As I said in the previous post, I should have soldered the LCD and LED wires to the second board before wiring it to the first board. I didn’t want to unsolder the board-to-board wires, but I also didn’t want to break them by bending them too much. So once I had measured, stripped and tinned the LCD wires, I made a gentle bend to expose the solder points.

And here are a couple of photos of the first two boards wired up and with Arduinos plugged in.

Some notes:

• I had to disconnect the wires from the relay bank in order to continue.
• Each time I need to solder wires to a new board, I need to pull the wires off of the LCD and LED for any boards that are connected to that board. For example, you can see in the photos above that in order to solder new wires to the second board, I had to disconnect the LCD and LED wires on the first board
• The gray and white wires on the second board (the wires for DC and SDCS) are almost too short to make the connection. I’ll have to watch out for that as I progress.

My set of wires arrived today. I wanted to get 9 different colors, but only 7 different colors were in stock when I ordered them, so I will make do with that.

Because I am using solid core wires, I want to make them the exact length that is needed to connect adjacent boards. To accomplish that, I came up with the following procedure:

1. Attach two adjacent boards to the control panel. The downstream board will not have the Arduino sockets soldered to it yet.
2. Measure, cut, and strip each of the wires that connect the two boards.
3. Remove the two boards from the control panel
4. Solder the Arduino sockets into the downstream board
5. Solder the wires between the boards
6. Reinstall the two boards to the control panel to ensure the wiring accommodates the board placement
7. Check all connections for continuity

Here is a series of photos of the process:

Here is a detailed description of Step 2 from above:

1. Strip one end of a wire
2. Bend the stripped portion 90°
3. Place the stripped portion into the appropriate hole on the downstream board
4. Cut the wire a little past the hole on the upstream board
5. Use a utility knife to mark where to strip the cut end of the wire
6. Strip the cut end
7. Bend the newly stripped end 90°
8. Place the wire into the boards and move on to the next one

In the previous image, you can see why I wanted 9 colors. I wanted unique colors for all of the switched inputs. But instead I’m just using blue and white twice.

I had a nice little box delivered today.

Here is a side-by-side comparison between one of the old boards and one of the new boards.

And here are a couple of images with the boards close together to illustrate the increase in the width and length of the new board.

Finally getting back to the project after over four months. I had soldered the wires to the first four boards, but had run into some issues with wires breaking. I repaired them as best I could, but I decided it would be wise to do some continuity tests before proceeding.

The good news is that I didn’t find any connections that weren’t supposed to be there (no cross-pin solder mistakes). The bad news is that there were several broken connections. I tried repairing them, and was successful with a couple, but in the end I couldn’t get them all connected properly. Here is what it looks like:

I have decided to try using single-strand wires instead of the stranded wires I have been using. I think that will reduce the risk of breakage. I’ll probably also order more circuit boards rather than attempting to desolder the four pictured here.

So, I’m back to waiting for parts (I can get back to it as soon as I have the wires, even if the new boards aren’t in. I’ll just start with the other boards I already have.)

So far I have only soldered the pins to 8 of the 20 arduinos. In the meantime, I drilled the holes for the standoffs for the circuit boards, and installed the standoffs. I don’t have any photos from those steps, because I was filming it with the intent of making another time-lapse video. But the footage was pretty disappointing, so I’m not doing that.

The process for drilling the holes was as follows: I placed the circuit boards where I wanted them, and used a sharpie to mark the locations of the holes. I put both control panel layers together and held them in place by installing a couple of the controller buttons. Then I drilled all the holes with a bit wide enough for the threaded part of the standoff. Then I separated the two layers and re-drilled all the holes in the top layer to 1/4” to accommodate the nut for the standoff.

I don’t know how it happened, but for some of the boards, the holes did not line up.

But as long as each board has at least two screws securing it, I am happy with it. Most of the boards did line up in all four holes.

As seen in the previous photo, I also started soldering the headers to the circuit boards in between getting all the standoffs installed. I have since removed the other boards and also soldered on he headers. Here is a picture with some arduinos plugged in:

I have also soldered the control and power wires to the first board, and wired them in to the relays. I completely redid the relay setup because it was kind of ugly the first time.

For reference, here is the old, ugly relay wiring:

I received my new batch of 20 Arduinos. So I’ll be spending some time soldering the pins into them.

As before, I’m using my prototype breadboard to hold the pins (and to provide a little bit of heat dissipation). If I don’t solder the 90-degree comm pins on first, I can set up 4 Arduinos at a time for soldering.

Here are the first four, all soldered up (minus the comm pins on three of them)

Before laying out where the circuit boards will be mounted, I had to find a way to safely turn the control panel board over without losing or breaking the LCDs. I couldn’t just remove them since I glued the SD extenders to them and then glued the extenders to the panel. I decided to try taping a piece of paper over the LCDs to keep them in place. It seems to have worked well enough.

For the placement, I wanted each circuit board as close as possible to the LCD it would be controlling. This worked out better on the bottom row, because there is more room and there are only four buttons to worry about. Here is the placement I have for now:

Here I have added some lines connecting each circuit board to the LCD it will control. This is roughly where the wires will go.

Then I added blue lines to represent the control and power wires that will come from the relay bank and go to all the boards.

The next step is to mark all the holes for the circuit board standoffs and start drilling!

Sometimes, you have to tear something down to build it back better. Here is the tearing down part.