Sunday, September 20, 2015

Talking Moose

Lately I've been fooling around with Bluetooth speakers so I suggested that we take some of my daughters toys and make it talk. She was obviously very excited. Imagine if someone suggested this when you were a kid. I'd personally had gone nuts. Well, she chose her dear Moose. 

So I went to buy a cheap'n'small bluetooth speaker for 17 euros and we started by makingthe bluetooth speaker talk using the Mac's fabulous say command line tool. First we connected the Bluetooth speaker by fiddling with the Mac's Bluetooth preferences. After that, the speaker is ready to use. Now, when you type something like

    say "Hello world"

You'll hear speech from the bluetooth speaker. There's even a bunch of different voices available and you can add more from the Text-to-speech preferences. For the Finnish language, there's a nice voice called Mikko. To use a specific voice, you do like

    say -v Mikko "Huomenta Suomi!"

And it was fun, once again. We've played with the say command before, but now the sound comes from a different box, so it was even more fun. Even our 3-year-old made the box talk. She can type her own name and learning more words every day.

Then I suggested we break the bluetooth speaker to pieces, just for the heck of it. And sure we did. We found a lithium battery, a circuit board and a speaker element. And I do find my daughter to be much like me when I was a kid. I always broke things to pieces and usually was unable to put them back together. We, however succeeded also at putting the speaker back together too. And yes, we tried if it works when in pieces too.

Later today, she came back and asked whether we are going to make the moose talk. And we stuffed the speaker into the Moose's butt. Now it speaks. Through its butt. Great! We even added some velcro so that you can close the gap and hide the electronics. And open it to recharge the speaker via USB.

By the way, you can actually connect several bluetooth speakers to your Mac. And you can address each of the individually using the -a parameter of the say command. What this mean in practise is that you can make a theatrical play with several soft toys speaking (through their butts) with different voices, by programming! 


Monday, September 14, 2015

Hello Ruby!

A while ago we got mail.

The long-awaited Hello Ruby book by Linda Liukas arrived! We read it as a good-night story the same night and both the girls (6 and 3 years) seemed to love it. Even with about 60 pages of story, it was an easy and quick read and even the 3-year old was all ears and had no problem concentrating. 

I was expecting a bit more "programming" in the story though. There are references to algorithmic thinking (Ruby thinks like a programmer), but without extra explaining, the kids won't notice that. The references to Python, Django, Snowleopard, Androids et al are also cute but don't ring any bells to small kids. Not sure that it makes sense to add that kind of a layer on the story.

Nevertheless, the most fun part in the book are the excercises though. From page 65 or so starts a "workbook" (not sure about the wording as my book's in Finnish) section, which is a real treasure chest full of fun and graphical programming exercises that you can do without a computer. This is the section that makes the book twice worth its price even if there wasn't a story at all!

Working on the 1st exercise

The exercises may seem simplistic, but at least for my quite-a-bit experienced 6-year old coder girl, they were just perfect. Easy and fun. We covered the first three exercises in half an hour or so. The first exercise was about writing written instructions for stuff like eating breakfast. Below there are the 6-year old's instructions. She even managed to make a loop to make sure that all the oatmeal gets eaten. She wasn't sure how you make a loop in this Finnish pseudo-language, and asked me how to "make a repeat" in Finnish, as she didn't know the right "coding words" in her mother tongue.

The exercises involve not just writing step-by-step procedures, but also breaking things into parts, boolean logic and so on. As an extra, she got to draw Ruby in her weekend costume, the rules of which she had to write in exercise three. You can probably guess the rules from the picture?

And how about the 3-year old? She was busy too, and also drew a picture of Ruby.

Ruby pictured by 3-year old artist

So, Ruby is not just cute, but smart too. Well done, Linda!

Tuesday, May 26, 2015

The Milatron

We haven't coded much lately. Seems that she's interested in hardware at the moment :) And stuff like sports and music. With regard to music, we've been building a thing I call Milatron.

It's a custom electric instrument that we designed earlier (see my previous post). The idea is that we use an Arduino microcontroller to produce different sounds through a speaker, when you press one of the 8 colored buttons. Simple enough. We found a suitable cookie box to use as the chassis and decided to use a 4 inch speaker element which is way too heavy for our use but later on proved to be a good choice.

First, we had to measure, draw and cut a hole to the chassis for the speaker, and install the speaker with bolts. She did most of the hard work, of course.

Then it was time to drill holes for the keys. At this point you could already see that this thing is gonna look awesome. 

