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Topic: cheap 433 module - antenna please? Is this a waste of time? (Read 541 times) previous topic - next topic

DocStein99

I found a few tutorials on this 433 wireless tx module with rx receiver.  They claim it was easy but IT'S NOT.  I only spent a day reading and learning to find all the wonderful signaling that needs to go in the background, and fill me up with detailed information that I really am not interested in knowing right now.

These modules do not come with antenna's.  The tutorials do not explain about antenna.  I have to sift through user comments to find the odd person who hints around cutting 12 cm wire and twisting in random shapes.  After I finally soldered some wires to my modules, I was able to receive some data.  As long as both modules were practically stationary and I didn't breathe while holding the transmitter about 6 feet away.

Ideally, I want to collect data from my R/C robot to monitor sensors - and I don't think this module is going to be reliable for what I am looking to do, at the speed that I need to analyze graphs for voltage and current, etc... 

Is the NRF24L modules more reliable and speedy?  Is this 433 module just something I can probablyh use correctly I receive enough education for a commercial radio transmitter license ? 

PaulS

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Is the NRF24L modules more reliable and speedy?
Yes. That's why they cost more.

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Is this 433 module just something I can probablyh use correctly I receive enough education for a commercial radio transmitter license ? 
You can probably use it now. Posting your code would help. Posting a photo of your setup would help.
The art of getting good answers lies in asking good questions.

LMI1

I have had two kinds of 434Mhz systems. The first was reliable and easy and it also was more expensive. Receiver was about 50£$€. Transmitter costed like a few euros. It was from UK manufacturer and I did not buy  it from Ebay. All I needed was a serial bus. And the range was a few hundred meters.

The second was cheap from somewhere Ebay. It was hard to get it working and even the range was about 10meters.

ieee488

I have these http://www.ebay.com/itm/433MHZ-Transmitter-Module-SYN115-ASK-Wireless-Module-/201551034505

I was able to transmit from upstairs room to a downstairs room in opposite corners of the house without any problem. Used a 12" wire as an antenna.


DocStein99

I probably should have been more descriptive.  
This is what the modules look like

After many tries, I found this library and example to work (after I soldered a piece of wire)Manchester library and example folder

Soldering an insulated wire did not seem to work.  It was only by accident I wiggled them around (and mind you - the boards were on the same solderless breadboard inches away from each other).  My "antennas" had a small terminal connected to the ends of the scrap wire I was using.  It's when those terminals seemed to look at each other is when it actually started working.

I removed the terminals and stripped a 1/2" piece of copper.  This improved the reception.  I stripped some more wire - I think it did better, but I can't tell since this isn't really a scientific experiment after I got frustrated and desperate to try anything to work.  I tried coiling the bare wire around a pencil - but that seemed to do WORSE.  Forming the bare ends into QUESTION-MARK shapes seemed to do the best.

I didn't know if coated copper wire was worse than bare copper, or if I should even be using any coating.  I really do not want to know - I am not interested in making my own antenna's and learning about the R/F.  I know it's very involved, I need special tools and test equipment, I am going through HELL trying to get my FPV camera's and receivers to work - learning more than I want to know.

Like I said.  I just want reliable modules that I can send / receive a data stream from the sensors on the robot to the ground station, to process the data.  My FLYSKY r/c controller seems to create a PERFECT stream of data from the controller, to the receiver - into Arduino for me to navigate the motors.  I was looking for that same grade / quality to send my sensor data-stream back.

If the NRF24L01 modules do this - I will just be patient and keep waiting for them to be delivered.  I ordered the ones with the SMA antenna, and the other little ones with the chip antenna.  Ordered more than one module from different vendors, so hopefully - between the 6 that come to me, I can possibly get 2 of them to work.




ieee488

Like I said.  I just want reliable modules


Like I said the modules I linked works for me.

