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Topic: Servo Motor doesn't move although 5V (Read 5185 times) previous topic - next topic

OldSteve

The "take-home message" here is that a proper antenna - the dipole - is substantially cheaper and probably more effective than a massive increase in power.
But bulky and slow. And not more effective. Try and get 1000m line-of-sight out of those cheap, Chinese modules.
And an APC220 isn't what I'd call a "massive increase in power". 20mW isn't massive by any means.
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Rachmaninow

#31
Nov 22, 2015, 11:05 am Last Edit: Nov 22, 2015, 11:19 am by Rachmaninow
Hey,

I reduced the transmission speed from 5500 to 2000. Also i brazed a 17,3cm long wire to the GND of RX and TX.
Didn't change anything. I'm so disappointed.

I dont want to achieve more than 1000 meters. I just want to achieve atleast 100 meters... There must be something that blocks my signals i think

OldSteve

Hey,

I reduced the transmission speed from 5500 to 2000. Also i brazed a 17,3cm long wire to the GND of RX and TX.
Didn't change anything. I'm so disappointed.

I dont want to achieve more than 1000 meters. I just want to achieve atleast 100 meters... There must be something that blocks my signals i think
Is that 100m line-of-sight, or through obstructions?
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Rachmaninow

#33
Nov 22, 2015, 11:33 am Last Edit: Nov 22, 2015, 11:49 am by Rachmaninow
line-of-sight. It's a motion tracking system (TX) and the RX-Side is on a drone. So it shall be a 100m line-of-sight. Would be nice to have more range, but 100 metres is the first goal..

Look at my attachements above. Is this "dipole" antenna correct? m not sure if i understood it right.

OldSteve

#34
Nov 22, 2015, 12:10 pm Last Edit: Nov 22, 2015, 12:10 pm by OldSteve
line-of-sight. It's a motion tracking system (TX) and the RX-Side is on a drone. So it shall be a 100m line-of-sight. Would be nice to have more range, but 100 metres is the first goal..

Look at my attachements above. Is this "dipole" antenna correct? m not sure if i understood it right.
Sorry, but I'm no RF expert, so can't help much.
Hopefully someone more knowledgable on the subject will help more on dipole design.
(As I mentioned, when I want longer range, I just use a better transmitter/receiver.)



0
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Paul__B




It is a bit tricky since the actual modules appear to be underneath the circuit board, but your antenna pieces seems to be connected to tracks that are in turn connected to the modules rather than connected to the ground and antenna points on the modules themselves with nothing else connected to the antenna terminal as jremington illustrates.  With these RF frequencies, distance is critical (and so is capacitance).

Of course, there may be other matters still affecting the performance.  Given that it is a "real" antenna rather than one of those zig-zag patterns on a PCB, a module that includes the antenna will clearly be much easier to work with.


Rachmaninow

So i am at the end of this "cheap" transceiver kit? You also recommend other Hardware, like this APC220?

Never thought, that would be so hard.

OldSteve

So i am at the end of this "cheap" transceiver kit? You also recommend other Hardware, like this APC220?

Never thought, that would be so hard.
You get what you pay for, in my opinion.
There's no guarantee that even an APC220 will be the answer to your prayers, if you're in an area with a lot of noise in that band, but at least something like an APC220 would give you a better chance, and you can alter the frequency between 418 and 455 MHz to avoid that noisy 433.92MHz band. There are other similar modules with higher power too, but for my purposes it's all I need. (And I have actually seen one get a 1km range, but it was over water, from one peninsula to the next.)
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Rachmaninow

mhmm...

Whats about this:

http://www.seeedstudio.com/depot/2KM-Long-Range-RF-link-kits-w-encoder-and-decoder-p-321.html


OldSteve

#39
Nov 22, 2015, 01:33 pm Last Edit: Nov 22, 2015, 01:38 pm by OldSteve
2km is a loooong way. To be honest, I'd have to see it to believe it. One way to find out.....

I do know a bit about the encoding. I use the PT2262 and PT2272 remote control pairs a lot.
Those modules have 4-bit data, 8-bit tristate address, (38). They send each packet twice, so they're fairly slow. The effective speed is half of that claimed as a result. The receiver's Vt pin goes high when valid data is received.

Edit: You're obviously dead-set against using anything decent, so why not give them a try?
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Rachmaninow

#40
Nov 22, 2015, 08:58 pm Last Edit: Nov 22, 2015, 10:26 pm by Rachmaninow
Yea, the speed is what i worry about. And 2km is too much. It would be nice to have a antenna with maybe 500-1km, easy handling (coding!)..
Are  there no other Arduino users with the same problem?

@OldSteve:
Im looking for a serious shop to bye a apc220 module. There no serious german shops i think? I found only this:

http://eud.dx.com/product/arduino-apc220-wireless-rf-modules-w-antennas-usb-converter-844143011#.VlIx0-KUQ4c

http://www.dfrobot.com/index.php?route=product/product&product_id=57#.VlIyUuKUQ4d

And it has very long shipping... i have a time issue :(

OldSteve

Yea, the speed is what i worry about. And 2km is too much. It would be nice to have a antenna with maybe 500-1km, easy handling (coding!)..
Are  there no other Arduino users with the same problem?

@OldSteve:
Im looking for a serious shop to bye a apc220 module. There no serious german shops i think? I found only this:

http://eud.dx.com/product/arduino-apc220-wireless-rf-modules-w-antennas-usb-converter-844143011#.VlIx0-KUQ4c

http://www.dfrobot.com/index.php?route=product/product&product_id=57#.VlIyUuKUQ4d

And it has very long shipping... i have a time issue :(
Sorry, I'm in Australia, so can't really help with a supplier. I buy mine from an eBay seller, and it takes 3-4 weeks for them to arrive.
Of the links you provided, http://eud.dx.com looks like they'd be faster. (Much cheaper, too.)
You could also search for "Dorji DRF7020D13". It's exactly the same thing, made by a different manufacturer.
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

jremington

#42
Nov 23, 2015, 05:24 am Last Edit: Nov 23, 2015, 05:28 am by jremington
The 434 MHz dipole design I use has colinear elements, and the elements are slightly shorter than 17.3 cm, for an overall end-to-end distance of 32.8 cm.  It works far better than anything else I have ever tried.

The "rabbit ears" arrangement shown in your photos is counterproductive and will work very poorly in comparison.

Dipole antennas are quite directional. The transmitter and receiver dipole must be parallel to each other for maximum range. I have both transmitter and receiver antennas in the vertical plane, about 2 meters off the ground.

The antenna was designed using a free version of the professional quality program MMANA-GAL.



OldSteve

#43
Nov 23, 2015, 05:36 am Last Edit: Nov 23, 2015, 05:37 am by OldSteve
The transmitter and receiver dipole must be parallel to each other for maximum range.
This part will be a problem when controlling his drone, when it's not close. The angle between the antennas will be constantly changing. I guess he can swing the transmitter, but the receiving antenna will rarely be parallel to it.
"Vertical plane" - I overlooked that. Reading too fast. :D
Please do not PM me for help. I am not a personal consultant.
And others will benefit as well if you post your question publicly on the forums.

Rachmaninow

Well, I formed it to parrallel antennas, but the range came down to 5 metres... So 1 antenna works for me best i think. damn :/

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