The post explains a circuit which can be used for controlling 1 to 8 appliances with a single RF 433MHz remote control handset. Now you can control fans, lights ACs, oven etc within a range of 50 meters with the same remote.
In a few of my earlier posts I have comprehensively discussed regarding these versatile and outstanding remote control modules, for reference you may want to go through the following links:
Simple RF Remote Control Circuit without Microcontroller ...
Make a Hi-End RF Remote Control Circuit | Electronic Circuit Projects
RF Remote Control Encoder and Decoder Chip Pinouts Explained ...
Main Features of 433MHz RF Remote Module
The main features of these 433MHz remote modules are:
1) These are available with different ranges, from a single channel to as many as 8 channels, which allows the user to use 8 different appliances from a single receiver unit.
2) The technology used for transmitting the RF waves are extremely sophisticated which prevents the transmitted data from getting hacked.
3) The distance of transmission is also diverse, ranging from 50 meters to 5 kms.
4) Fully customizable "address pins" which enables us to use different remote control handsets with a single receiver unit or vice versa
Although it provides us with the facility to control 8 appliances from a single RF module, as discussed in the feature no#1 above, this isn't entirely convenient because since all the 8 relays are fixed in the given receiver board could mean a lot of wiring to be done for different appliances situated at different corners of the house.
This slight inefficiency accompanied in the system compels us to think of some alternative method which would allow us to employ individual single relay modules with the desired appliances and then toggle these individual modules through a single remote handset. This option looks much hassle-free as no extra wiring is required for the installations.
Yes, that's what we would be trying to implement by exploiting feature no#4 by customizing the address pinouts of the transmitter module as well as the associated various receiver modules.
Before jumping into the circuit design it would important for us to discuss how these address pins of the transmitter/receiver are related and maybe customized for specific applications.
How Address Pins Function
If you notice the decoder chip of the transmitter module and the encoder chip of the receiver module you will find that both these ICs include 10 address pins (A0 to A9). These address pins are directly compatible with each other, meaning configuration of the transmitter and the receiver address pins should be exactly similar in order to make them respond with each other.
For example suppose if only A0 address pin of the transmitter circuit is connected with ground then the only A0 of the receiver must be connected to ground for enabling the two counterparts to "talk" with each other.
In this proposed article where we are discussing how to control 8 appliances with a single remote control we take the advantage of the above explained "address pin" feature and configure 8 different receiver modules with a single transmitter remote handset.
The following example circuit illustrates the address pin configuration of the relevant Tx and Rx modules. Here we have employed a 4 channel remote module, however a single channel module could also be employed for getting the same results, just by modifying the indicated address pins of the units.
The Receiver Circuit
The following image shows the basic configuration of the receiver module. It shows the remote control application set up for one of the 8 appliances. Similarly, 7 more receiver modules need to built for enabling the control of the associated relevant appliances.
For all the 8 units only the address pins need to be differently configured by simply changing the pin connections with ground, meaning if A0 is connected to ground for the 1st module, then A1 needs to be connected with ground for the 2nd module, A2 for the third module and so on.
Rx Schematic
The IC 4017 section forms the flip flop circuit which ensures latching up of the load in ON and OFF conditions alternately, in response to the remote button press.
The Transmitter Circuit
The following image shows the single remote control transmitter for the 8 separate receiver units as explained above.
Here pressing only the A0 switch activates the above shown receiver unit, since the A0 in the above design is connected with ground, therefore when A0 switch grounds its own A0 pin, both units "shake hands" and the signal is processed for toggling the appliance.
Similarly, switches connected across A1 toA7 can be made compatible with the remaining 7 receiver units for enabling the ON/OFF control of the attached 7 appliances located across different premises.
The diode network associated with the below shown transmitter unit makes sure that the BC557 activates and simultaneously powers the circuit only whenever the relevant switches are pressed, and otherwise the transmitter circuit remains completely switched OFF...this feature allows the battery to last for a very long time.
Tx Schematic
If you any further questions regarding how to control 8 appliances or multiple appliance with single remote, please feel free to ask them through your valuable comments.
if two or more inputs are given at the same time the Receiver section will work properly ?
Thank you!.
No it won’t work properly
I want to apply the idea into nurse calling. So that the 8 transmitters will represent the patients, while the single receiver rep. the nurse. I want at the output of the ic 4017 at the receiver to have like 8 set of LEDs which indicates the number of patients. Any suggestion pls?
Just make 8 similar transmitter units, and each one of them will be able to send the signal to the common receiver.
Thank alot i’ll implement it.
I understand it.
So now if i have 8 set of T(x) and a single R(x) both having A1 grounded can respond to each other.
The idea is can 8 set of transmitters be paired to a single receiver if they have common pin grounded. Am i right? With this i can create 8×8 set of transmitters and 8 set of receivers, the first 8 respond to the first, the second 8 respond to the second receiver upto the last 8set responding to the 8th receiver. 64 transmitters and 8 receivers.
Secondly, as electronics student is there anyway we can also contribute to this website?
Abba, Yes that sounds ok to me.
I am sorry, guest posts cannot be published in this website, but you can register in the following highly reputed website and contribute there, and also include my website name in it:
academia.edu
Okay, thanks alot your help and advice.
Regarding the circuit, can it work with antenna, i.e can i cover like 200meter wothout installing antenna on the modules?
yes, the antenna plays an important role, you can use a 3 meter long antenna to boost the range, but 200 meter is not possible with this circuit, 80 meter will be the maximum possible range
Okay, pls what is the max. Range the RF modules can cover without an antenna? I’m trying to avoid for convience.
