0.5. Pre-Fab¶

ATTiny412
Pen Turning

ATTiny412¶

This is my ATTiny412 chip soldered using surface-mount soldering:

Setting Up Software¶

1.Open Arduino 1.8.19

2.Go to this link and download by pressing the three dots on the right side and selecting “download”

3.File → Settings and then paste http://drazzy.com/package_drazzy.com_index.json in the box after “Additional Board Manager URLS:” and press OK

4.Tools → Board → Board Manager… and then search “Mega Tiny Core”

5.Open the jtag2updi Arduino file from Downloads

6.Upload to Arduino Uno board using a COM port that is not COM1

7.Once uploaded successfully, open Arduino 1.8.19, select ATTiny412 as the board, and select jtag2updi as the programmer

8.Set up wiring, enter code in Arduino 1.8.19, and upload

One LED¶

Wiring¶

This is the pinout for the ATTiny412:

The yellow wires are connected to power, and the black, gray, and brown are connected to ground.

Code¶

This is the code to make 1 LED light up using pin 1 on the Arduino:

void setup() {
  pinMode(1, OUTPUT);
}

void loop() {
  digitalWrite(1, HIGH);  
  delay(1000);            
  digitalWrite(1, LOW);    
  delay(1000);
}

Challenges¶

The first time I tried to make one LED light up, my circuit would not work because one of the legs on my 412 chip was not fully soldered onto the board, so I went back and fixed the soldering. The second time, I placed the LED backwards in the breadboard, and since LEDs have polarity, that caused my circuit to not work. Once I flipped it around so the longer leg of the LED is connected to the resistor, the LED lit up and started blinking.

Two LEDs¶

Wiring¶

Code¶

This is the code to make the two LEDs blink in an alternating pattern:

void setup() {
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
}

void loop() {
  digitalWrite(1, HIGH);   
  delay(1000);              
  digitalWrite(1, LOW);    

  digitalWrite(2, HIGH);   
  delay(1000);              
  digitalWrite(2, LOW);    

}

LEDs blinking in sync:

Three LEDs¶

Wiring¶

Code¶

This is the code to make 3 LEDs light up like a traffic light:

void setup() {
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
}

void loop() {
  digitalWrite(0, HIGH);   
  delay(1000);              
  digitalWrite(0, LOW);    

  digitalWrite(1, HIGH);   
  delay(1000);              
  digitalWrite(1, LOW);    

  digitalWrite(2, HIGH);   
  delay(1000);              
  digitalWrite(2, LOW);    

}

ESP32¶

Pen Turning¶

1. Saw¶

I started out with a long stick of wood that I needed to shorten to the length of the brass tube in the pen kit. I needed to cut two pieces that were the same length. I used a table saw to shorten the wood pieces.

2. Lathe: Making the Hole¶

Next, I needed to use the lathe to do wood turning and create a hole in the middle of each of the wood pieces.

1.Mark the centers of the wood pieces using the diagonal line method. 2.Wear a face shield whenever near the machine. Headphones are optional. 3.Use the lathe chuck key to loosen the area that holds the wood.

4.Place the wood leaving some room between the wood and the edge and tighten it. Make sure to remove the lathe chuck key after tightening.

5.Turn the silver handle until the number reads 0.

6.Move the machine to the desired position and then move the silver handle in the back to lock the machine in place. I moved the machine so that the end of the metal tip was barely touching the front of the wood piece.

7.Turn the machine on by flipping the switch

8.Turn the silver wheel until you can see the metal tip poking out the other side of the wood.

9.Turn the machine off. Turn the silver wheel until the number reads 0 and the metal tip is completely out of the wood.

10.Use the lathe chuck key to loosen the wood holder and gently pull it out. Ensure the hole goes all the way through the wood piece.

3. Sand Brass¶

We needed to sand the brass tubes, ensuring that the outside was rough. The lower the grade of sandpaper, the easier it was to roughen the tubes, so I found it was best to use sandpaper with 60 and 80 roughness. I struggled with sanding the brass enough because I started out using sandpaper that was not rough enough. After switching to 80, it became much easier, and the sanding was much more efficient, and then once I switched to 60, I finished quickly.

