Audio

Upgrading a vintage tube radio to support Bluetooth A2DP

My old tube radio has a gramophone input that acts like an auxiliary in. There I injected the audio output of a cheap 9$ bluetooth A2DP audio receiver from china (dealextreme) and connected a standard 5V power supply unit which is switched on together with the radio. This way I got my personal handmade bluetooth speaker. I really like the warm sound of these old radios and feeding it with a modern cell phone feels just super cool.

Attention: Be careful if you also want to upgrade an old radio! Most of them run directly on 230V. Be sure you know what you do!

This project also shows some sort of implicit critics against the just-so-common planned obsolescence. Do you think the stereo you bought just a couple of months ago will still work in 50 years? I guess not.

Video

Botman – my homegrown home automater

My home automator – nicknamed “Botman” – has some nice features:

  • Indoor data: shows the current room temperature, humidity and barometric pressure on the display (1st row)
  • Outdoor weather: regularly requests current weather conditions from a weather API and displays them on the display (2nd row) and moves the servo arm to what we normally call the “weather icon”
  • Public transportation info: current departure times of public transport options around my flat are pulled from the web allowing me to better schedule when I have to leave my flat.
  • Archive indoor conditions: temperature, humidity and barometric pressure are regularly sent to a Google Spreadsheet to archive and visualize the data over time.
  • Android App: allows me to check the current data and lets me switch my remote controlled outlets on and off.

Technical overview:

  • Arduino Ethernet acting as a web server but also as web client when it pulls data from APIs.
  • I2C Display (lcm1602)
  • Laser cut dashboard (thanks to metalab.at)
  • Servo arm showing current weather forecast
  • Wooden self built enclosure
  • Temperature, barometric pressure, humidity sensor (BMP085, DHT11)
  • 433MHz wireless sender for remotely controlled outlets

As you might know the Arduino does not have a lot of memory. So parsing current JSON APIs might be a big pain in the *** or would simply not be possible – e.g. due to unsupported https connections. That is why I have installed a separate Google App Engine instance which does all the hard work and only returns the small data chunks I really need on the Arduino.

Of course security is always a big issue when it comes to home automation. All the data is transported on an unencrypted standard http connection. At the moment I can cope with this imperfect approach.

Codebender:

  • This is the first project I moved to the Arduino browser based IDE  codebender. It really helps me to save plenty of time as I do not have the hassles of setting up the Arduino IDE with all the proper libraries. Perfect for people who tend to experiment a lot or switch their dev. machine too often :)

Todos:

  • make a better hand for the pointer of the weather icon
  • prepared to control door opener of house
  • prepared to add Ir diode to control any device with an Ir remote