New eFinder ‘Lite'

Having developed and improved the eFinder, it had reached a good point to leave it as is. Quite a few people around the world have or are building their own, and it seems to be a stable design now. So what next!

I had previosuly tinkered with the Raspberry PI HQ camera (cheap and small) but left it in favour of the ASI 120 and its very good sensitivity and low noise. But others have had success (eg PiFinder) so time to have another look. Also, the Pi Zero 2 W was worth a look as an alternative to the Raspberry Pi4 or 5. It has a quad core processor, GPIO pins camera interface and can run Debian 12 which I use in eFinder. Drawbacks are slower clock speed, very low RAM size (512MB) and one only USB port.

Along with the change in camera and processor, I decided to look at Tetra3 as an alternative to astrometry.net as the plate-solver.

A fuller description of the build and how to copy it is here. But here are some ‘highlights’ …

  • With a faster lens (25mm f1.2) the Pi HQ camera can produce acceptable images with 1 second exposures.
  • The Pi Zero 2W will run my eFinder code, after a bit of slimming down. It's slow to boot and load, but once done it is OK.
  • Tetra3 is amazingly fast. It does need care in generating its search database and setting its solve parameters but once that is worked out, I can get solves in 100ms!
  • The power consumption of the eFinder LIte is so low it can be powered via the USB cable connected to the Nexus DSC port.
  • A really simple solution. One assembly and just a single cable to the Nexus DSC.
© AstroKeith 2024