Jennifer got a groupon for us to go try K1 Speed Indoor Go Kart Racing in Santa Clara. Turns out it's a stone's throw from where Speedring used to be before it closed.
What's special about this place is that all the karts are electric.
So, what I thought about the place:
unfortunately, they use lead acid batteries, so they don't have the power to weight ratio I was hoping for. They were fast enough, but not as fast as other indoors gas karts I've driven.
the lack of noise is actually not bad, and the lack of fumes is good :)
they have 3 rows of cars and 2 charge while the 3rd one is used. That's not so bad.
the track layout is a bit basic (easy-ish), but eh, it's still fun enough to drive.
the kart max speed is remotely controlled. This is used to force you to do a slow lap and come back in slowly or stop everyone to walking pace if there was an accident. It's a bit spooky but I guess that makes sense.
karts have a reverse gear, that's cool since they help you get out of a tight spot without external help.
All in all it was different but still fun :)
Jennifer is still lacking a bit of the aggressive spirit necessary to push people around who are blocking you, and making a spot where there isn't one, but her fastest clean lap wasn't that much slower than mine. She did well :)
TL;DR: Get code here: https://github.com/marcmerlin/aiko_pebble_v2
Note, you will need the LiquidCrystal_SR_LCD3 driver from the NewLiquidCrytal Library.
You will also need the Aiko Library: https://github.com/geekscape/aiko_arduino .
Pebble v2 requires at least the IDE 0.23 (untested) but 1.0 or better is recommended. The code is of course arduino 1.0 compatible.
At the LCA 2012 Arduino Miniconf, we got to build a new toy, a Freetronics Pebble v2 (schematics here). This was a refresh of the Pebble V1 (schematics here) which was the target of the very first arduino miniconf I missed in 2010.
This new Pebble had even more hardware to program against and was a much more compact design due to the use of a bunch of SMT parts (actually there are 2 arduinos on the board, one is dedicated to usb/serial communications, removing the need for an ftdi chip).
Like good hacking projects and conferences, the design and software were improved until the last minute, and Andy worked all night before the conf to get us his demo code (along with bits from Luke and others).
Andy wrote the very cool aiko event handler for arduino. You give it a list of callback functions and it'll do its best to call them on the interval you gave it (interval in milliseconds). For arduino folks, with Aiko, code looks like this:
void setup(void) {
Serial.begin(DEFAULT_BAUD_RATE);
// Call LCD init early so that others can write to it.
lcdInitialize();
Events.addHandler(clockHandler, 1000);
Events.addHandler(lightHandler, 1000); // Aim for 250 ms
Events.addHandler(rotaryEncoderHandler, 100);
Events.addHandler(serialHandler, 30); // Sufficient for 38,400 baud
Events.addHandler(temperatureHandler, 1000); // Aim for 250 ms
Events.addHandler(touchPanelHandler, 250); // Aim for 50 ms
Events.addHandler(rgbLedFadeHandler, 10); // Can run slower.
// Call LCD last so that it can display variables that just changed.
Events.addHandler(lcdHandler, 1000); // Aim for 100 ms
}
void loop(void) {
Events.loop();
}
So Andy got us working code to test our hardware, but of course it wasn't fully optimized (hell, code never is). So, that gave me a chance to do some arduino programming to see what could be improved. It was a good learning experience.
After a bunch of work, here is what I was able to do:
I happened to have RGB LED demo code I had taken a while to write over Xmas (nice transitions that I went through the trouble of writing so they would work with an Aiko event handler), so I did a bit more hacking to refine the code and plugged it in.
The rotary button was being polled every millisecond to catch which was it was turning. First I figured that every 5ms was probably enough, but thanks to sample code from Brett Downing, I was able to write a handler using hardware interrupts on input pin state changes (something I knew nothing about, so it was a good learning experience).
Then this brings us to the LCD handler. I had some grand view of writing a popup menu that would let you configure the code at runtime, but that meant a lot of LCD code. I knew arduino had a nice LiquidCrystal library, but it did not work with the shift register setup in the Pebbles. Long story short, I wrote a plugin for the Pebble/LCD3Wires shift register setup in the Pebble. This demo requires this new library (LiquidCrystal_SR_LCD3) to do its work.
