Lego Saturn V Rocket

Picture of reading Lego instructions

We finished our Lego Saturn V! Just in time to celebrate the 50th anniversary of the moon landing.

I like to pick projects to do with my kids. Sometimes it’s just a puzzle, and other times it has been Lego. This was one of those projects.

You can find a ton of reviews for this set online, and it seems like I am the last person to complete the set. The reviews are true – it’s a great set, well thought out, and very large. You can even add some lights and sound if you want.

Motivating your family

I have found my kids don’t necessarily want to do something if I ask them. Instead, I have had a lot of luck just starting a project in a common room, and they kind of gather on their own. For instance, I’ll start a puzzle and pretty soon someone shows up. They usually start by asking me what I’m doing. They might make fun of it. Soon they start watching. Then they start helping me. Coincidentally, this also works on my significant other 🙂

How to find one

These sets used to be hard to find, but that doesn’t seem to be the case anymore. If you are having a hard time find this set or another set like it, there are some websites that will alert you when a set is back in stock. In hindsight, I probably could have waited longer for a used set to show up online.

If you are looking to save a little money, you might do well to find a used set. For me, I was only interested in the rocket – I did not care too much about the lunar lander and stand. If I would have waited an extra year I could have saved a lot of money. You might do well to find a set that is missing some of these accessories. At least for me, tracking down missing parts can be part of the fun of constructing a set.

Here are some other Lego projects I have worked on:

Using Arduino to ignore button presses

arduino diagram

How I programmed an Arduino to accept a button press and then ignore subsequent button presses

I am working on an art project that involves a button. The button will start the device, but ignore any extra button presses for a set amount of time. This post focuses on my small journey, and a few things I learned along the way.

My Background

I have a very basic knowledge of electronics. I have an Arduino starter kit, and I played around with the tutorials until I understood the basics. After that I moved on. I figured I could always pick it back up again if needed.

The Requirements

  • Start a garage door opener (I’ll refer to it as the “opener” from now on)
  • Use the opener’s wired-button terminals/leads/pins to control it. These are the same leads that you would use hook up to a button on the wall in your house to use your garage door opener.
  • The opener has 2 terminals/leads – if they touch together, the opener will start
  • Use a button to communicate with the Arduino. It will decide if it should (or should not) use those terminals to start the opener

Hardware

I need 2 buttons: One to communicate with the Arduino, and the other one controlled by the Arduino. To do this I need something called a Relay.

What’s a Relay

A Relay is a fancy switch that is controlled by electricity. It does this with an electromagnet. Imagine a light switch – you add some parts so that if you hold a magnet to one side, the switch will flip. Take the magnet away and the switch flips back off. Wrap that into a box and you have a relay.

  • If no electricity is running to the Relay, then there is no magnet. The switch is off
  • If electricity is running to the Relay, then the electromagnet is on. The magnet attracts the switch to the other side and turns the switch on

You can hear a Relay when it switches. It makes a distinct “click” noise. You find them in a lot of everyday things, like your windshield wipers.

That’s the basics. Yet there are a few more features:

  • The Relay can do the exact opposite. It can be ON when no electricity is running, and turn OFF when the electricity is on
  • Relays are used to operate high voltage electronics, while protecting sensitive equipment. The Arduino can only handle about 5 volts. It could never power a household light bulb. To do this you wire the light bulb with the full power, and use a relay to control that power. The Arduino is safely behind the Relay, protected from the high voltage.

A relay typically has 5 pins:

  1. Input 1: the positive (+)
  2. Input 2: the negative (-)
  3. a common (or COM): this is one half of the thing you are switching
  4. Normally Closed (or N/C): when power is on, the switch is on
  5. Normally Open (or N/O): when power is off, the switch is on

I read a couple articles before this started making sense to me. This one helped me the most: https://www.instructables.com/id/How-Electronic-Switches-Work-For-Noobs-Relays-and/

My Relay

My Relay had no labels and looked different from most of the tutorials. I figured it out by connecting a couple alligator clips to a 9v battery. After connecting them to the pins on the relay, I listened for the click of the magnetic switch. After that I used my volt meter to determine which pins were Normally-Closed and Normally-Open.

