I needed an idea that I could use to teach myself about using a relay with Microcontrollers and solve that age old problem: Switching between speakers and headphones on my PC without having to actually get up and mess around in the rats nest of wire’s behind it.
The solution: Use a 5v DPDT relay, a few 3.5mm stereo sockets and an Ethernet-capable Arduino to create a simple audio switch which would allow me to switch one audio source (my PC’s Soundcard in this case) to one of two outputs (headphones or speakers) via a web interface running on the Arduino from the comfort of my web browser.
This Alarm Clock Arduino hack , featured on hackaday, has to be one of the most innovative uses of an Arduino and Python I have seen! The maker, insingertech, has published full instructions on his hack here.
He goes into great detail on his build process and the diagrams (for the Relay Driver part of his circuit, especially) really help to explain things.
The only critisism I can think of here is that perhaps he should have used an Ethernet Shield for the network connectivity element of his project instead of a PC/Laptop.
Ok, so someone has already beaten me to it (and done a excellent job of it as well) with the whole web-based temperature monitoring thing, but anyway… Here’s Webthermo!
Webthermo, my follow-up to Ardthermo, is a small, web-enabled Python script which uses the CherryPy HTTP Python framework. It allows you to monitor temperature (in both Celsius and Fahrenheit units) over the Internet (using the port-fowarding facility of your Router), or on your own LAN via a web browser, your favorite RSS reader or a WAP-capable Mobile phone, using the same Arduino sketch and hardware setup as was used for Ardthermo.
It’s still in the early stages of development at the moment, so its still a bit rough around the edges but it works well enough. You can get a copy of the Python script, which also includes the Arduino sketch needed for the hardware side of things, from the Software page.
System Requirements and instructions on how to use Webthermo can be found below. Enjoy everyone!
Rich Davies has send in his Temperature measurement Sketch which uses an LM35 temperature sensor, as apposed to a thermistor. It can give readings in both Celsius and Fahrenheit, too. His Sketch code, which includes an ASCII diagram for connecting the LM35 to the Arduino, can be found below:
In this little project, the RSSI value (detected by a small python script) is used to control 3 LED’s on an Arduino. The LED’s are used to indicate the proximity (in terms of Far Away, Slightly Closer and Very Close) of a paired device relative to the PC running the script. The python script can also send a message to Twitter when the paired Bluetooth device is in close proximity to the PC.
The Arduino Sketch and companion Python script are both in the zip file rssitracker.zip which can be downloaded from the Software page.
After recently getting my hands on an Arduino Duemilanove, I came across this Sketch on Arduino Playground that allowed an Arduino to function as a temperature measuring device with the addition of a few cheap and easily obtainable components.
Deciding to take things a step further, I wrote a Python script to create a DIY temperature measuring device that could be used both locally, via the command line, as well as remotely, using a googlemail account to check the temperature of a room. You can grab a copy of this script, called “Ardthermo”, from the Software page.
This article should give all the info you need to know to build this little project for yourself and make use of the Ardthermo script. Enjoy.