Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: cein on October 10, 2009, 12:03:33 AM

Title: help! 433Mhz RF ASK problem
Post by: cein on October 10, 2009, 12:03:33 AM
hi , i have been doing this supposedly easy thing for 2 days, without success.

RF Modules (Tx + Rx Pair) 433 Mhz ASK
http://www.robokitsworld.com/datasheets/TXC1.pdf (http://www.robokitsworld.com/datasheets/TXC1.pdf)
http://www.robokitsworld.com/datasheets/RXD1.pdf (http://www.robokitsworld.com/datasheets/RXD1.pdf)

so , i connected these two RF Modules (Tx + Rx Pair) 433 Mhz ASK to the encoder and decoder ht-640 and ht648l.

the problem is that the VT pin of ht-648l never goes high and no data is transfered.

so , i tried to connect directly from ht-640 to ht-648l and still nothing.
from the datasheet it says the operating voltage of these two is 2-12V.
normally i use 5V as the supply.
the weird part is that by accident, i discovered that ht-648l works on 3.5V only, just a slight increase and it shuts off. is the problem with this IC?
so, after it works on 3.5V , i add in the RF modules, and once again nothing happens.
this is the circuit.
http://www.rentron.com/PicBasic/8-bit-rf.gif (http://www.rentron.com/PicBasic/8-bit-rf.gif)
http://www.rentron.com/PicBasic/8-BIT-RF2.GIF (http://www.rentron.com/PicBasic/8-BIT-RF2.GIF)