The 4th line shows the color that the RGB LED is changing towards
LED 6 means that the color change delay factor is 6 (lower means faster color changing)
3 in LED 6/3 is by how much the color brightness is reduced (clips the color values so that they arne't too bright, mostly useful in dark rooms or when taking pictures).
LCD 80 is the analog PWM value for the LCD backlight (higher is brighter).
A few custom characters are displayed to show use of the custom character support brought by LiquidCrystal_SR_LCD3
TL;DR: Get code here.
All the code is arduino 1.0 compatible
After coming back from the Arduino Miniconf at Linux.conf.au, I ended up with a freshly soldered freetronics pebble v2.
Like the Pebble V1 (schematics here), it uses MC14094 8 bit shift register to drive the LCD using only 3 wires instead of 6 or more.
The Pebble designers thankfully used the same shift register wiring than shown on the LCD3wire page on arduino playground. However, the code that came with it only had limited functionality for talking to the LCD, and the code on the LCD3wires page is also limited in functionality (on top of being incompatible with arduino 1.0).
So, I ended up finding Francisco Malpartida's cool work on virtualizing the stock arduino LiquidCrystal library (very featureful and optimized timings). In turn, Ragnar used that codebase to design his own shift register library for 2 or 3 wires.
Ragnar's wiring and code is somewhat complex because it exploits some interesting hacks:
it is designed to work with cheaper non latching shift registers.
it can be made to work with just 2 wires instead of 3 for non latching shift registers.
because of the design, the code is less obvious and exploits some tricks, but it sure works :)
his code can work for latching shift registers, but I do not recommend using the more complicated wiring and code if you can afford 3 wires and a shift register. Just use the LCD3Wires wiring and the code from this page.
In other words, if you have a non latching shift register, use his code and wiring. If you have a latching shift register, you should use the code from this page and the more widespread LCD3Wires wiring.
So, where does this bring us?
I used Malpartida and Ragnar's work to make an LCD3Wire hardware driver for the NewLiquidCrystal Library. This brings full library support to the pebbles as well as other folks who use the reference wiring from LCD3wires.
I called the new library NewLiquidCrystal in the hopes that it will become the new de facto library in standard arduino one day. My code is here: https://github.com/marcmerlin/NewLiquidCrystal and includes the new LiquidCrystal_SR_LCD3 driver I wrote. To be clear, all the code came from Francisco Malpartida's work, I built on top of it to write my LiquidCrystal_SR_LCD3.cpp driver for LCD3Wires compatible hardware.
I also wrote an extended LiquidCrystal Demo which should work on all liquidcrystal supported devices (baring the character count).
Here is a demo of my popup menu code that works with a rotary button (cursor showing what is currently selected if you click on it)
I'm now working with Francisco to get my code included in his tree, and if we're lucky that code may eventually get included in the standard arduino libraries as a faster and more flexible LiquidCrystal replacement.
One new year, one new Linux.conf.au conference. This time I was off to Ballarat for LCA 2012.
As a first time ever, I was lucky enough to get a 1st class seat for a flight to Australia (actually I'd have been happy enough with business, but that was not available). I still don't think it's worth the 'list price', but considering the quite reduced price I was able to get it for, it almost felt ok :)
I setup a little office I could work in :)
So what is there to say about Ballarat. It's a former mining town. The town itself can be visited in an hour or so (count a day to see the nearby attractions). All in all, definitely not something you'd fly from abroad to go visit, but since Linux.conf.au, my favourite conference, was there, so so was I :)
Downtown had a few old buildings that were kind of nice:
Ballarat's birds were loud but pretty :)
but the town was pretty sad. On a saturday afternoons, shops in their main 'mall' had closed by 16:00. I remember walking in front of a sushi restaurant that was supposed to close at 18:00 (on a saturday again), and they were closing early at 16:30 while giving me a 'sorry' look. In the end, there were only a very few places that were open for dinner.
