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Ben Martin: ESP8266 and a few pins

Mon, 2015-10-26 23:41
The new Arduino 1.6.x IDE makes it fairly simple to use the ESP8266 modules. I have been meaning to play around with a some open window detectors for a while now. I notice two dedicated GPIO pins on the ESP8266, which is one more than I really need. So I threw in an led which turns on when the window is open. Nothing like local, direct feedback that the device has detected the state of affairs. The reed switch is attached on an interrupt so as soon as the magnet gets too far away the light shines.





I will probably fold and make the interrupt set a flag so that the main loop can perform an http GET to tell the server as soon as it knows when a state has changed.



Probably the main annoying thing I've still got is that during boot it seems the state of both the gpio pins matters. So if the reed switch is closed when you first spply power then the esp goes into some stall state.



It will be interesting to see how easy OTA firmware updates are for the device.



Sridhar Dhanapalan: Twitter posts: 2015-10-19 to 2015-10-25

Mon, 2015-10-26 01:27

Hamish Taylor: The woeful state of communications in Australia’s capital city

Sun, 2015-10-25 21:27

For those who may not know, I recently moved from Melbourne, Victoria to Canberra, Australian Capital Territory (ACT) and am now living in a house in the inner north-west. Of course, being a geek, I wanted to get the internet connected as soon as possible! After such a smooth transition I’d expected some problems and this is where they all cropped up.

In Melbourne I had an Internode ADSL connection and before I moved I called them up to relocate this service. This, of course, relied on getting an active Telstra line at the new house. I knew it would take a bit of time to relocate the service, so in the interim I bought a Telstra wi-fi internet device. This is actually a ZTE MF30 and supports up to 5 connections via wi-fi, so I can get both my iPhone and laptop on at the same time. Quite simply, this device is brilliant at what it does and I couldn’t be happier with it.

So, at the moment I’m online via the Telstra device, which is just as well really, as I soon encounter communication issue number 1: Optus.

It appears that Optus have a woeful network in Canberra. I have an iPhone 3GS, which I know can only use 850MHz and 2100MHz 3G networks. Optus uses 900MHz and 2100MHz for their 3G, so the iPhone will only work in Optus 2100MHz coverage. In Melbourne I never had a problem getting on the internet at good speeds.

When I looked at the Optus overage maps for ACT and click on “3G Single band” (the 2100MHz network coverage), it shows the inner north-west being well covered. It really isn’t. Both from home and at work in Belconnen, I can barely get two bars of GSM phone signal. The connectivity is so bad that I can barely make phone calls and send SMSs. Occasionally, I get the “Searching…” message which tells me that it has completely lost GSM connectivity. This never happened in Melbourne, where I had 4-5 bars of signal pretty much all the time.

The 3G connection drops in and out so often that I have to be standing in exactly the right location to be able to access the internet on my iPhone. Even this afternoon in Kingston in the inner south, I wasn’t able to get onto the internet and post to Twitter. I had to use the Telstra device, which hasn’t missed a beat in any location for network connectivity, to establish a connection. This really isn’t good enough for the middle of Canberra. I am seriously considering calling Optus, lodging a complaint and trying to get out of my 2 year contract (which has another 10 months to run), so I can switch over to Telstra. I never thought I’d say this, but I actually want to use a Telstra service!!!

Communications issue number 2: TransACT. From what I can find out TransACT have a cable TV network which also has telephone and internet capabilities. When this network was established about a decade ago, it was revolutionary and competitive. Today the network has been expanded to support ADSL connections, but there is no ability to get a naked service as all connections require an active phone service. Additionally, as a quick look at some of the internet connectivity plans show, after factoring in the required phone service, it is a costly service for below average download allowances.

When I moved into the house, the process of relocating the Internode ADSL service from Melbourne to Canberra triggered a visit from a Telstra technician. However, he wasn’t able to find a physical Telstra line into the house. Being an older suburb of Canberra, this house will have a Telstra cable. Or rather will have had as apparently it is not unknown for TransACT installers to cut the Telstra cables out as “You won’t need THAT anymore!”

