canon cameras via gphoto2
- Pentax DSLRs via pktriggercord
- QHY5 guiding camera used directly by Lin_guider, but also via INDI...
- DreamFocuser via INDI
- Astrometry.net installed locally
- TurboVNC - by far the best VNC server! (compiled from source)
All the above runs in Armbian (Debian) and the entire Debian repository is available. I've choosen to compile INDI, Kstars and other software to have the latest versions. In some casese (e.g. TurboVNC) the software is not in the repositories.
Ekos functionality
I wanted to use more of Ekos and less of various scripts. Basically it is just working, however I did not ditch my scripts completely.
- Autofocus = DreamFocuser + Canon 400d =
- PROS: works and does the job automatically (stops guiding, finds the star, iterates to reach the best focus)
- CONS: I can achieve better focus using Bahtivov mask; sometimes it thinks a noise is a star and focus goes completely off (can't be left unattended)
- Platesolve to synchronize and to slew to your target = Nexstar + Canon 400d =
- PROS: works and achieves very good precision; just give it target name or even FITS file with your earlier photo; works offilne
- CONS: sometimes it does not work with FITS (some my files probably miss important data); with my mount it can try ten times until it achieves the target with good enough precision
- Autoguiding = QHY5 + Nexstar =
- PROS: all in one program and well integrated with other functions; can use external guider (Lin_guider or PHD2) and still integrate
- CONS: has tendency to loose the guiding star; external guiders allow more control over guiding parameters
- Driving the entire session - scheduler
- PROS: could potentially automate entire sesion
- CONS: needs a quality mount, quality cameras and telesope to work reliably; in my experience it is quite picky (e.g. autofocus failed -> entire session fails or autoguiding lost the star -> entire session fails etc.); still better to run individual tasks manually...
To summarize
The NanoPi M4 was one of the first SBCs withe enough horsepower to drive astrophoto sessions. IMHO it is currently the best! Only few months ago the RPi4 became available and now the solutions like Stellarmate for RPi4 start to appear. But NanoPi is still better: there is a lot of development around mainlinig the Rockchip boards. As a result NanoPi M4 currently can work with pure, open source Linux! No vendor lock-in. Runs 64bit (ARM64 aarch64) Linux - with the necessary software installed directly from repositories (few exceptions can be compiled - easy). I can use all 7 USB ports (4 are USB3). The onboard wifi and bluetooth work as well, without any special drivers. Performance wise it is equal or better than RPi4.
I bougth another such board, this time with 4GB memory. I will use it as tablet (with a touchscreen). I already installed Arch Linux on it and experiment with Panfrost drivers (open source 3d for ARM Mali)...
Next post: some pictures I made during this half year... Stay tuned ;-)
