(09-03-2015, 17:06)meteoestarreja Wrote: since you're testing just with a fence wire, you could forget about GND for now, since using just a simple wire, you must connect it, to the ANT pin and nothing else.
OK. Thanks for the explanations.
Once I receive the proper SMA antennas should I connect one of the GND pins (I guess the one next to the ANT) from the module to the external 4 pins of the PCB SMA connector (just for testing sake)?
Quote:By the way, try with 16cm and not 18cm
Does not seem to help. Also changed from fence wire to copper wire from TV coaxial cable and it does not seem to improve.
The curious part is that without anything working as an antenna, just a couple of centimeters (more than that it does not work) away from each other, the lower quality XD-RF-5V /FS1000A couple seems to produce a more steady result. I mean the RX signal is constant.
With the 3400 RF Kit, while TX remains constant, on the RX side I get something like 5-10 constant receptions, one (very) slight pause, another 10 constant receptions, one (very) slight pause....
It may be somehow related with software and the Virtualwire library. Also, it crossed my mind that such a thing as a "minimum distance between the TX and RX antennas working at any given frequency" must exist!? I am keeping them just 4 cm apart, which does not seem right. I need a second test board so I can separate them a few meters and simulate more real working conditions.
The point being making sure all parts are in good working order before any soldering begins.
BTW, while at it, I noticed that when the RX module alone is ON I pick some noise on the portable radio. I also noticed that TX seems to be best picked by the radio at around 434.005-15. Another thing which I am sure some principle of radio propagation may explain is that as I walk further away from the TX the signal seems to be better received
on the portable radio at an incrementally slightly higher frequency....
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About the second question and without using additional hardware, I'm not imagining an arduino measuring signal strength at least with accuracy.
It seems a few 433Mhz modules used with Arduinos include RSSI, which is not the case. Somewhere (I am afraid I lost track of the link) I also read about a procedure with code which seems to make sense: a simple test of the TX/RX link can be achieved by systematically sending a known number of packets in the TX and then count exactly how many were received and or lost in the RX.
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You could try for example use a "special" TV dongle (you can find it very cheap on ebay) and use SDRSHARP with it.
Yes. I have heard about those before. I do have an USB TV-Radio dongle (Avermedia) but it does seem to have a supported chip. I have to persuade myself to buy another. I believe Box-Jumbo/Auchan sell a cheap OEM model which judging by the looks should be compatible. I will try to check next time I go there.