Can I control the receiver/transmitter with a 16F84A and 12F629 respectively? All diagrams I can find use the HT12E and HT12D to endcode/decode.
When I read the PDF above that describes the transmitting/receiving modules, I was left with many questions.
Basically, how do these things work? Let me explain. When I pull transmitter low, does the digital data out pin of the receiver go low as well? Isn’t that the point? I thought it would be simple to test this by making a LED 4x7 display on the receiving end say “----” when the pin was low and “SGnL” when it was high. Then I made the transmitting end simply put negative voltage on the data-in pin and take it off, sort of like blinking a LED, only blinking the negative voltage on the transmitting pin about every second or so.
Well, the problem is this: If the transmitter is off, the receiver will show SGnL for about a second, and then it will light up both SGnL and ---- at the same time (jumping back and forth so quickly that they both appear lit). This is very strange, as I would expect the pin to be low if there is no transmitter.
Hooking up the tranmitter, it appears that the correct result is show on the display only for maybe a tenth of a second after the transistion. After that, both ---- and SGnL appear. This leads me to believe that if nothing is being transmitted, the pin somehow oscillated back adn forth between 0 and 1, and during transition, it is 0 or 1 for a tenth of a second.
What is the deal with this? How am I supposed to transmit data and then read it? Does this have anything to do with TTL input and ST (Schmidt trigger) input? What is the difference?
Also, all diagrams I see with this device are using HT12E to transmit and HT12D to receive. Should I be using these, and what do they do? What is the advange? Please help.
rewguy