DocStein99

Like I said the modules I linked works for me.
Thank you for the link.  Do I just search for any "syn115" 433mhz receiver to work with the transmitter? 

ieee488

Thank you for the link.  Do I just search for any "syn115" 433mhz receiver to work with the transmitter?  
I would search for an eBay listing that has both the receiver and the transmitter as a set.
http://www.ebay.com/itm/433MHZ-Transmitter-Receiver-Module-SYN115-SYN480R-ASK-Wireless-Module-NEW-/311579545049


One caveat is that I bought my modules 2 years but I would buy them again if I had another project.


Paul_KD7HB

I would search for an eBay listing that has both the receiver and the transmitter as a set.
http://www.ebay.com/itm/433MHZ-Transmitter-Receiver-Module-SYN115-SYN480R-ASK-Wireless-Module-NEW-/311579545049


One caveat is that I bought my modules 2 years but I would buy them again if I had another project.


Can the setup of the transmitter and receiver change the actual channel # being used? The other day I tuned my ham radio transceiver to 433 MHz and heard perhaps a dozen different devices transmitting on channel 1. One was probably my wife's weather station. But I live out in the country and if I can hear that many devices, city living means channel 1 is pretty crowded!

Paul

ieee488

I don't recall setting a channel. I used the Virtual Wire library.

DocStein99

Paul_KD7HB: I just realized I could actually use a piece of equipment to tune into a frequency and HEAR what is going on.  Does a newbie/entry level radio receiver allow me to tune up to 5.8 ghz to hear those signals too?  Do they come with strength meters ?

Paul_KD7HB

Paul_KD7HB: I just realized I could actually use a piece of equipment to tune into a frequency and HEAR what is going on.  Does a newbie/entry level radio receiver allow me to tune up to 5.8 ghz to hear those signals too?  Do they come with strength meters ?
The quick answer is no. An entry level receiver probably stops at about 30MHz. The 433 MHz is part of the band of frequencies from 430-470 MHz that is shared between amateur radio, government radar, and the 433 part that is used by all the various devices sending telemetry data, including industrial devices running low power. Government has first priority, then amateurs, then all the rest.

There is an amateur radio band from 5650-5925, so some equipment may be available, but is usually separate converters that allow part of that band to be translated down to a lower frequency receiver.

pretty rare that you can find any regular commercial receivers for that high a frequency.

Paul

LMI1

43xMHz band is sometimes crowded. Cheap receivers are sensitive to blocking. That is, any transmitter near by may stop your receiver from working.

Edit: I hear NRF24 chips are not easy to get working without library, but they work with a library. I have tried ESP-01/8266 modules lately, they seem easy enough. But there are so many models and sellers that it is not easy to start. I was able to make a connection with AT-commands, so they can't be too difficult.

DocStein99: Your modules look just like the modules I had problems with. I cannot recommend them. But, like I said with good 433MHz modules you'll have no problems.

DocStein99

The ESP modules are for connecting to a WIFI network, which is kind of different.  I got them to work after a few confusing days translating chineese forum to figure out how or why to flash the software on it.

I think the next most difficult module to try and use would be the BLE 4.1 connecting to an android application (including trying to to write android software to transieve BLE data).

LMI1

The ESP modules are for connecting to a WIFI network, which is kind of different.  I got them to work after a few confusing days translating chineese forum to figure out how or why to flash the software on it.
Yes but so are NRF24s aren't they? I used, or tested, ESP-01 modules without flashing a new firmware. There are so many models of 8266 that it is difficult to say what they are not. But they use WLAN frequencies. ISM band 434MHz devices are easy because serial bus is usually easy.

In the 434MHz transmitter, we used just bundle of wire about right size. It was in a small box with the rest of the electronics. Receiver antenna was a fine commercial 144-400MHz antenna. It was supposed to be cut in the correct length. We didn't because it worked without any cutting.

But for those cheap modules, you also tried, I had to cut wires with about correct length, and still the range was short.

What I know the the 434Mhz ISM band antenna should be around 300/(434*4) meters. But with bad modules it wont help and with good modules anything goes.

I think the next most difficult module to try and use would be the BLE 4.1 connecting to an android application (including trying to to write android software to transieve BLE data).
I can imagine.

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