View Full Version : RF Decoding problem

Gary D.
01-16-2006, 06:35 AM
Hello all,

I have a bit of a decoding problem here. I have a linx 5 button 433Mhz keyfob transmitter and a Linx RXM-433-LR long range receiver. both were purchased from Linx directly. the keyfob has 5 buttons and a Holtek HT640 Encoder chip. Basically i am trying to read the five button values from the Keyfob transmitter without tying up five I/O lines of the stamp (i.e. trying not to use a decoder chip). My BS2 is connected directly to the Data output from the receiver. when i push buttons i get the same value for all the buttons. could i be reading the data wrong?

how do i decode the values being sent from the Holtek Chip?

thanks for any help.

Receiver Documentation (http://linxtechnologies.com/documents/RXM-xxx-LR_Manual.pdf)
Keyfob Data Guide (http://linxtechnologies.com/documents/cmd-key_manual.pdf)

Jon Williams
01-16-2006, 06:44 AM
You might need to do some empirical testing if you can't find the information in the Holtek docs. Try connecting the serial output you want to read to a scope and have a look at the packet output when you press the different buttons on the remote.

Jon Williams
Applications Engineer, Parallax