0
\$\begingroup\$

with the use of encoders and decoders I'm able to interface more than one RF link pair at the same time, this is what the usage of an encoder looks like to me.

Are there more uses to it than this?

Does it help us to improve range and reduce noise?

\$\endgroup\$
11
  • \$\begingroup\$ Well, if instead of an OOK modulation you use a more sophisticated modulation yes, you can reduce the noise outside your band or you can increase the range. If the modulation is the same I don't think you will be able to increase the performances. What kind of encoders/decoders are you using? \$\endgroup\$
    – frarugi87
    Dec 2, 2015 at 9:24
  • \$\begingroup\$ I am not set up on the usage of encoder yet I was thinking of HT12E and HT12D pair maybe? My task is to create a RC car. Which uses PWM signals for motor control over L293D. \$\endgroup\$
    – Bhashithe
    Dec 2, 2015 at 9:30
  • \$\begingroup\$ Ok, with those encoders you won't be able to increase the range or reduce the noise, since they simply provide a "handshaking" between the two. Anyway, since you want to create a RC car, why don't you move towards bluetooth? You'll get a stronger protection, immunity to other devices (e.g. gate openers) and most important you will be able to control the car from smartphones. Nowadays BT modules are simple to use (usually they just have a serial interface) \$\endgroup\$
    – frarugi87
    Dec 2, 2015 at 9:45
  • \$\begingroup\$ Then what is a good encoder to use in that case? there's no mention about the PWM capability on the HT12 pair. If i use that would I be able to send PWM signals? I am doing this with RF is to learn it. I will somehow in a later project use Bluetooth. Since I have used XBee in another one of my projects it may be a lot simpler right? than RF i meant \$\endgroup\$
    – Bhashithe
    Dec 2, 2015 at 9:56
  • \$\begingroup\$ Well, I'm not really into RF, but I think that if you have a board which can modulate into OOK modulation you can't change it. You should look for other RF modules with a better modulation scheme, but I don't know any since when I need RF support I just use a pre-made board (nRF24l01, BT, APC220) \$\endgroup\$
    – frarugi87
    Dec 2, 2015 at 10:04

1 Answer 1

1
\$\begingroup\$

I don't have enough reputation to add a comment:

How do you intend to send the PWM value? You can send a 4 bit value as data between the HT12 pair.

The encoder/decoder do not help with the range but you get rid of false transmissions. The HT12 encoder sends the message three times and the address needs to be the same on both decoder and encoder before a Valid Transmission is recognized by the decoder.

\$\endgroup\$
3
  • \$\begingroup\$ i'd like if I have at least 256 levels on the PWM pins, just like a normal Arduino would have. could I do that with this? 4 bit seems a bit too low for that right? 16 levels is okay, but it would be better if i have more \$\endgroup\$
    – Bhashithe
    Dec 2, 2015 at 12:02
  • \$\begingroup\$ The address is 8 bits and data 4 bits so I don't think it is possible. You can also check out the Virtualwire protocol. It let's you send RF without any encoder/decoder but you need an MCU on each end. See pjrc.com/teensy/td_libs_VirtualWire.html \$\endgroup\$
    – Niklas
    Dec 2, 2015 at 12:16
  • \$\begingroup\$ So i guess i cant use digitalWrite()and write PWM data on a single pin of the encoder and plug it directly to say a servo to have it working right? too bad. VirtualWire needs two MCUs that is the problem, If i can get this working with one MCU it would be really great \$\endgroup\$
    – Bhashithe
    Dec 2, 2015 at 15:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.