2019-09-04 (Wednesday)

Today, I learned that:

There is finally something really BIG happening in the world of serial communication between electronic devices. Last Thursday, 2019-08-29, was officialized the release of a new version of the popular USB interface, version 4, USB4 to be short, with a maximum data rate of 40 Gbit/s. See also reference #1 below.

From RS-232 to USB4

So, what is so special with this version then? Well, it seems that we now, almost 60 years after the RS-232 serial protocol was introduced, have returned to only one standard, regardless of the brand of the device.

It all started in 1960, when the American industry organisation EIA (Electronic Industries Association) introduced the RS-232 standard, initially to be used between electromechanical teletypewriters as DTEs (data terminal equipment) and modems as DCEs (data circuit-terminating/communication equipment). According to today’s standards, it was extremely slow, maximum 20 kbits/s.

RS-232 had some successors, such as RS-422 and RS-485, where both the speed and maximum cable length had been improved. For example, RS-422 is specified for a maximum bitrate of 10 Mbits/s and a maximum cable length of 1500 m.

We now jump to the 1990s, when the emerging personal computer (PC) industry found that maintaining the RS-232 communication was not feasible. There were then started two different initiatives to make communication between a PC and its peripherals much easier and faster. On January 1, 1996, was released the first version of the universal serial bus (USB). It had been developed by a consortium of companies such as Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. The data rate of USB 1.0 was 12 Mbits/s, which was improved to 480 Mbits/s with version 2.0 in 2001 and 5 Gbits/s through USB 3.0 in 2014, 10 Gbits/s by USB 3.1 in 2014, and 20 Gbits/s specified by USB 3.2 in 2017.

As you can see above, Apple did not participate in the USB consortium. Instead they had decided to develop their own communication interface, and attracted other companies such as Sony, Panasonic, Philips, LG, Toshiba, Hitachi, Canon, Thomson, and Texas Instruments. This group developed what came to be known as FireWire 400, aka standard IEEE 1394-1995. The data rate of this version was a maximum of 400 Mbits/s in half-duplex mode. It was followed by FireWire 800, which reached the speed of its name in 2006. However, Steve Jobs declared that FireWire was dead in 2008 when many camcorders were still using USB 2.0, instead of the faster FireWire.

Intel, which as you saw before already was a leading force in the USB consortium, now started to develop a new hardware interface together with Apple. It was dubbed Thunderbolt, and the first version appeared on MacBook Pro computers in 2011. Sony also used it in a Vaio line of notebooks in 2011. It was later followed by Thunderbolt 2 in 2013, with a maximum data rate of 20 Gbits/s.

And then, in 2016, Thunderbolt 3 was introduced, and as of now we can see that both standards are coming closer to each other, because they share the same USB-C connector. Intel decided in April 2019 to release the Thunderbolt without charging royalties from the companies who would use it, and that was the signal to finally use Thunderbolt 3 as a starting point for the specification of USB 4.

Will this mean that there is now unanimity in the electronics industry to start using only USB 4? Let us hope so, and that we will see the concrete result starting to appear in about a year or so.

There is much more to be said about this interesting topic of data communication, please see references # 2 through 7 below for details.

If you can’t beat them, join them!

A big problem in the crazy traffic in major cities around the world is of course that so many different categories of people on the move need to share the same physical space. Maybe the most troublesome is when motorbikes try to squeeze their way through in the small corridors between the cars. In 1997, when the most recent Brazilian Code for traffic was published, it permitted that they could do so, contrary to safety measures. And as a consequence, every day quite a few of those bikers are involved in severe accidents, even deaths.

However, one of the ways to mitigate somewhat this conflict was created in 2013 in São Paulo. You can see it in today’s header photo, taken downtown on 2019-08-09 at Avenida Ipiranga. It shows that motorbikers and other bikers, as well, have a privileged zone in front of the cars, when they need to stop for a red light. That way, when the light turns into green, they can speed away without needing to negotiate space with the car drivers. This method is called “Frente segura”, which means ‘Safe front’. More about it can be seen in reference #8 below (in Portuguese).

That’s what I learned in school !

Refs.:

1: USB4 Specification merges Thunderbolt 3 and USB with transfer speeds up to 40 Gb/s

2: RS-232

3: RS-422

4: RS-485

5: USB

6: IEEE 1394

7: Thunderbolt

8: Frente segura

*: What did you learn in school today ?

