I just have some progress with my EAA activity and would like to introduce my Ultra Basic EAA setup. I hope to practice EAA with the minimal investment, knowing that there will be compromises.
Essentially my EAA setup is divided into 2 modules: The imaging module and the tracker module (photos enclosed). They are standalone modules.
For the imaging module, the lens is a DIY refractor. I took the main lens out of a old Celestron 7x50 Binoculars and connected it with some PVC pipes. The focal length is 180mm, so f/3.6. The camera is a Raspberry Pi HQ camera, using a Sony IMX477 sensor. Resolution is 4056x3040 max and pixel size 1.55um. This camera must be used with a Raspberry Pi, which happens to be a Pi 3B+ in this case. I also use a HDMI adapter board so the connection between the camera to the Pi is via a robust HDMI cable, not a delicate flexible flat cable. Apart from controlling the camera, the Pi 3B+ also perform live stacking using ASTAP. Some python scripts are used to execute all the functions and provide a user interface. The Pi 3B+ also serves as a WiFi hotspot so I can connect a smartphone via some remote desktop app to control Pi and view the results. The whole module is powered by a 5V mobile power pack.
The tracker module is built around a normal EQ mount which I acquired from second hand source. I add a stepper motor to the RA axis for tracking while the rest are still manually adjusted. The stepper motor is driven by a Arduino using a very simple script (just straight 1 speed stepping, no fast forward whatsoever). The power supply is a 12V lead acid battery which power the stepper motor directly and also drive a 5V regulator for the Arduino. The tracker works completely independent of the imaging module and there is no communication between them.
A smartphone is used as the overall control. Preview for locating the target, execute the capture commond when target found, then view the live stack results.
As the Pi 3B+ is not powerful, the images are captured with a 2x2 binning down to 2028x1520 and in PNG format. File size is about 3M each sub. From the advice of Han (author of ASTAP), the image need to be further bin down 2x to achieve successful alignment for live stacking.
I use 4s per sub as a base and capture about 40 subs for 1 target. The trial last evening was rather successful. I "observed" 3 DSOs, taking total 120 subs and all stack successfully. 100%. I live in big city with Borte 8/9 sky and EAA is really helping me out.
I have enclosed the live stack images of the 3 DSOs. Each are live stack output of 40x4s, with UHC filter installed. The targets are M31, M103, NGC889. The optics are quite bad though.