# Home automation project

#### Penelope

Joined Sep 14, 2010
5
Hi
Im hoping to do a home authomation project for college a system that when the alarm goes off a person is contacted by phone, i'm having trouble finding info on whats involved in the circuitry and where to start really so any advice or useful links would be much appreciated

Thanks

#### Penelope

Joined Sep 14, 2010
5
I need to use the 8051 in the project

#### marshallf3

Joined Jul 26, 2010
2,358
First thing is you're going to need to learn the instruction set for the 803x/805x series of Intel CPUs as well as their family of interface devices.

#### Penelope

Joined Sep 14, 2010
5
The project is due in at easter next year, But i have to submit my idea by the 30th of this month.

I no in general what im doin up to the part of the alarm system is being scanned concstantly if thre is break a code is written for the 8051
Im not sure what to do from there to get a message or to ring a phone to alert them that the alarm as been set off.

#### marshallf3

Joined Jul 26, 2010
2,358
I wonder why they'd stick you with an 8051? No doubt a good chip, but quite antiquated. Even a Z80 or 6502 would have been better choices because more code examples still exist.

I would start out searching for an old book written about programming the Intel 803x/805x family of microcontroller ICs. You'll also need the interface chips and some static RAM to go with it as it solely has the raw data and address lines along with a tiny built in ROM.

If you're very, very lucky you might find a development board in the vintage computer parts section of ebay. Anything for an 8031, 8032, 8051, 8052 or 8052AH-BASIC would be quite a bit of help.

#### marshallf3

Joined Jul 26, 2010
2,358

#### Potato Pudding

Joined Jun 11, 2010
688
Those old designs are ground floor for Intel based systems. Intel chips have been the most iterative systems you could want. Intel are the CISC kings, just adding functions with every new design, so start at the beginnings and what worked then should still work now.

Starting out there is no need for anything more complicated than an 8051, but there is a good vertical learning path from there to anything more advanced.

#### marshallf3

Joined Jul 26, 2010
2,358
Those old designs are ground floor for Intel based systems. Intel chips have been the most iterative systems you could want. Intel are the CISC kings, just adding functions with every new design, so start at the beginnings and what worked then should still work now.

Starting out there is no need for anything more complicated than an 8051, but there is a good vertical learning path from there to anything more advanced.
They were certainly the workhorses of the day while the 6502s leaned towards games and the Z80s were somewhat inbetween, also found in the more complex games.

If you look hard enough (and have the ) you can still buy an 8052AH-BASIC chip. What a marvel to have a programming language built in.

#### Potato Pudding

Joined Jun 11, 2010
688
TO PENELOPE

There are PLL based devices at the low level if you are expected to build your own modem, but I think you will only need to find a modem chip or even peripheral modem then study it until you understand how to use it.

You will see your calling out problem is less difficult than it seems and probably among the most valuable interfacing projects you will get from your education.

I am looking at interfacing a lot since I/O is going to be my specialization in my Computer Electronics course.

If you have more questions it is worth it for me to help you with the research for this.

Would you use a cellular modem or a wired modem is one of the first questions to consider. A cellular modem you will need to look for an off the shelf device, or just hack an old cell phone. I would not suggest you go anywheres near attempting the GHz RF circuits involved in cellular transmitter/receivers.

In fact I would suggest you look for a land line modem first even if you need or want to build your own. Some reverse engineering will get you a good start and old modems should not be hard to find even if you are hoping for it to be given to you. At worst you should have to buy somebody a coffee in exchange for an old modem.

You can buy new USRobotics 56k modem cards for $15. No names sell for about$4.

Cable modems are another possibility but you wanted to dial out so that kind of excludes them.