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I’ve had the April Cyber City Circuits soldering subscription box sitting on my desk for a week. This has been driving me crazy as I love these little kits. But I promised myself I would get caught up with all my subscriptions before moving on to new ones. Well, that finally happened! (now I have to get caught up on the dozen or so non-subscriptions posts to do, I do a lot more projects than subscription-based ones).
This month’s soldering kit requires a lot of soldering. That’s great! This is the perfect time to get practice soldering. Plus, the finished project is a fantastic Tic Tac Toe game.
The Tic Tac Toe kit
The Tic Tac Toe kit from Cyber City Circuits is perfect for anyone wishing to practice soldering. There are dozens of resistors and LEDs that have to be soldered onto the board.
Below is a view of the components in this kit:
This kit is also an excellent opportunity to learn about various components. To me, the star of this particular kit is the MCP23017 port expander (Amazon affiliate link). The Arduino Nano driving this game is an amazing microcontroller. But even with its significant amount of input/output pins, it would not be easy to do projects such as this without a port expander. The MCP23017 gives the Nano another 16 input/output ports. Plus, it only uses two of the Nano pins to get those additional input/output ports (via I2C).
Cyber City Circuits have posted a tutorial and video for the Tic Tac Toe kit. The tutorial is good enough I won’t bother going through the steps I took to assemble the kit. I will only highlight how I chose to do the LEDs.
Here is the order I did the LEDs in:
- First, I soldered the four corner LEDs. I soldered the negative lead for each of these. I then heated that solder joint and firmly seated the LED into place. Then I soldered the positive lead into place and trimmed the tips with flush cutters.
- Then I went row by row, starting from the top.
- First I inserted a row worth of LEDs (making sure to use red or blue appropriately).
- Then I soldered the negative (bottom) lead into place.
- Then I heated the solder joints one at a time and firmly seated the LEDs into place.
- Then I clipped the negative leads down.
- Then I soldered the positive leads.
- Finally, I clipped the positive leads.
I did the above procedure to help overcome my shaking hands. I didn’t have to worry about getting my soldering iron into weird positions to avoid a forest of leaves. I only had to deal with one row of leads at a time. In my younger (and less shaky) years, I probably would have done this differently.
I want to reassure anyone afraid to solder that it is OK not to have perfect soldering joints. Yes, you want to avoid cold joints. But soldering, like any other skill, takes time to perfect. In my case, I am trying to perfect applying the solder as my hands shake. I am working on one consistent motion. If I want more or less solder, I will use different sizes of solder. That way, no matter what, I usually hold the solder in place for the same amount of time. I haven’t perfected this move yet, but I’m getting better.
3D printed case
This month’s project was so packed with components that there was no room for mounting holes. Mounting holes would have made it easy to create a back cover. But there is more than one way to create a case. For this project, I created a ledge in the case for the PCB to sit on. I then made a groove for the board to sit on. The ridge above the board is just enough to hold the board in place.
Below is a picture of the case I designed in Fusion360. The STL can be downloaded from Thangs. You can see the ledge the board sits on top.
The board snaps into place. It seems like it might be too tight, but it isn’t. Here is a look at the board inside of the case.
Testing the game
Below is a short video of me testing the game. I used a portable USB phone charger to power the board via the USB Mini connector on the Nano.
The game works great. Plus this is another project that I think the nieces will get a kick out of playing when they visit.
Time-lapse of the day
Today’s time-lapse video is another Hex3D creation. The following video shows a Mandalorian Helmet being printed upside-down on my Ender 5 Plus. It was printed with White PLA+ from GST3D and took about 80 hours to print.