Advertisements

2016-09-03 (Saturday)

Today, I learned that:

Exactly 49 years ago, 1967-09-03, Sweden changed the rules for driving, from the left-hand side of the road to the right-hand side. It had already been the subject of a referendum held in 1955, where 82,9 % of all votes were in favour of status quo, i.e. continue to drive of the left-hand side. But the referendum was not decisive, only consultative, and external pressure of unifying the “right side” for driving eventually had the Swedish parliament decide on a change.

Already one year before the switch would take place, the actions started to teach the population how they should behave while driving after “H-dagen” (‘H Day’, where H stands for “höger”, the Swedish word for ‘right’). And thus the switch itself went very smoothly, no major accidents. Even though I was too young to have a driver’s license myself, I still remember waking up in the morning and seeing how the cars started to move from the left side of the road to the right one at 05:00 in the morning, and then at 06:00 was finally given the “go” signal. Below are some interesting images from the switch, complete articles can be found in references # 1 and 2 below.

Dagen H

Six illustrations related to the Swedish left-to-right switch. In the upper row, from left to right: – Propaganda on a Stockholm bus appealing to vote NO in the referendum in 1955; – The people managing the switch showing the sign with a big H, which was placed in thousands of places in Swedish roads; – Kungsgatan in Stockholm during the switch. In the lower row, from left to right: – The official symbol of the switch; – Gloves to remind the driver to drive on the RIGHT side; – This road sign ceased to exist at the switch, it meant that the earlier limited velocity now was invalid, thus imposing no formal limits to the velocity, but after the switch there was no more free velocity on Swedish highways .

And so you may ask, what does the following photo have in common with traffic? Well, it was taken in an EU country that still insists on driving on the left side of the road. No, it is not Britain, but one of its former colonies, Malta, located in the Mediterranean sea. My friend Rikke just returned from a marvellous vacation there, and besides this beautiful photo, she has promised us to deliver more like that one. We very much look forward to it, in the meantime here are our warmest thanks to her!

Malta2

A tempting scenery from Pembroke, Malta. It is located 10 km North of Valeta, Malta’s capital. Photo taken by Rikke Wilhelmsen on 2016-08-22.

… That’s what I learned in school !

Refs.:

1: Day H

2: Högertrafikomläggningen

+: What did you learn in school today ?

2016-03-26 (Saturday)

Today, I learned that:

We have arrived at the Easter weekend and in most countries where Easter is celebrated, it is normally Easter Sunday which attracts the main interest culinarywise. Sweden is an exception, there it is Easter Eve, Saturday, that has that attribute.

So I would like to contribute with a marvellous dessert to break the normal sweets tradition. Avocado for most people is known for its use in appetizers, e.g. filling it with prawns, caviar, etc., and of course as a guacamole dip for the tortillas or nachos. But in Brazil, we like to eat the avocado sweet, mixing its pulp with sugar and water / milk, to form a delicious cream. See the photo and reference #1 below.

Creme de abacate

Avocado cream is extremely simple to make, and yet it is so tasty. Just divide the fruit in two halves, scrape out the pulp and place it in a blender. Add some sugar and a liquid, either water or milk. Dose and blend well to desired consistency. If you use water, then some lime will give the cream a delightful contrast. But do not add lime if you are using milk, they do not go well together chemically.

This morning, I heard some distressing news from the local news program of SR Sjuhärad. It was reported that the new EU regulations about traffic safety does not oblige the car driver to have his/her tail lights lit when out driving in the fog. To me, and so many others, that seems like a dangerous degradation of the safety rules. Let us hope that the human drivers have more wit than the EU legislators and leave the lights on. See also reference #2 below.

In two earliers posts, 2016-03-10 and 2016-03-12, I reported about the outcome of the first three games of Go in a best of five series challenge between the AlphaGo computer and the Korean master Lee Sedol. Here comes the final report, in which Lee won his first game and AlphaGo won one more. So the challenge victory went to AlphaGo with a 4-1 match record.

Go45

The results of games 4 and 5 in the challenge series between AlphaGo and Lee Sedol show how the two opponents won one game each. The final result of the 5-game series is thus 4-1 to AlphaGo

… That’s what I learned in school !

Refs.:

1: Avocado

2: Släckta bakljus ger sämre säkerhet i dimma

3: AlphaGo’s ultimate challenge: a five-game match against the legendary Lee Sedol

+: What did you learn in school today ?