Currently I am using a separate wire-coil antenna for each of these: For the receiver it is directly located within the device but for the "longer" range transmitter I am using a external connector so that I could mount the actual antenna on top of a 5m pole (connected via some coax cable)..
Physically the 2 antennas are pretty much the same.. but I expect that the one located within the device might cause me trouble due to the aluminum box that the device is in (and which might shield the signal).
If instead I could be using my external antenna also for the ASK receiver that would provice for a nice clear line of sight from everywhere.. but is that a good idea or would the transceiver and the receiver (connected to the same antenna) interfere with each other?
srnet:
So much easier to stick with one tranceiver module.
The Si4432s can be got for around $2, they are really so much better, lower power etc, and reliable than the cheap ASK modules.
Capable of a great deal more distance than a mere 100M too.
You may have noticed that I am already using a Si4432 based transceiver for the "longer" range communication? However from personal experience I have several reasons why I do not want to use one of those in my sensors:
the cheep ones usually come with a 1.27 pin header.. for me those are just a fucking nightmare to solder
they are very fragile: I have meanwhile 5 dead ones lying around.. initially they work and suddenly they are just dead/dont work anymore (maybe due to my "work in progress" or due to the point 4 below..)
for the above reasons I had switched to using more expensive versions that come with 2.54 headers: however these cost about 4$ as compared 0.5$ for the ASK transmitter
when you need an additional transceiver you have to be careful to get the exact same model.. I have meanwhile seen 3 different "revisions" of the respective "blue" transceiver (see link in my original post: with minimal layout changes on the respective PCBs). Many sellers on aliexpress use photos that do not match the actual product - so you might get a "different version". Unfortunately those different revisions are often just incompatible with other revisions (I don't know why.. maybe the crystals are not 100% in sync..whatever). You'll have to be very lucky to get a new transceiver that actually communicates with the ones that you already have.. (I meanwhile had to buy 3 new ones because I could not find 1 new one that would work with the 2 that I already had.) This is just bloody annoying.
The HC-11 is similar to the HC-12 but is lower power and cheaper.
Note that HC-11s wont talk to HC-12s.
Thanks for the link.
But "Bluetooth replacement" does not inspire much confidence that this is actually meant for longer distances... what makes you think that this is actually better than a Si4432 based transceiver? (my "1000m" SI4432 barely makes it through the roof and about 50m - I doubt that a "200m Bluetooth" would be an improvement)
srnet:
The differance between good line of sight propagation and what you might get in or around buildings can be well in excess of 1000:1.
So whilst a device might quote as '1000M' or '200M' its meaningless unless you know exactly where its being used.
obviously this is the range that might be obtained under the most favorable conditions.. the kind of number that marketing ppl like to use..
.. still I doubt that the proposed transmitter (that operates in the same 433mHz band as the Si4432, and where even the marketing guys already are more conservative regarding optimum conditions performance) should be a "superior" to the Si4432 that I already use.. but I would of course like to see evidence for that claim
If you must use the cheap 433 Mhz OOK radios , then buy the superheterodyne type receivers and not the superregen types which are deaf and also noisy, they will interfere with any other 433 receivers which are nearby.
The superhet receivers have a crystal or SAW resonator on the PCB, and not a coil.
wothke:
obviously this is the range that might be obtained under the most favorable conditions.. the kind of number that marketing ppl like to use..
But its not the range under most favourable conditions, that is part of the problem of decoding what manufactures say, they usually dont gove the circumstances behind the claim.
Under the most favourable conditions, very good line of sight, the Si4432 is good for around 60km @ 100mW and simple 1/4 wave wires for antennas.
mauried:
If you must use the cheap 433 Mhz OOK radios , then buy the superheterodyne type receivers and not the superregen types which are deaf and also noisy, they will interfere with any other 433 receivers which are nearby.
The superhet receivers have a crystal or SAW resonator on the PCB, and not a coil.
Thank you for the explanation. I am already using respective superheterodyne type transmitters and indeed it might be time to also replace the respective receiver.
srnet:
But its not the range under most favourable conditions, that is part of the problem of decoding what manufactures say, they usually dont gove the circumstances behind the claim.
Under the most favourable conditions, very good line of sight, the Si4432 is good for around 60km @ 100mW and simple 1/4 wave wires for antennas.
whatever.. with trees, buildings and other sources of interference those numbers are pretty worthless... still if 1000m is quoted for one product and 200m for another product, that might either be an indication that the latter product tends to have less range or it is an indication that one of the two manufacturers just uses more shameless sales people.. but that is beside the point:
mauried had suggested to replace my existing Si4432 with an HC-11 and I am still curious to learn if there is any evidence to back that idea...
Your original question was can antennas be shared, and the simple answer is no.
I only suggested the HC11 radios as they only need a single antenna.
I cannot comment at all as to whether they will meet any other needs you have.
If you need long range, then HC12 are higher power but more expensive, but again as to whether they will work in your situation is anyones guess.
