Thursday, July 11, 2013

Hacking with your child

Kids want to be involved in adult activities.  This is so fortunate!  My son has started taking interest in my microcontroller devices.  If I could involve him in building some circuits, I get more time to play with electronics. As a bonus, this would give my wife some free time and distract my son from his usual business of hiding valuables and destroying property.

So we set out to build a simple circuit: we chose a blinking lights circuit.  The core of the circuit is the NE 555 chip in astable mode: with a single LED blinking. If you want to do this, follow along. The point of this post is not what circuit to build, rather it is how to build this circuit to keep the interest of a very young child.

Some overall guidance:

  1. Simple circuits: A friend at work suggested this idea. Select a trivial project that you can get done in no more than 15 minutes. Everything takes longer with a child, and they have shorter concentration spans. Aim to finish in 30 minutes with the child.
  2. Prepare in advance: Depending on how old your child is, you might want to prepare most of the circuit in advance. Remember, you don't want to debug things with a potentially cranky child. One trick I use is to wire everything with long wires and tall leads on the components and get it working. Once it is working, get your kid along and switch all the ugly long wires for short ones, trim the leads, and have the child put the most critical component in, which gets everything going.
  3. Involve the child: The idea is to get them to participate and get a feeling of accomplishment.
  4. Avoid theory: At this age, the child is too young to understand what a resister does. Get them to love the process.
  5. Light-based circuits: Light-based circuits work well. Sound-based circuits get annoying for parents.
  6. Real pieces: The more this looks like a real grown-up thing, the more some kids will be interested. Avoid tacky childish substitutes.
  7. Future hacking: Keep some room for future hacking. Extra room on the breadboard, potential to add a switch for some simple interaction. This will come in handy when the child starts to lose interest, or asks to make another circuit.

The goal: get a 2-3 year-old child to see how a circuit board is built and get the child familiar with some components.
  1. This is the circuit we built. Open the page and print it out.
  2. Obtain twice the parts: a breadboard, a 9V battery and clip, a 555 chip, a capacitor, three resisters and one LED.   You are getting twice the parts because young kids love holding on to some parts. You want a spare sets of parts both to account for loss and for a child getting very affectionate towards a 1uF capacitor.
  3. Prepare the board and make sure you know what you are doing. Your electronics chops might be weak, check if you can get the circuit working.
  4. When your child is free, motivate the idea. "Do you want to make a NEW blinky-blinky?" "Oooh, shall we make a NEW blinky-blinky?". Stress on creation, stress on the fact that you are doing it together. If the child is not interested, wait for an opportune time. Consider involving your spouse in motivating the idea: the child might be going through a mommy-phase or a daddy-phase. It could be that your child just doesn't care about circuits. Respect your child's interests.
  5. Get the child to sit down on the dining table high chair. Consider strapping the child for everyone's protection.
  6. Show the child all the components, name them. You'd be surprised what they can remember. 
  7. Start putting the components in, carefully clipping leads and wires to a precise fit. You want all the components to fit tightly on the board. With any luck, this will be your child's favorite toy for a few weeks. That means high G-forces, and being carried everywhere. You don't want to drop components all over town.
  8. If your child wants to put in components, allow it. Allow incorrect component placement. Don't chastise. Instead, gently correct the component while saying, "Hmm.  That's good, but how about we put it this way..."  Any negative words might turn your child away from this entire affair. And success here can justify that $1000 oscilloscope to your spouse. So be patient, and avoid evil thoughts.
  9. Keep an eye on your child's interest level. If they look bored, stop. Return another day.
  10. Leave the 555 IC for the very end, and perhaps get your child to put it in.
  11. Hopefully, you get the project done. Congratulations! If it helps, call the breadboard something special to enforce that something new was created: "Wow, this is a 555-blinky-blinky!"
  12. Allow your child to hold the breadboard, toss it around. Don't disapprove of rough handling. This is your child's toy, not yours.
  13. Ideas for future hacking:
    A second LED that turns on when output on pin3 is low. You'll need a pull-up resister and an LED. Try a different color if possible.
    You could add another 555 for two extra blinking LEDs. Choose a different period of oscillation.
    You could include a push-button switch to force Pin3 high to keep the LED on as long as the button is pressed.

Things you might do differently depending the age and personality of your child:
  1. Solder: I used a breadboard rather than soldering because the end-product should be non-sharp, and should be child-friendly. Depending on the age of your child, you could use this as an opportunity to teach some soldering.
  2. Explanation: If your child has more background, perhaps from electronic toys, consider explaining what the components do.

Credit: Many people at work for suggesting projects and giving guidance before I started out. You know who you are. Thanks!