Sunday, May 21, 2017

Tokyo National Museum

I've been living near Tokyo for a while now, but for some reason I had never visited the Tokyo National Museum in Ueno. But I'm glad that I did it a couple of weeks ago.

The museum contains a great collection of historical objects including katanas (Japanese swords), ceramics, and paintings (I love the ukiyo-e collection, specially those paintings where yamauba and Kintarō appear). The entrance fee is quite reasonable if you skip the temporary exhibition.

Futsal in Kanagawa

One of my passions since I was young is playing futsal. What I like the most about futsal is all the "speed thinking" involved. Some people associate futsal with physical strength, but in my opinion thinking speed and accuracy when passing the ball are the essence of this game.

In Japan, futsal is often played outdoors and on artificial grass. There are many futsal stadiums that allow individual participation (個人参加) where you just go, pay for the time and join other futsal enthusiasts. I usually play once or twice a month. Recently I played with some good old friends that I used to play with when I was in Nagoya University. It was nice to meet them. My favourite place to play futsal in Kanagawa is Futsal Point in Suzuki-chou (a 20 min walk from Kawasaki station).

Reading picture books for children

During the last year, I have been invited several times to participate in a group of volunteers that read picture books for children in different languages. This kind of groups, called dantai in Japanese (団体), are very common in Japan. If you want to participate in one you just need to ask at your closest cultural/community centre (search for 文化センター,市民センター,コミュニティセンター, or 区民センター).

One of the books that we read very often is "The very hungry caterpillar". The title is translated as "La oruga muy hambrienta" in Spanish and "Harapeko aomushi" in Japanese. We also read other books including my own.

A month ago I went to see an exhibition of the author of "The very hungry caterpillar", Eric Carle, at the Setagaya art museum. Eric Carle's paintings were really interesting from the technical side as well. Many of them were a collage of pieces of semi-transparent textured paper painted with acrylic colours.

Saturday, May 20, 2017

OSC 2017 Spring

The Japanese Open Source Conference, usually known by its initials OSC in Japan, is a great event for open source enthusiasts. It is celebrated in different japanese cities and regions throughout the year such as Tokyo, Hamanako, Osaka, Hiroshima, Fukuoka, Kyoto, Nagoya, and many more. Here is their official OSC Twitter account.

Although I have attended the conference many times I had only reported once in 2013. This time I attended Tokyo OSC 2017 Spring which was held at Meisei University, a private University that has great rooms with multiple screens.

During the conference I made a short introduction to Fuego, an open source test framework that I'm contributing to recently. You can find the slides here. This wasn't my first presentation in OSC but it was the first one I did as part of my job. You can also find the videos and slides of other presentations given during the conference here. I was very interested in the Lagopus project, which supports DPDK (a cool framework for zero-copy network applications); the Vuls vulnerability scanner; and also Volumio, a Hi-Fi digital music Linux distro.

Although I normally use the Tama Dōbutsuen Station which is right in front of a zoo (Dōbutsuen means zoo), about 15 min walk to the OSC building, most people prefer to use the Chuo Daigaku-Meisei Daigaku Station on the Tama Monorail. Here is a picture of it on my way back to the station.

Conclusions: it's always fun to attend the OSC and learn about new trends, software and make new friends. Also I think it is especially fun if you make your own presentation.

Wednesday, May 17, 2017

Assembling a dsPIC-based DIY oscilloscope

In August 2015, I attended a Tokyo Hackerspace event called building a DIY oscilloscope. However, it wasn't until December 2016 that I finally assembled and tested it!.

During the event, we received a kit from Carl Blaksley that was based on an original design by Ajoy Raman. The hardware is quite simple and consists of 3 main components: the analogue interface, the processor and the USB interface. The analogue interface includes a few RC filters and 2 programmable gain amplifiers (SPI protocol) MCP6S22 (one for each channel). The amplified signal is then sampled by the processor, a dsPIC30F2020 which contains a 10-bit 2 Msps ADC (shared among the channels enabled). Finally, the USB interface is handled by the famous USB-serial FT232RL chip. Carl was nice and sent me the Kicad design files of the board. The assembly went quite smoothly but as always I had to debug a hardware problem that ended up being caused by my USB (a cross USB cable was needed).

The software was written in python and worked fine on Ubuntu 16.04 (there is also a visual basic version for Windows). To test it, I installed this amazing Android function generator application and connected it to the oscilloscope through a 100yen (sold at Seria) headphones stereo amplifier.