Need Instructions for Connecting the Components Electrically


While we wait for Linux command help on installing and testing the POCS software on the Intel NUC, we would like to proceed with wiring all the components together electrically.

Are there instructions for this, so that we can connect up the soldered boards, the cameras, and the computer? On the website under “Instructions”, the “Camera Box Electronics” and “Computer Box Electronics” links are basically empty.

Our goal is to get our unit into test mode by the time we put the PANOPTES poster up at the SAS conference in three weeks. We need to get the NUC finished and the unit assembled electrically as soon as possible. (We are deferring things like the weather-proofing and permanent mounting until later because they are not critical path).

We are anxious to plug it in, have it point at some coordinates in the sky, take a picture, and gather some data, if only in test mode!

Thank you all for any help.

I figured it out by looking at the photos of PAN001 and at the Cables sheet in the Electronics Parts spreadsheet. From that I figured out what connections were needed, and wrote the PANOPTES Baseline Unit Description page that is now one the website.

The lengths of the various cables aren’t well spelled out. Regarding the long cables:

  • The mount power supply (DC cable with barrel plugs at each end) and the mount control serial cable (RJ9 to RS232 cable, supplied with the iOptron mount) need to be long enough to go from the inside of the control box, out through one of the smaller PVC pipes on the side of the Pelican case and over to the mount. The exact length depends on your setup, but I’d guess 6 to 9 feet.
  • The camera box power supply (DC cable with barrel plugs at each end) and the camera data cable (USB cable, USB-A at one end, various choices for the other end) need to be a few feet longer than the previous two cables. I used 10 feet as the distance, which was plenty.

Inside of the control box things are of course shorter:

  • I did build some custom DC power cables, but preferred to use pre-made cables for most situations as they are likely to be more reliable (better solder joints). For example, Amazon part B00DX6ZUBM is a 2 foot long cable.
  • I soldered a 2.1x5.5mm male plug to the end of the fan’s wires and positioned the power board close enough so that short cable length was sufficient.
  • For powering the NUC I created a special DC cable with different barrel jacks at the two ends, about 2 feet long. A 2.1x5.5mm male plug is needed at the end that goes to the power board, but the NUC uses a different size barrel jack/plug (2.5x5.5mm, I think, though I don’t know if all NUC’s use the same size). I think the instructions call for cutting the DC end of the AC/DC adapter that comes with the NUC and adding a 2.1x5.5mm plu to the cut end. That of course is a one way operation, so you can’t readily use the adapter after that. So I went to a store that sells these things and found one that fit the NUC and built a cable of my own.
  • Two USB-to-RS232 adapters are needed, one for the AAG Cloudwatcher and the other for the iOptron mount.
  • I created a short power cable with spade terminals for connecting the battery to the power supply.
  • I cut a standard AC power cable from an old device for powering the system. Around 1 to 2 feet long. I cut the sheath back away so that the 3 interior wires were visible, allowing me to slip the AC sensor (a vaguely ring shaped transformer) over the hot wire.

Inside of the camera box, we need several cables:

  • Two short USB cables (USB-A to USB-Mini) going from the USB hub to the cameras.
  • Two short DC power cables going from the camera board to the Canon battery adapters (i.e. the plastic boxes that go in place of the batteries). Not knowing the exact type of plug at the end of that cable, I did cut the cable that came with the Canon AC adapter (third-party product), and added a 2.1x5.5mm plug at the cut end.
  • I used a DC splitter cable to power the camera board AND the USB hub (not the hub in the original parts list). This connected to one end of the long DC power cable mentioned above (power board to camera box).
  • A short USB-A to USB-Micro cable from the USB hub to the camera board.
  • The long USB cable from the control box to the camera box that I used was a USB Extension cable (USB-A male to USB-A female). To connect the hub, I used a short USB-A to USB-3 B cable because the hub I used is a USB 3 hub.

I hope that helps. It isn’t complete as it is from memory.

Thank you, James! Great job, doing this from memory. Hopefully what you have written can serve as the basis for the instructions on this. We will take notes of anything that we have to change.

We will give it a try later today and hope to have progress to report at the meeting this afternoon!

I recently tested the UA panoptes electronics. Before assembling everything together and figuring out the control box real estate placements, I wanted to confirm the electronics were working. I didn’t build everything (NUC connector, weather station missing), but the important thing is that everything turned on.

Here’s some comments I have from James’ description:

  • For the battery’s power cable with the spade terminals, I used 18 AWG wire. I selected a spade terminal plug with an appropriately sized wire entry. I crimped the wires into the spade terminals to make a good connection.
    FYI - I have access to a full electronics shop at UA Steward Observatory, so I’m not sure what’s the alternative for doing this part without the crimping tool.

  • The NUC uses a 2.5x5.5mm barrel plug. I brought the cable to a local electronics supply store and asked for a similar plug. Although there are 2 little notches for the inner diameter for the NUC-supplied wire, a barrel jack without the notches should still work, so long as the inner diameter is 2.5mm. According to the store attendant, they’re the same and the only difference is production.
    FYI - I didn’t get to test this wire before I left.

  • Our fan has 3 wires (red, black, yellow). However, the barrel jack only requires 2 wires. I tested which wires sequence would work by connecting it to a DC power supply (the battery serves as one, too). I hooked up the DC supply’s black terminal with the fan’s black wire and I tested the yellow and red wire with the DC supply’s red terminal. I think it was the red wire that worked. I used some screw-on barrel plugs that Luc provided to me. It will require soldering on longer wires for the fan to reach the power board, so that’s on the TODO list.

I hope this helps for some parts!