Home Commander

Reading Temperature Sensor from STK500

Willem Visser — Thu, 19 Mar 2009 18:31:01 +0000

One of the plug-ins that is quite handy for home automation is temperate sensors. One can automatically start/stop air conditioners or sprinklers based on temperature, or simply use them as weather stations.

To get started, see the following great tutorial using the LM35DT temperature sensor: http://extremeelectronics.co.in/avr-tutorials/using-the-analog-to-digital-converter/

What I like about this sensor is it is linear, and very easy to use. No complicated curves or maths required to work out the temperature. And even better the sensor is very cheap and easily available.

If you have the STK500 like me, simply use Port A (that is where the ADC converter sits) and take pin 0, connect it to Vout on LM35, and connect Port A’s +Vs and GND to corresponding pins on LM35.

Use 104 capacitor across power pins of LM35DT.

That’s your wiring done. To display the temperate, my code outputs the temperature to my LCD connected to port B. See my LCD post to see how this is done.

Here is the project code:

Interfacing STK500 with LCD

Willem Visser — Thu, 19 Mar 2009 18:28:52 +0000

After a couple of attempts, I found the simplest way of interfacing your STK500 with an LCD is to use Peter Fleury’s routines (4-bit mode) and plugging your LCD directly to one of your ports on your board.

The only external component required is a 10K pot.

I obtained a LCD that has a HD44780 controller – there are numerous places where you can find the pin outs for it, here is one: http://www.jump.to/fleury

Welcome!

Willem Visser — Thu, 19 Mar 2009 09:20:30 +0000

Welcome to Home Commander.

HC is a project created by Willem Visser and David Graham to automate their own homes, with the idea of packaging the harware and software to enable the general less tech-savvy public to automate their own homes with a small budget.