The hardware layout

Relay Setup:

  • I connected my ~5 on the Arduino to one pin on the relay, and 5v on the Arduino to the other pin
  • The Common (middle) lead connects to one terminal on the garage door opener
  • The N/C (Normally Closed) pin connects to the other terminal on the garage door opener

Button Setup:

  • The button setup is like all the other button tutorials
  • I connected ground (GRD) on the Arduino to one end of the button
  • I connected ~9 on the Arduino to the other end of the button
My first time drawing a diagram in fritzing!

The Code

Intended behavior:

  1. When the button is pressed (or LOW) on ~5, I trigger a “button press” using the relay for the garage door opener (it starts)
  2. I then run a delay for a set amount of time
    • the delay allows my code to ignore everything until after the delay has finished

Quick notes:

  • I use the built-in LED on the Arduino to show when it is ignoring button presses (LED_BUILTIN)
  • I write debug messages to the serial. Not a big deal but it makes the code a little more busy looking
/**
 * Ignore button presses after accepting the first, for a set amount of time
 * Jason Jerome
 */

int gDoorPin = 5;
int buttonPin = 9;

String msg = "seconds to wait: ";
int secondsToWait = 20;

void setup()
{
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(gDoorPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);

  digitalWrite(gDoorPin, HIGH);
  Serial.println("Hi - ready");
}

void loop()
{
  if (digitalRead(buttonPin) == LOW)
  {
    Serial.println("button pressed");
    digitalWrite(LED_BUILTIN, HIGH);

    startOpener();

    Serial.println(msg + secondsToWait);
    delay(secondsToWait * 1000);

    Serial.println("done - ready for more");
    digitalWrite(LED_BUILTIN, LOW);
  }
}

void startOpener() {
  Serial.println("gDoor - activating");
  digitalWrite(gDoorPin, LOW);
  delay(500);
  digitalWrite(gDoorPin, HIGH);
}

Here’s a video of it in action:

This has been a fun project so far. I’m very happy to have most of the electronics figured out so early in the process. I can now move on to designing and building the other parts!

Rabbit Hutch

Rabbit Hutch

I repurposed an old shelf into a 2-level indoor rabbit hutch

This post is meant to expand more on some details of the build, some things I forgot, and some improvements I made since the original build.

You can view the original album here:
https://imgur.com/gallery/vOlcW

Wheels

I added wheels to make it really easy to move. There are 5 total – 1 for each corner and 1 in the center. I’ve done this with other heavier furniture in our house too.

The doors

I made the doors by making 3 levels:

  1. 1×2 inch pine boards, arranged in a rectangle
  2. Add wire mesh
  3. 1×2 inch pine boards, arranged in a rectangle going in the opposite direction

Here is a little drawing showing the steps coming together:

The ramp

I originally made the steps of the ramp using a small dowel rod. Unfortunately the rabbit broke (or ate) them. I later switched to 1/2 inch strips of wood that are much better.

A hay bin

A good way to encourage your rabbit to use their litter box is to provide some hay near it. Rabbits love to sit and nibble on hay while using the facilities.

The hay has lots of small pieces that fall through most of the hay holders sold in stores. So I made one that provides a small shelf to hold the small pieces.

Extra water

I try to encourage our rabbit to drink out of a bowl. Since this thing is in my living room it’s a lot quieter if he avoids the noisy water container. However, the container is a great backup which gives him multiple options for water.

On Finishing

This was a fun project to build. I had to be rather secretive about it, so after bedtime I was heading out to my freezing garage to work into the night. I had some setbacks, but was able to overcome them and learn something in the process.

Most of all, I don’t have to go outside to feed the rabbit. He’s often watching us eat dinner or watch TV. It’s not something my kids can forget about in the backyard.