Questions about 12 channels RF remote control

[Saeedk9574]

Hi every one,
I have a few questions about the board of this RF remote control.
1. First of all this board uses ev1527 encoder. Although this IC has just 4 pins for buttons, this remote control has 12 buttons. How they have done such thing?
2. The second question is about the usage of these diodes (or maybe zeners). I can not understand why the have used these amount of diodes which is around 20.
3. Can I increase the range of antenna by adding extra antenna (not the TE one the two wires one)? If so, how should I calculate turns and length of them.

 

[KlausST]

Hi,

I guess - with the PCB in your hands - it´s more convenient for you to draw the schematic of the circuit.... than for us.

Klaus

 

[Saeedk9574]

Hi every one,
I have a few questions about the board of this RF remote control.
1. First of all this board uses ev1527 encoder. Although this IC has just 4 pins for buttons, this remote control has 12 buttons. How they have done such thing?
2. The second question is about the usage of these diodes (or maybe zeners). I can not understand why the have used these amount of diodes which is around 20.
3. Can I increase the range of antenna by adding extra antenna (not the TE one the two wires one)? If so, how should I calculate turns and length of them.

4. In 4 channels remote control, when we press a button we send a 24 bit unique data. After 20 bit address we have 4 bit data for buttons. Now imaging one button data is 0010 and another is 0100. Now if I press two buttons which data will be sent. that would be 0110 or other thing?

 

[KlausST]

Hi,

4) would make sense.
Just do some tests. We can not do them for you.

Klaus

 

[Saeedk9574]

Hi,

4) would make sense.
Just do some tests. We can not do them for you.

Klaus

If you do not have answers do me and yourself a favor, and do not reply

 

[FvM]

If you do not have answers do me and yourself a favor, and do not reply

Consider that forum members may ask questions about details missing in your post or make suggestions how to proceed even if they don't know the answer.

--- Updated Jul 14, 2024 ---

Technical related, I imagine that 1 out of 16 buttons pressed can be binary coded into 4 bits. If you don't find a reference schematic, I support the idea to "decode" your PCB wiring.

 

[KlausST]

If you do not have answers do me and yourself a favor, and do not reply

Ah attitude.
Too lazy to do the tiniyest bit of work on your own.

I agree with you: I don´t need to support this.
I will not bother you again.


Klaus

 

[Saeedk9574]

Consider that forum members may ask questions about details missing in your post or make suggestions how to proceed even if they don't know the answer.

--- Updated Jul 14, 2024 ---

Technical related, I imagine that 1 out of 16 buttons pressed can be binary coded into 4 bits. If you don't find a reference schematic, I support the idea to "decode" your PCB wiring.

Thanks for your reply
Consider people like me are beginner that they ask such questions. Not only this person did not ask for more information but run down me.

As an armature I provided the information I know. if there is other useful information, member can ask to sharing them.

--- Updated Jul 14, 2024 ---

H

Ah attitude.
Too lazy to do the tiniyest bit of work on your own.

I agree with you: I don´t need to support this.
I will not bother you again.


Klaus

Here you can see other members answers for same question in other forums without putting down.

the diodes are probably used for a wired-or circuit to activate multiple pins with one button press

It looks like the diodes in the schematic are there to allow the ic to be powered when a button is pressed, and unpowered when a button is released.
Presumably the extra buttons on the board are wired such that multiple input pins are driven by each switch, allowing a maximum of 2^4 switches to be implemented

The 12 buttons are connected through the diode matrix to select 12 of the sixteen possible combinations of 4 bits on the input.

 

[FvM]

The 12 buttons are connected through the diode matrix to select 12 of the sixteen possible combinations of 4 bits on the input.

This answers Q1 and Q2. As for Q3 you achieve maximal range with matched antenna length (e.g. lambda/4) and impedance. Telescopic antenna is rather unusual for remote control, thus I guess it's already range optimized.

 

[D.A.(Tony)Stewart]

This encoder uses each switch to encode 4 bits using diodes for logic 1 to 4 inputs, so it supports 15 buttons to apply power to the LED and the encoder and the sense input bits.
1010 2 diodes
1001 2
1000 1
0111 3
0101 2
0100 1
0011 2
0010 1
0001 1
0000 power off.

How many diodes total is this?

I doubt you can extend the range unless you have a wired connection with antenna coils at each end to couple the signal to the target receiver antenna with some matched impedance.

Reducing the emitter resistor 50% may help a bit.

 

[Saeedk9574]

This encoder uses each switch to encode 4 bits using diodes for logic 1 to 4 inputs, so it supports 15 buttons to apply power to the LED and the encoder and the sense input bits.
1010 2 diodes
1001 2
1000 1
0111 3
0101 2
0100 1
0011 2
0010 1
0001 1
0000 power off.

How many diodes total is this?

I doubt you can extend the range unless you have a wired connection with antenna coils at each end to couple the signal to the target receiver antenna with some matched impedance.

Reducing the emitter resistor 50% may help a bit.

Thanks a lot.
Even we can extend it to the 16.

 

[D.A.(Tony)Stewart]

Thanks a lot.
Even we can extend it to the 16.

ok to 16 to include 0000 since the button also supplies power. But since the current is < 2A they must be gold-plated buttons for reliability or if not have an e-cap to wipe oxide off the contacts on the circuit.

 

[jessica5]

I have a few questions about the board of this RF remote control.
1. First of all this board uses ev1527 encoder. Although this IC has just 4 pins for buttons, this remote control has 12 buttons. How they have done such thing?
2. The second question is about the usage of these diodes (or maybe zeners). I can not understand why the have used these amount of diodes which is around 20.
3. Can I increase the range of antenna by adding extra antenna (not the TE one the two wires one)? If so, how should I calculate turns and length of them.

The EV1527 encoder is limited to 4 pins, but manufacturers often expand functionality using multiplexing techniques or matrix configurations to handle more buttons. The diodes, likely used for isolation or to prevent backfeed in a matrix setup, play a critical role in ensuring proper operation. As for extending antenna range, adding another antenna could work, but antenna design is tricky. You'll need to consider frequency, length, and turns to avoid interference or signal degradation. Calculating these precisely requires understanding the operating frequency and ensuring the antenna is correctly tuned.

 

[jessica5]

You've answered Questions 1 and 2 perfectly! Regarding Q3, you are 100% correct—matching antenna length and impedance improves range. Since most remotes don't include a telescopic antenna, the device is probably already tuned for range, guaranteeing effective signal transmission without the need for any changes.spelling bee answers