Without antenna it may be around 10 meters.
Hi Mr. Swag
I’m thinking weather its possible to reverse the circuit, i.e 8 different set of transmitters and one single receiver, so that the receiver can respond to all the 8 transmitters. I will appreciate if you give me a hint about the new configuration. Thanks for your assistant.
Hi Abba, for that you only have to replicate the transmitters.
Thanks alot
Hi Swag
Pls is that possible to increase the Rx to 16. I want to control 16 items/appliances, is there room for that? I think about using two 4017 ic, but i think it ll not work. What do you suggest?
Abba, if a 16 channel remote chip is available then you can do it.
Okay thanks alot.
Sir the antenna that comes embedded with the rf modules, are they enough to cover the max. Frequency or we need the external antenna, for efficiency?
Abba, the built-in antenna is only a few inches long, which can be increased to 1 meter or more to increase the range significantly, otherwise the range will be quite low. So it must be increased for higher range
Dear Sir can be used this RF Module for 8 Chanel by using 2 HT12D & 2 HT12E Ic.
By Switching the -ve Supply in transmitter IC
Dear Saurabh, sorry I don’t remember the specifications of the circuit and the IC as it was written many years ago, so i am unable to answer your question correctly.
Sir if i send u some circuit diagram than can u help me for solving my problem.
Please sir….
Saurabh, I normally solve problems related to circuits present in this website, not external websites.
Hey swag, how do I send 8 parallel data at the same time with the HT12e instead of 4
Hey jiro, for sending 8 parallel data you may need 8 separate ICs, and configure their address pins in 8 unique ways.
Hey Swag
Love your web sight.
I want to build a RF module to control four 12v vehicle window motors. They are to control doors in a up and down motion stopping when ever you release the control button. I would also like to incorporate micro switches to stop the motors at the end of door travel.
Thanks
Thanks Jeff, I think the concept explained below may suit your requirement
https://www.homemade-circuits.com/simple-gate-openclose-controller-circuit/
S1, S2 can be replaced with Rx relay contacts, while S3, S4 with limit switches which must be Push-to-OFF type.
Hello sir
In transmitter circuit diagram transistor is BC547 but in article you mention BC557. So which transistor we can use.
Another question how can we figure out that signal is sending or not. Is there possible to know our remote is sending signal or not by some indicator.
Hi Jayesh, it seems like a printing mistake in the diagram, it is actually a BC557. I have corrected it now
In Tx there’s no way to know whether it is sending signal or not, but in the Rx module the pin#17 LED will oscillate when the Tx button is pressed, confirming the transmission reception
Sir i have one doubt what should we connect to ANT pin in both RSW434and RSW434.
You can connect a long flexible wire as the antenna, use around a meter long wire for best response
Hello Swagatam sir,
I have a doubt. In transmitter unit diagram pin no 13 i.e., D3 is connected to R4 as well as ground. Is this correct or we need to connect D3 pin to just resistor R4 only
Hello Jayesh, yes that’s correct, because one of those pins needs to be joined to ground for initiating the signal from the transmitter, along with the selected Address pin switch, otherwise we may have to press two switches simultaneously to initiate the transmitter, which could be difficult..
Hi Swagatam…
Do have an article here that discusses about making an RF Rx & Tx? Any frequency can do..
That would be a great help..thanks
Hi Tesla, you can refer to the following article
https://homemade-circuits.com/2013/07/simple-100-meter-rf-module-remote.html
sir ,
is it possible to build and post 8 relay circuit
NVD, you can get it from some other online website….just search for "8 channel RF remote control circuit"
sir,
i dont want 8 individual reciever circuit.i want all the 8 relays to be on the same reciever circuit.sir please provide me a circuit diagram for this.i want the first relay to operate when i press the first remote button,second relay when i press the 2nd button so on…
NVD, if you want 8 relays on one receiver, then you can simply buy an 8 channel RF remote module or build the same at home
sir
can you please provide me a circuit for the above purpose
controlling 8 applications with 8 relays placed in same reciver circuit
presently I don't have an 8 relay circuit, I have a 4 relay circuit though
sir,
could u please how can i use this circuit for controlling 8 devices.can you please explain in detail.also tell me where a1 a2 etc and d2 etc should be connected for controlling 8 devices.if possible provide me a circuit diagram for controlling 8 devices.please sir.is there any pcb available for this project.
thank you
Sir,
I would like to know like to know how to use a PIC16F630 as an encoder and decoder to build an eight(8) channel remote control.
Pls sir, I would need a detail explanation on how to build it, because am a little new to circuit building.
Thank you.
Success, sorry I do not have much idea about this…so can't suggest
Sir I succeed with pairing 433 with 9 channel using ic 74hc147 to data in 12e & ic 74ls145 out bcd to decimal for 12d, my quest is i need IR transmission, i tried several methods 38 khz 555, 74132, 40khz crystal 4093, 7400 no use, result 0, pls help me to transmit ir data without using audrino
Ramesh, I would be difficult for me to troubleshoot an external circuit, I can help only with those circuits which are published in this website
Sir pls help…how it modify for 8 out put or relay circuite
You need to make the first circuit 8 times for the 8 appliances individually and use the second circuit for controlling them through the indicated 8 switches
hello sir.this is a good circuit.without muc. i have 1Q. HT12D have 4no. output then how can i toggel 8 relay.if i make 8 relay driver stage then wher i conect it.ht12d ic have 4 output.
orrie, the above RF modules are also 4 channel type, so you can follow and build the above design exactly as it is shown, for your application.