In this post I have explained 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.
Discussion & Solutions
Hello ,
I am making astronomical timer using atmega 32
Here is a pro lem with memory . I set the coordinate in system it store in memory , if i switch On/Off the system some time interval ( 2-3 Sec. ) Tjen memory ok but if on /off system very quickly again or again then coordinate reset ( 00.0000).
Plz tell me what is tje problem in circuit.
Hi, My microcontroller knowledge is not good, so I cannot solve your problem. Sorry about that.
Ok Thanks
Hello sir , i am a viewer of swagatam since 15 years , i faced a problem with rf 434 amhz.
If a single Transmitter is transmitting the data in case all car centeral lock remote does not work which is in range of transmitting transmitter.
One transmitter jammed all the transmitter .
Please tell me What is the solution .
Thank you so much Prashant.
As you will understand, such problems cannot be judged without checking the circuit practically. So without practically checking the situation it can be impossible to troubleshoot the problem. I think you should consult an automotive technician in your area for solving this issue.
Thank you for your reply but it this is not only my problem if you check any RF 434 or RF 315 Mhz Transmitter module then found every module have this problem .
You can test at your end. And viewer can test.
If one receiver transmeet data same time other transmitter can’t work in range of transmitting module .
I have so far tested only a single pair of these transmitter/receiver units, so I am not sure about this issue. Try adjusting the antenna wire or connect a 12 inch long flexible wire to the antennas of each receiver.
Sir thanks for your site and care,pls I need complete circuit of 4 channel remote control to turn on and off my 4 different home appliances any time I need them
Sir thanks a lot for this article. I have a question: if I press two or more switch at the time, the receivers go on/off simultaneously or there is a sort of priority?
Thank you again.
Hi Filippo, the receivers will switch simultaneously when more than one button is pressed.
Obinna, the schematic for 4 channel remote is already explained in the above article…..you just have to configure the pin#10, 11, 12, 13 accordingly.
Sir am a beginner in electronics so what I saw in that diagram is one relay and I need 4 relays as 4 channel controller so please where can I fix the other three relays
Obinna, you will have to build the following circuit, and connect the A, B, C, D points with the 4 separate 4017 IC flip flop circuits.
https://www.homemade-circuits.com/simple-100-meter-rf-module-remote/
Sir please all the ic in those circuit are they already programmed or should I be the one to program it myself
They are all pre-programmed, you just need to configure the pins as per the shown diagrams.
I will need the diagram
why is pin 13 (D3) grounded and 10,11, 12 not, in the Tx circuit?
Thanks for pointing it out, I have corrected the mistake.
Thank you for this correction????
Actually, the previous diagram was correct 🙂
I just forgot that pin#13 was deliberately grounded, as it would be normally implemented when a switch is used between pin#13 and ground.
so when pin#13 is grounded and pin#1 is also momentarily grounded via switch , there is output on pin#13 on the Rx and switches on the relay permanently , and will be turned off when pin#1 on Tx is
grounded again; is this conclusion right? if not, how could this be done in anther way??
CLEAR, THANK YOU SIR!
Glad it helped!
A0 to A7 work like compatible ON/OFF switches for switching the Rx load ON/OFf. Pin13 of Tx corresponds to pin13 of the RX, so pin13 of Tx must be connected to ground for enabling the generation the required Rf signal at the pin13 of the Rx.
Please Sir are the switch momentary type?
Please I needed your help. I wanted to use the above design to control fan regulator for switching 5 level speeds of a fan.
Lawal, switches are not momentary, and this particular circuit cannot be used for 5 step fan dimming.
Please Sir could you provide me with a design using rf transmitter and receiver to control 5 level speeds of a fan?
We can perhaps modify the last circuit from the following article. Please build the last design without the IR sensor, and manually confirm the response of the circuit. If it works for you, then we can configure the RF remote with the pin#14 of the IC 4017 accordingly:
Remote Controlled Ceiling Fan Regulator Circuit
Please Sir,does the tx used momentary push button switch?
How to make it use momentary push button switch to enable sudden change of transmission as in remote control button
Lawal, the switches shown across the address pins are all SPDT switches, they are not push buttons, you can use different combinations of those switches to switch specific sets of receivers and loads
Hi Swag,
Is there a chip that has more than 8 channels?
Say, 12, 16, or more?
best regards.
Hi Nelio, yes, it seems they are available on amazon.
Hello, how can I control 8 DC motors with it?
You will have to make 8 of the receiver units for controlling 8 motors separately
Please Sir,will you attach the remaining modules at the output pins 12,11,and 10 of the Same Decoder IC HT12D for controlling 4 appliances,while the remaining 4 appliances control modules being attached to another Same HT 12D output pins 13,12,11 and 10 to complete the total modules for the full 8 appliances ?
It will be identical to the pin13
Dear Swagatahm
I intend to connect this one circuit diagram to an eight dc motor? If possible how can it be rotated in reverse and forward? As well as how to control its speed? please answer
Dear Vinod, operating 8 motors with speed control and reverse forward cannot be done with this simple design
Hello Swag,
Here I am trying to implement this Project with little bit modifications which are I have to use one Tx and Rx. At Tx side when I press 1 switch at that time Rx side 1 relay on and same switch press again it should be off like that I used 4 switch and 4 relay. I have found some questions regarding this article,
1) May I 4 input switch at Tx side for control 4 relay at RX side?
2) What are the value of C3 Capacitor?
3) Can you share some video if you have for this simulation perform. I hope this works fine.
Hello Milan, yes you can use 4 channel Tx, Rx unit.
C3 can be any capacitor between 1uF/25V an 10uF/25V.
I do not have any video but as we all know that these Rf modules are highly reliable and will always work.
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.
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?
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.
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
Thank alot i’ll implement it.
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.
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
Okay thanks alot.
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 I have 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://www.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…
presently I don't have an 8 relay circuit, I have a 4 relay circuit though
sir
can you please provide me a circuit for the above purpose
controlling 8 applications with 8 relays placed in same reciver circuit
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,
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.