6/2/2019 Telescope-mounted computer

03 June 2019

It’s been quite awhile since my last post, and I thought I would share what I have been working on lately. Here are a few photos of what will be a telescope-mounted computer system. The idea is by locating the computer on the telescope itself, we reduce the number of wires that need to run from the OTA and thus eliminate wire drag issues with tracking.

This first image is the original whiteboard image plan for the project:

You can see that we are planning on mounting this system to the top of the telescope, and that it will consist of the Power Distribution Unit (PDU), computer, focus controller and a wifi dongle.

For this project I have selected an Israeli-made Compulab Fitlet2 with an Intel J3455, 8GB of RAM and a 256GB M.2 SSD. This unit has also been fitted with a “facet” card that provides four additional USB ports bringing the total to eight ports.

As part of this project I realized that I needed a better approach to power, and thus I came up with this simple PDU design based on a panel-mount automotive blade-fuse holder. I decided to use an XT-60 connector for the supply and 5.5×2.1mm barrel connectors to supply individual components:

The whole system is mounted together on an aluminum plate, which was fitted with two holes to allow it to be screwed to the top Losmandy plat of the AT10RC OTA:

I ran an initial power-on test yesterday, and the above system was pulling about 0.95 amps at 12.9 volts. I expect the system power requirements will be higher once the QSI 583wsg camera is added with its TEC consuming a fair amount of amps for cooling.

At this point we are waiting for the telescope focuser to come back from repair with Starlight Instruments before more work can be done. After that we need to fix the collimation on the AT10RC, which was knocked out of alignment during recent mirror cleaning. Once that’s all done we should be in good shape to start imaging!