[SOLVED] quick questions about H12E/H12D

[mrkira]

1-is it possible to leave the address bits in both H12E/H12D not connected to ground.
2-can I get connect the Dout to Din directly to test the chips using 4 LEDs.
3-Is there anything else should be considered for the connections.
thanks

resources: **broken link removed**

 

[mister_rf]

1. Yes
2. Yes
3. read similar topics:
https://www.edaboard.com/threads/240565/
https://www.edaboard.com/threads/243261/

 

[mrkira]

that was quick mister_rf, thanks
regarding the VT pin, what I understood is : it's used just to indicate valid data input by using LED, and i can leave it unconnected, right ?
another point, is it possible to transfer 8 bit data using only one encoder, or should I use the 2 encoders instead ?
thanks again.

 

[mister_rf]

The HT12E is capable of encoding only 4 data bits.
A similar 8 bit encoder/decoder circuits:
https://www.northriverrailway.net/PDF/CIP-8.pdf

The VT pin goes high to indicate a valid transmission and can be used as a momentary data output and yes just for the test purposes leave it open.

 

[mrkira]

I got some problem during the testing of the encoder/decoders that I need to solve.
in the encoder part, i give that data pins values from the breadboard as 0v and 5v.
so first of all when I give all 5v(input) in the encoder, all the LEDs worked in the decoder part.
but when I grounded all the input, the output still the same, anyone knows why is this happening?
I have doubts about the input that I gave to the encoder....

 

[mister_rf]

For the HT12E encoders, transmission is enabled by applying a low signal to the TE pin. If a transmission enable signal is applied, the HT12E encoder scans and transmits the status of the 8 bits of address(A0 – A7) and 4 bits of data (AD8-AD11) serially in the order A0 to AD11.
See the attached diagram:

 

[mrkira]

using the encoder and decoder only worked fine.
but when I was dealing with the ASK modules, I grounded all the addresses and this solved my problem.
However, in theory, grounding all addresses shouldn't matter if they match in both the encoder and decoder.
thanks.