This is the kit we used to make the pen.

This is the sandpaper with the brass tubes.

These are the final sanded brass tubes.

4. Gluing the Brass Tubes¶

I used super glue to glue the brass tube in the wood and then used activator to speed up the drying process. I tried to be careful to not use too much glue because the brass tube needed to be fully clear in order to continue and use the lathe again.

5. Drill Hole¶

I still managed to use too much glue, so I needed to drill through the brass tube to clear it out enough for the mandrel to go through it.

I used this drill:

I used this tool to hold the wood piece in place while I drilled:

6. Lathe: Rounding the Wood¶

1.Wear a face mask and face shield anywhere near a running machine because the wood pieces can go flying, and you do not want to inhale wood dust.

2.Place 1 baron, 1 piece of wood, 1 baron, 1 piece of wood, 1 baron and then the gold disc on the metal pole that goes into the lathe.

3.Use a wrench to tighten the metal pole in place until it will not turn anymore.

4.Turn the lathe on.

5.Use the square screwdriver to get rid of the excess wood around the outside. Keep using the square screwdriver until the wood piece gets to be slightly greater than the size you want it to be. Rest your left pointer finger in the finger slot while holding the metal part of the screwdriver with your left hand and the end of the screwdriver with your right hand. Slowly move the screwdriver back and forth horizontally, tilting the metal tip slightly upwards. Try to move the screwdriver evenly across and make the wood roughly the same size for each piece.

6.Switch to the circle screwdriver. This will help round the edges of the wood and create a smoother, rounder look. Rest your left pointer finger in the finger slot while holding the metal part of the screwdriver with your left hand and the end of the screwdriver with your right hand.Slowly move the screwdriver back and forth horizontally, tilting the metal tip slightly upwards. Try to move the screwdriver evenly across and make the wood roughly the same size for each piece. Once the pieces are roughly the same size, you can choose to round the edges making the front and back ends of one piece rounded inwards creating a classic front-of-pen look.

7.Once you have the desired shape, select around 5 pieces of sandpaper ranging from 300 grit to 2000 grit. In increasing order, hold each piece of sandpaper on each of the wood pieces for around 20 seconds, sliding it slowly back and forth horizontally. Make sure to sand the ends too, and sand each piece evenly. I had used the lathe to make my wood pieces pretty thin, so I had to make sure not to use too rough sandpaper for too long because that would make my wood pieces too thin and possibly break.

8.After the wood feels even and smooth, pour around a teaspoon of wood polish on a paper towel and rub the paper towel back and forth horizontally across both pieces of wood for around 20 seconds, making sure to cover all spots. I recommend folding the paper towel in half and making it smaller so that it does not get caught in the lathe.

9.Turn the lathe off. Use the wrench to unscrew the metal pole and gently remove the barons, gold disc, and wood pieces.

Here are my final sanded and polished wood pieces:

6. Assembling the Pen Kit/Using Pen Press¶

Pen Kit

1.I used the Rockler Gold Slimline Pen Kit to make my pen. With the wood pieces and the remaining kit materials, I used a pen press machine to assemble the pen. The pen press pushes the materials securely together.

2.To assemble the front half of the pen, align the cone-shaped tip with the thicker wood piece that you want at the front. Place the cone-shaped tip into the small circle in the white part of the pen press and push gently to hold it in place. Once aligned and correctly positioned, push the pen press and then pull it away. Make sure that the tip is firmly pressed into the wood.

3.Take the silver tube and push the gold end into the front wood piece until the wood barely touches the black line. Once you think it is touching the black line, take the ink tube and place it through the tube to make sure the pen tip is out enough to write with.

4.Set the front half of the pen off to the side.

5.Take the cap and clip and place that into the other wood piece. Push these components together to make up the back part of the pen. I struggled with lining the pieces up correctly for these pieces, but after pushing it in a little, my teacher was able to help me align it enough to continue pressing it all the way.

This is my final pen back half:

6.Use the pen press to press the front half of the pen, the center ring, and the back half of the pen together.

Last update: February 26, 2025