wireless PIR motion sensor

[arod]

I am planning on building a wireless PIR motion sensor. My question is do I need to purchase encoders/decoders for the data transmission? I am planning on using the TX433 transmitter module, RX433C receiver module, and **broken link removed** as the PIR motion detector. Also, if you have any insight into any possible problems your replies are welcome.

 

[Nigel Goodwin]

It would certainly be best to either buy encoders, or program your own - as you really need a micro-controller to send the data, you may as well do the encoding in the software.

Perhaps an easier way would be to buy the Holtek remote control chips?, these are pre-programmed micros that do the coding and decoding for you, and are available for either radio modules or IR.

 

[arod]

Does it need to be encoded because of possible noise errors during the transmission? I've learned a few techniques for encoding and decoding, but this seems fairly simple already. The HT12-E is only like 1.50 and I'm sure the HT12-D is about the same. I've never really worked with wireless data transmission so I'm not sure if there are any other alternatives.

 

[Nigel Goodwin]

The Holtek chips you mentioned are designed for the job, they are also cheap!, it needs to be encoded so as to accurately identify the data. Most radio modules output random rubbish if the signal drops too low, Manchester coding is probably the post common way of sending radio data while avoiding the problems. There are PIC routines in one of my tutorials, but for your purposes the Holtek range are probably better?.