She installed the keys mostly by herself and did all the soldering too. She just loves soldering!  

We added the Arduino and a breadboard inside. The breadboard had a sticker surface on its bottom so it could be nicely fitted on top of the speaker. At first I added a resistor between the Arduino and the speaker to turn down the volume a bit. Later we replaced the resistor with a potentiometer so that you can adjust the volume to your liking.

We installed a 9 volt battery which is held in place by the huge magnet of the speaker. So the big speaker turned out quite handy in many ways. It also gives the gadget a considerable weight, so it doesn't feel like your average children's toy.

Here's the Milatron now. It's tuned in D major and makes terrible noise. It even has kind of a polyphony. 

We did some experiments with software-generated sound before we started working on the actual instrument though. But I decided writing the actual Milatron software myself, because generating waveforms with different, accurate pitches isn't actually trivial. A bit too much for a 6 year old, I'm afraid. I think the main thing is that she knows it can be done.

All in all, we spent something like 3 nights working on this. Good times! And the monstrosity is still in active use, a few weeks after its birth. We are planning on adding extra features like pitch bending later... 

Maybe I should post a video of how it sounds?

Saturday, March 21, 2015

Lesson 67 - Modding Switches

Today I got a shipment of electronics. Me and my little girl were both excited to open a bunch of envelopes to see what's inside; we have been waiting for some more Arduinos and mechanical switches for our upcoming Electronic Instrument. She immediately recognized the Arduinos, of which I was kinda proud.

The switches were a disappointment though. Colorful and all, but unfortunately of the "latching" type, meaning a switch that stays down when you press it, and comes back up when you press it again. And that just won't do if you're planning to build a keyboard for a musical instrument, will it?

So, we started "modding" the switches be removing certain parts from inside. We had 15 switches to mod in total so there was some real work to do! You'd thing this would be tedious and boring for a 6-year old girl? Nope, not at all. Even the 3-year old helped the best she can. In the end, I was the only one (not counting the 3-year old in) unable to open the plastic casing of a switch without breaking it. 

So the 6-year old can now mod a switch without any adult help, and does it better than me... And here they are, all 15 switched, modded by willing child labor!

Then we did some design on how the instrument would look like.

Next up: woodwork. We need to build a casing for our thingie. And maybe we need to visit the local "recycling center" to scavenge some parts, including a little speaker element. The Hartke element might be a bit too heavy-duty for our use case, weighing 1 kg or so. You can see it in the picture too. Quite a monster, ain't she?

Friday, March 6, 2015

Soldering school

Today her older cousins were visiting. She organized a Soldering School where she explained how to solder and had them all do some basic soldering. Was fun.

Thursday, March 5, 2015

Solder On!

Yesterday she was sick and I got to spend the whole day at home with her. Guess what we did? Well, she slept and watched Netflix while I was working. For a while. But when she got her energy back, guess what she wanted to do. Solder. So we did some serious soldering. Behold the METAL HORSE!

And today, I asked her to do her violin homework. Guess what she wanted to do. Solder. So solder we did. She soldered a resistor on the perfboard perfectly!

Sunday, March 1, 2015

Lesson 66 - Solder Star

Yesterday she asked me if we could now build the magical electric instrument together. The one we discussed in Lesson 65. I said yes.

So we started by recapping on our previous work with electricity. She struggled with terms (voltage etc) but with some help, she was quickly able to construct a circuit that will light up a led with 3.3 volts from the Arduino. And she remembered that you cannot use 5 volts for that. 

Soon we were about to start connecting the speaker element to the board. Whoa! One of the wires soldered to the speaker had gone missing. We concluded that we're gonna have to solder it back. Now this speaker element is heavy-duty and has a magnet so powerful that when it gets stuck to a piece of metal, she can barely drag it free with all her might. Now imagine using a soldering iron on that. It'll do its best to draw the burning-hot iron to the speaker element. So we decided I'll do the soldering but she'll get to practice soldering after that. She helped me by keeping the wire in place with her steady little hands while I applied solder.

After fixing the speaker I let her do some free practice with the soldering iron, under my supervision, of course. She started by almost burning the power line of the soldering iron. After I showed her the burn-marks on the plastic cover, she took good care not to repeat that mistake again. Here are some of here works.

A stickman and a star that is. She wanted to keep on soldering but it was almost bedtime so we had to stop for now. Was fun! I think need a better soldering iron though. Mine's a 5 dollar one from the Internet.