I love using Ekos on RPI3 for astrophotography. For guiding I have tried linguider, and the internal Ekos guider, and typically use PHD2. PHD2 in general will give me okay guiding. If there is no wind the stars are round at F10.
Last night I tried to debug some guiding issues and use PHD2 on a Windows PC. The performance was amazingly different. PHD2 was using the ST-4 and the ASI174 camera directly. On RPI3 I typically use the indiserver through local host (via the web server), and have been playing with either the ST-4, or the USB and pulse guiding.
PHD2 on the PC was giving me guiding that was so flat I thought something was wrong. The y graph was set to the 2" and the RMS Error Total was below 1, something I have never seen on the RPI3. Getting it to 2 is what I typically try to get on my CGEM-DX using RPI3. I am assuming the difference is due to the more powerful PC and being able to process the data faster with more than the 1GB RAM on the RPI3.
Is there anyway to get this kind of performance on the RPI3? I thought maybe using the subframe on the RPI3, yet that does not work and when trying it out it even crashed PHD2.
Perhaps linguider or the internal guider, if I tweak it, can provide better guiding?
Not sure if extra cables were needed - this weekend I got hold of an outdoor router (e.g. TP-Link M7350), and eventually managed to address / chain two Raspberries to run the telescope-simulator on one, and the ccd-simulator on the other - which did not even require a sim-card. So I can use my laptop to run Ekos in the field (without Ethernet cables or VNC), and limit the Raspberries to run the drivers.