433 MHz

[pedro gomez]

Hi Folks:
I want to test the transmission at 433 MHz since there is a Tx and Rx Orange socket, in Hobbyking, that I can adapt in my Futaba FC-18. I remember seeing some post in the forum but I do not get results in the search.
I have some questions:
- Has anyone checked whether the depth of reception in vertical is greater or less than the usual frequencies, in my case 35 MHz?
- Has anyone had reception problems in the distance-depth combination?
- the values of signal reception (between 1000 and 2000 microseconds, for arduino sketchs) vary somewhat with respect to the lowest frequencies (in my case 35 MHz).
- Some interference problem with other users?

Thanks

Pedro

[Ralph --- SSBN 598]

Good morning.
To start, I know nothing about 433mhz or arduino.

I do know Tim has worked with both of these and did a seminar of the subjects.
It was posted here.
If you haven't already read it, you might give it a look.

http://subcommittee.com/forum/showthread.php?32640-433mhz-links-and-info-(Tim-s-Regatta-Seminar)&highlight=arduino

[thor]

I have a brand new 433 Mhz Tyrannis unit for sale that works beautifully. Depending on the mineral content of the water I get between 2-3 foot of solid contact. I'll make you a great deal, if you're interested. I've never had any issues with distance, but 50 meters is about as far as I've ever sailed submerged. Never any interference issues.

[pedro gomez]

Hi Ralph:
Thank you, yes, that's what I remembered seeing. Very interesting. It Solve my doubts.
Hi Thor:
I have a Futaba FC-18 Campac, with a 35 MHz RF Modul, and a 2,4 GHz Modul. I'm buying in Hobbyking, a 433 Module and receiver from Orange.
2-3 foots it is shallow reception. I would like to have like with 35 MHz: 2 m of reception in depth
Best Regards Guys

[thor]

You will not get 2M of penetration with 433 Mhz.

[pedro gomez]

Finally I decided to test 433 MHz. Orange devices in my Futaba FC-18. I have not yet verified how deep this frequency will allow me be submerged, I read less than 2,5 meters, which is what I now had with 35 MHz, but I am interested in migrating to 433 for the obvious advantages.
However, when trying a sketch in which the PinChangeInt function intervenes, for the reading of channel 8, where I have a multiswitch, I see that the readings of the 8 pulses is not correct. I re-test with 35 MHz and all is OK. Maybe the problem is in the reference pulse, or something else ... I do not know. Now the void for multiswitch reading is like this:

void calcPulseCh8 () // Multiswitch 16
{
**if (digitalRead (Ch8) == HIGH)
**{
****ulPulseStartCh8 = micros ();
**}
**else
**{
****ulPulseInSharedCh8 = (uint16_t) (micros () - ulPulseStartCh8);
****current_switch16 ++;

****if (ulPulseInSharedCh8 <1000)
****{
******current_switch16 = 0;
****}

****if (ulPulseInSharedCh8> 2000)
****{
******current_switch16 = 0;
****}

****if (current_switch16 <9)
****{
******multi_switch16 [current_switch16] = ulPulseInSharedCh8;
****}
**}
}



Thanks
Pedro

[pedro gomez]

Hi.
At this moment, I read a past Thread with Tim Senecal about this and he said:

"I was trying to use this with my 433mhz modules, but the 9th sync signal is interpreted by the transmitter module as a bad value, and thrown away, so i cant use this code with the 433mhz modules. the same thing happens with the 2.4ghz modules made by other manufacturers. I have only tried the code with FM receivers, I haven't yet tried it with PCM receivers."

So.....bad luck.

[cheapsub]

may be you can try this, up to 16 servos!

http://www.itluxembourg.lu/site/ulrs-additional-channels/

[pedro gomez]

433 MHz and Multiswitch Robbe-Futaba

Thanks for the info, Cheapsub.

Yeah, it is an interesting thing, but that's not what I need. My need is how to (if it is possible) modify the transmitter's software , to tell it not to interpret the control pulse generate by the Multiswitch encoder, wich value is less than 1000us, to transmit it to the receiver. Because Tim Senecal says the 433 MHz LRS Orange transmitter interprets it as an erroneous value

This is the encoder:

http://www.roi-import.com/product_info.php?products_id=8750

and this the decoder:

http://www.roi-import.com/product_info.php?products_id=8746

although I replace that decoder with arduino and the PinChangeInt function