Giving the Home a voice

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I have purchased an Amazon Echo Dot for my home automation project. But why?

As an Apple fanboy and iOS-developer this may sound crazy when Siri is already on my iPhone, Apple Watch and my Mac.

The simple answer is “hackability” or ease of use. The Amazon Echo is very easy and simple to develop new apps for (or Skills) compared to the Siri/HomeKit on iOS/macOS.

Skills is simply a webservice that handles requests from Amazon and responds with JSON data. You can spin your own server with e.g. Node.js or use AWS Lambda for a serverless application.

RF Research

One of the first items on my todo-list is finding a better way of handling all my wireless devices (data transmissions).

Currently I have build my own two receivers for weather sensors (temperature, humidity, rain and wind) and my mailbox notifier.

And the plan is to add many wireless devices once the system is able to do cross-communication between devices.

Luckily someone else is building and developing exactly this kind of receiver and it is called RFLink.

This let’s me send and receive on the open ISM Band (433/868 MHz in Europe) all using a simple serial protocol.

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New Years Resolution

Like Mark Zuckerberg did last year (Building Jarvis) I will dedicate the next year building my own Home Automation system.

The project will combine some of my existing systems and devices and a lot of both old and new. Because they all use different controls, protocols, frequencies, API’s and Apps it happens that I simply don’t use them all the time.

My goal is to have them all talk to each other (like IFTTT) and be controlled with one App or physical control panels around the house.

It’s not going to be an AI like Jarvis from Ironman but more like a hub for all devices for easy integration and use.

The current state of the project is research and purchasing components to start developing the base system. My old systems will be replaced first as a test.

Stay tuned…

PN532 + libnfc + mfoc with OSX

$ wget http://libnfc.googlecode.com/files/libnfc-1.7.0-rc7.tar.gz
$ tar xzvf libnfc-1.7.0-rc7.tar.gz
$ cd libnfc-1.7.0-rc7
$ ./configure --with-drivers=pn532_uart
$ vi utils/nfc-mfclassic.c

Comment out the following two lines

if (uiBlock == 0 && ! write_block_zero && ! magic2)
  continue;

Result

//if (uiBlock == 0 && ! write_block_zero && ! magic2)
//  continue;

$ vi libnfc/drivers/pn532_uart.c

Append 7 more 0x00 to allow wakeup to work correctly

const uint8_t pn532_wakeup_preamble[] = { 0x55, 0x55, 0x00, 0x00, 0x00 };

Result

const uint8_t pn532_wakeup_preamble[] = { 0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

$ make
$ sudo make install
$ sudo cp /usr/local/etc/nfc/devices.d/libnfc.conf.sample /usr/local/etc/nfc/devices.d/pn532_uart.conf

Connect the PN532 board using a serial to USB cable

$ ls -la /dev/tty.usbserial*
crw-rw-rw-  1 root  wheel   18,  12 May 13 20:16 /dev/tty.usbserial-FTDK0QLG

Notice the name of the usbserial TTY

$ sudo vi /usr/local/etc/nfc/devices.d/pn532_uart.conf

Change the conn string to the correct usbserial TTY name

name = "PN532 board via UART"
connstring = pn532_uart:/dev/tty.usbserial-FTDK0QLG

$ wget http://mfoc.googlecode.com/files/mfoc-0.10.5.tar.gz

$ tar xzvf mfoc-0.10.5.tar.gz

$ cd mfoc-0.10.5

$ ./configure LDFLAGS=-L/usr/local/lib PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
$ vi src/nfc-utils.c

Fix the following line by adding & before nt

str_nfc_target(&s, nt, verbose);

Result

str_nfc_target(&s, &nt, verbose);

$ make
$ sudo make install

You are now ready to use libnfc and the build in tools

$ nfc-list
$ nfc-poll

Node.js 0.8.9 on Rasberry Pi (Raspbian/Occidentalis)

How to install the latest (stable) version of node.js on a Raspberry Pi running Raspbian Wheezy or Occidentalis distros.

This is tested and both node and npm works without crashing with the “illegal instruction” error mesage.

Make sure to update your system and install the required build and developer tools.

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install git-core build-essential

Checkout Node.js source code.

$ cd ~
$ git clone https://github.com/joyent/node.git
$ cd node
$ git checkout v0.8.9 -b v0.8.9

Download and apply patches.

$ cd ~
$ curl -O https://github.com/joyent/node/commit/25c2940a08453ec206268f5e86cc520b06194d88.patch
$ curl -O https://github.com/joyent/node/commit/1d52968d1dbd04053356d62dc0804bcc68deed8a.patch
$ cd node
$ git apply --stat --apply ../25c2940a08453ec206268f5e86cc520b06194d88.patch
$ git apply --stat --apply ../1d52968d1dbd04053356d62dc0804bcc68deed8a.patch

Configure, make and install (NOTE: build time is very long 2-3 hours).

$ ./configure
$ make
$ sudo make install

You are now ready to start using node and npm!

Wireless weather station with Adafruit solar charger

I have a cheap $70 wireless weather station mounted on the roof and was tired of climbing up to change batteries.

So I decided to convert it to run on solar energy using a 6V / 250mA solar panel to charge a 4400mAh LiPoly battery.

It was relatively easy to replace the standard 2xAA batteries with a 3.7V LiPoly battery and solar charger from Adafruit.

Next step is to build an Arduino based receiver for the 434MHz radio signal and parse the weather data.

To be continued…