We are carrying the simple to use RF remote control set, it comes with a remote control and a receiver, operating at 315MHz RF. Looking at the video to know the basic operation.
Yes, it is very easy to use it. With some modification and power, I have used it for my house lighting. Now I can control the lights using remote control and also wall switch. As the video shown, just connect the power (5V to 10V) to receiver and you are ready to control any device which is TTL compatible, just to name a few: relay, LEDs, motor drivers, AC power using Solid State Relay, fan, auto-gate, etc.
Now, if you wanted to control more than 4 outputs within the wireless range (in a house), can you do it? Without modification, you cannot do it because the operating frequency is same and it will be interference. Do not worry, the purpose of this tutorial is to show you the way to do it!
I am using LEDs to indicate the outputs, please do not constrain yourself to LEDs J 1st which is which? What is remote control and what is receiver? On the left is the remote control and sometime is called keyfob. It comes with 4 keypads and battery. On the right is the receiver. The receiver is PCB with component and a simple wire as the antenna. There are 7 header pins where the functions are: (from right)
Pin Vcc – Positive power, 5V to 10V DC
Pin VT – Valid RF signal indicator pin. When receiver receives valid signal this pin will goes high.
Pin GND – Ground or 0V of power.
Pin D0 to D3 – These are the output pins which you should connect to device you like to control. I am connecting these pins to LEDs.
The basic setup is shown in the earlier video. Provide 5V and you can control the LEDs from the keyfob, easy and straight forward.
What if I need to control more than 4 outputs? Without modification, you cannot get it because there will be interferences. Let me show you the setup of 8 outputs.
On left, I am using momentary receiver, while on right, I am using toggle type of receiver. Try to setup this, and use either of remote control (keyfob) to control the LEDs. You will notice press Key A on keyfob will trigger 2 LEDs, right? This is because both receiver receive and execute to the instruction from same keyfob because they operate at same frequency. There is mechanism for the receiver to distinguish the remote control, through addressing or ID. We can set ID for the receiver and keyfob, and the instruction will only be executed if the ID matches.
Actually, a brand new RF remote control set does have ID, which is default. Without modification, all remote control set have the same ID J
Let’s see where can we set the ID on keyfob and later we look at receiver. Open the keyfob with flat surface of screw driver from side.
You will notice there is battery and some component.
Flip the board over where you can see the keypad.
Remove the soft cover. You will see 3×8 pads as I circle. That is the pads where we can set the ID for keyfob.
Let’s have closer look.
If you look closer, you will see top row is label as H (HIGH), bottom row is L (LOW) and center row with number of 8 at left and 1 at the right. This is tri-state ID. Tri-state means there are 3 states for a pin. Center pins are the ID pins. It can be not connected, HIGH or LOW. As you see, by default pin 1 to pin 8 are not connected, that is a condition or ID, the default ID. It is up to you to configure the ID.
Now, where is the ID for receiver? As I highlighted earlier, ID of keyfob and receiver must match to enable the control. Arrange the receiver and keyfob as shown. Please be informed that the pins of receiver is facing top and is flipped over. You will see there are similar pads (3 x 8) at the bottom. The center row is the ID pins. Top of it is HIGH, and bottom is LOW.
Now, use some lead and solder the ID that you like, you can simply solder 1 of the ID pin to HIGH or LOW, just make sure you solder the same ID on keyfob and receiver. Here is my example. I have solder the ID pin 8 to LOW on both keyfob (remote control) and receiver, ID pin 1 to HIGH on both device, the rest of the pins I leave it untouched.
Now, put the keyfob back to the cover as before it is opened, also the receiver. So you have 2 set of RF remote control.
Pressing a key of left keyfob will only trigger the LED on left receiver. It will not interfere with the right receiver. Same applied to the right remote control.
OK, I am done 🙂
So how many unique ID you can get from this combination? The answer is 3 to the power of 8 = 6561 unique ID… that is a lot. And remember, if you have question, please do post in our technical forum as we seldom check the comments section in tutorial site.