Oh well, it was not a big town, I just had to know that :)
They had an old observatory with vintage telescopes, we went there one evening to do a bit of stargazing
After the conference, I went to visit what seemed fun to visit. Bird World was a grandma and grandpa 'shop'. it could have been a lot of fun, but unfortunately their free flight cage net was broken, so they had to put all their great parrots in cages. It was a bit sad since I could tell some were very friendly and would have loved to interact with me.
this one was so friendly and definitely wanted to come say hi
Next, I went to Sovereign Hill. This is actually the highlight of this town, a recreation of what used to be this old gold mining town. They have shops and blacksmiths like 150 years ago, and people dressed in the style of the day. Kids can pan for gold in the river.
Someone also showed how they make gold bars:
They had authentic machinery using steam power:
They then had a night show that was a recreation of the mini insurrection that happened there against the British taxation. Too bad they got squelched by the British and never fought back after that.
After a ncie visit to Sovereign Hill, I went to see the local Ballarat Wildlife Park. What can I say, I'm a sucker for Autralian wildlife parks (which I much prefer to zoos). It's always fun to be able to pet a few unusual animals like a wombat, and hand feed kangaroos or wallabies.
While I didn't expect too much, at the same time I've actually been pleasantly surprised by such parks in the smaller towns, and that turned out to be true there too.
Their crocodile feeding was particularly impressive, their kangaroos quite friendly, and petting wombats was cool :)
this was a very cool layed back kangaroo, nice claws too ;)
food, for me? :)
kangaroo was friends with wombat :)
food comma :)
those things peck hard when you feed them, they don't know any better :)
The crocodile feeding was quite impressive:
this guy really had balls, even by Australian standards :)
I hope he gets paid enough for this :)
While it was a small town, the places to visit still made for a fun day.
So this year LCA 2012 was in Ballarat. As per my Ballarat post. While it wasn't the most exciting city in Australia, I just spent more time at the conference itself and with my confernece buddies.
Dinner with friends
The first day, we had the Arduino 2012 miniconf where we built the new Pebble v2:
Jon Oxner, making sure one of the Pebble V2 was built correctly
This gave me something to play with during the conference. I spent most of my free time hacking on my new Pebblev2 board after the fact and ended up writing a new lcd3wire library and a much improved Pebble v2 Aiko Demo Code.
At the end of the conf, I went to the Hackerfest, where I got to write the rest of my code for my Pebble v2 :)
Andy Gelme and I, riding in style, to the hackerfest :)
Yeah, it works (mostly!) :)
John brought some samples from freetronix for us to play with, drool over, or buy and bring home :)
But back to LCA 2012. They had some great keynotes (they were covered on http://lwn.net/). The keynotes are on youtube.
The talks themselves, there were very some good ones. You cand find all the videos on the LCA 2012 youtube channel:
Two of the speakers sent one of their probes to near-space with a helium baloon after their talk:
And to finish a few random pictures of dinners and evenings:
That T-shirt is so full of win :)
Mikal came at the end of the conference to tell us about next year, and he's going to be the poor sob who's going to run it next year. Beat of luck Mikal :)
And just like that, the conf was over:
As always, LCA was a very well run conference, and despite the choice of a location that was very inconvenient (the uni itself being too far from whatever already limited city center was available in Ballarat), I had a great time again. In the end, it's still about the people, the conference, and the speakers.
On my flight back from Paris, we had an interesting flight path that was just at the edge of the sun coverage of the earth. As a result we skirted the line of sunrise for about 30mn over very northern canada, and it yielded some great pictures, even if they were a bit hard to catch through a plane window:
Jennifer had to go home early due to work (which then became a small surgical procedure), but I stayed in Paris and worked at the office there so that I could be there for our yearly Dutch family gathering. Most people made it, it was nice to catch up:
The next morning, we stayed at the same bed and breakfast we have been staying at these last years:
I swear, this picture looks just like the same than last years :)
for old times' sakes I went to catch one of her farm chicken
Like last year, I worked out of the Paris office for the first week of January (waiting to go to Holland for the following weekend). Unfortunately the new Paris office, while announced, wasn't quite open for business yet: we had some people there, but the building is still being worked on heavily, so most people have not moved yet.
I went for a quick visit and took a few pictures:
After that I spent the rest of the time in the 'old' office:
Since we were obviously starving by now with the very limited food we had been able to get so far :), François and Martine had us for New Year's lunch.