So now I have to pay for a new cable to be installed from the house to the “Telstra network boundary” (presumably the street or nearest light pole where it can be connected to Telstra’s infrastructure). Then we have to pay again for a new Telstra connection at a cost of $299. Considering that if the Telstra cable had been left in place, the connection cost would be $55, this is turning into quite an expensive proposition just to get a naked DSL service.

All in all I am not impressed with the state of communications in Australia’s capital city, Canberra. All I can say is please, please, please bring on the National Broadband Network (NBN)!

 

 

Colin Charles: Mark Callaghan at the Korean MySQL Power User Group

Sun, 2015-10-25 14:25

The Korean MySQL Power User Group gets a special guest speaker next weekend (Oct 31 2015 – 4pm – 4:33’s offices in Gangnam — nearest train stop is Samseong station, Line 2 — post requires Cafe Naver login) — Mark Callaghan (Small Datum, @markcallaghan, and formerly High Availability MySQL). I’ve been to many of their meetups, and I think this is a great opportunity for many DBAs to learn more about how Mark helps make MySQL and MongoDB better for users at Facebook. I’m sure he’ll also talk about RocksDB.

After that, as usual, there will be a DBA Dinner. This time the tab gets picked up by OSS Korea. See you next Saturday — Halloween in Seoul will have added spice!

Colin Charles: MySQL NL Community Meetup with MariaDB speakers summary

Sat, 2015-10-24 22:25

Last week we had the MySQL Meetup with MariaDB Developers in Amsterdam, which went on easily for about 3.5 hours. Thanks to all for listening (these were lightning talks, not with a strict 5 minute clock with Q&A thrown in), and Daniël van Eeden for organising this at the eBay offices (whom kindly provided pizza, beer and soft drinks as well). We had many talks, and I’ve managed to put up most of the slides into a Google Drive folder, so feel free to access the bucket.

  1. How is the MariaDB sausage made? by Rasmus Johansson covers how MariaDB Server gets made from an engineering standpoint
  2. An inside look at the MariaDB restaurant by Daniel Bartholomew covers how MariaDB Server gets released
  3. ANALYZE for statements by Sergei Petrunia
  4. Data at Rest Encryption in MariaDB 10.1 by Sergei Golubchik (HTML presentation so will prompt a download for you to view in the browser)
  5. Cool MariaDB Plugins by Colin Charles
  6. Passwordless login with unix auth_socket by Otto Kekäläinen
  7. InnoDB in MariaDB 10.1 by Jan Lindström
  8. PCRE Regular Expressions in MariaDB by Alexander Barkov
  9. MaxScale by Massimiliano Pinto
  10. Overview of failover handling in the MariaDB Java Connector by Diego Dupin
  11. Profile Guided Optimization by Axel Schwenke
  12. MariaDB Server in Docker by Kolbe Kegel
  13. Systemd by Dan Black (there were no slides, and the work was being pushed into 10.1, so the crowd got to see svoj come up with his laptop, and Dan made the commit by hitting the Enter key. IIRC, the commit was 20c2ae39db3dd0ec4c337a9b0bd2bf4481b61e49)
  14. Engine Independent Table Statistics including Histograms by Sergei Petrunia

Georg Richter had prepared a presentation but decided not to give it, since we already had quite a lot of talks and discussion throughout the sessions. If you’re interested in MariaDB Connectors, the presentation is worth a read.

Thanks again to Daniël van Eeden and Jean-François Gagné whom really helped get this stuff going.

P/S: for some pictures, I live tweeted them:

Standing room only for @mysql NL meetup group with #mariadb developers talking today @mariadb pic.twitter.com/Hwnu1HxrDY

— Colin Charles (@bytebot) October 12, 2015

The @MySQL NL meetup with #mariadb folk – yes it's a lot of learning today @mariadb pic.twitter.com/UD9gWnly64

— Colin Charles (@bytebot) October 12, 2015

When the questions get serious, we see @mariadb @montywi talk too — @mysql NL meetup #mariadb pic.twitter.com/Qv4k84XZ0S

— Colin Charles (@bytebot) October 12, 2015