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Simple Remote control

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First off i'd like to say i love this site. It's great!

I want to build a remote control which uses RF or IR (Not sure which one yet) and the remote will house 5 mini momentary switches [on] - off - [on]. And on the receiver side it would control 5 other switches.

Each switch on the receiver end uses the same common Digital Return(ground) and another wire to activate a feature on a Data Aquisition System

For example if i wanted to reset the system i would complete the loop between the reset wire and the ground wire.

Here my questions:

1) Do i use RF or IR or something else?
- I need to transmit the signal anywhere from 5ft to 300ft depending on the situation And the signal will have to travel through a Armored Hummer. So i think i just answered my own question. I cant use IR. I have to use RF or something else which im not sure if there is any other method.

2) Where do i start?
- I'v never built a transmiter or receiver and im not sure of what componnts i would need to control 5 individual switches.

Thanx for any help and im sorry if i bored you. i was trying to be specific.
Sorry if i bored you...... HAHAHAHAHA!!!!!!!!!! Please. That's way too hard when I'm at this website. :lol: :D So don't worry about it. You should see some of my posts. Anyway, please tell me... can you either cut it down to 4 switches, or, make use of 3 more and bring it up to 8? Tell me this, and I can help you. :wink:
well i have 9 functions that i need to be able to activate. so with 5 on off on switches it allows me to control upto 10 functions. but i only need 9 of those.

Also the system has a RUN light. I was thinking, would it be any harder to make that a tranceiver or something so that the system can send me a signal letting me know if that run light is on.

Thanx for the reply
Well, this is what I know. I'm going with Ming transmitters and receivers. So, there is a website, that has the transmitter and receiver encoder and Decoder chips, that you must hook up to the actual Ming transmitter and receiver boards that they sell. They have 4-bit (to control up to 4 relays) and 8-bit (to control up to 8 relays) as their chips. That's what I know. Go here for about everything you need to know about the Ming Transmitters and Receivers. (This is the website I was talking about.)
You say 8-bits. can you clarify how this works.. When i think 8bits i think of 2^8 which would give me 16 differnt combinations.

So i could have up to 16 inputs and each input would create a digital output of 0 to 15

binary beeing

0 0000
1 0001
2 0010
3 0011
4 0100
5 0101
6 0110
7 0111
8 1000
9 1001
10 1010
11 1011
12 1100
13 1101
14 1110
15 1111

This would be output in serial format and inserted into some FM circuit (its been so long since i did FM i cant remember how to do this really) and transmitted to the decoder where it would be returned to its parallel format and somehow switches a relay

can anyone else fill in the blanks
You could also use DTMF encode/decoder pair.
Or...juse a PIC -->

And yes, you are somewhat right, with 8 bits you have 256 different combinations and with 4 bits you have 16 combinations :wink:

Sorry but I can't help with transmitters/receivers as I am also stuck on this subject...
:?: 8 what? outputs? combinations? Can you please clarify that...
Like I said before, with 8 bits you have up to 2^8 = 256 combinations (0 to 255). You don't have to use all combinations but they are still there.
:? Check out the site and tell me what you think. 8 bits meaning, say... 8 relays. Is what I'm pretty sure they mean.

Edit: But I could be wrong.............................. :|
Yep, there are 8 bits, but that doesn't mean that you can only control 8 relays. Let's take 2 bits as an example. With 2 bits you can control max. 4 relays because there are 4 possible binary combinations:

1. --> 00
2. --> 01
3. --> 10
4. --> 11

In order to control 4 relays in this example you would have to use an IC that converts binary input to decimal output. This IC would have 2 data inputs and, therefore, 4 outputs. Depending on the input combination, only one of the outputs would be enabled. Such ICs are 74HC155, 74HC237, HC4515, etc.
Of course, nothing forces you to use additional circuitry. I think the main reason why people usually use X bits for controlling X relays (or some other switches) is simply because it is cheaper and easier to do. I also do this.

I think I got a little bit off the topic here, right?

:arrow: My point is: no matter how many bits are available you *can* use up to 2^<No. of bits> possible combinations. How many will you use depends only on you and your needs.

Hope you understood some of this. If not, feel free to ask me and I will try to clarify things as much as I can.
Its probably a three bit
fed to a three to eight expander,
driving eight different relays.

If so,
then only one would be driven at a time,
so you would have a problem plexing up
from them.
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