Transmission works with wires but not always with wireless

[languer]

I am using the Laipac 315 MHz RF modules and I serout only once and it works with wires 100% of the time. When I try wireless it works once in a while. On the other hand, when I serout 5 times the wireless works most of the time but does not work once in a while. I have added 4 $55s for a preamble and manchester encoded everything.

I think skimask has a very good point. You started with the statement above and are now deeper than you could ever imagine. There is a subtle truth to the KISS principle, it works and it is simple.

• What are your expectations?
• Do you have something that works 4-out-of-5 times? I mean you send the message 5 times and you receive it 4.
• Where you expecting the link to work 100% of the time? If so, do you know what your link budget is? Do you now how much margin you have? What distance you need to cover?
• I do not know of any comm system that works 100% of the time. The best systems (very expensive) use redundancy, error correction, complex modulation schemes, etc. Normal systems (i.e. remotes, sensors, telemetry) usually just encode and send several times.
• You pick what you think you need in terms of reliability and no more usually. If you have way more, you over-designed it (your wasting battery power, causing unintended radiation, or something else).

I am not trying to persuade you from making something better. But seeing how complicated it is getting, do you really need it this complex? Or can you keep your manchester coded signal (which apparently is already working) send it a few times and only use the first one that passes a CRC check or something like that?

[skimask]

I think skimask has a very good point. You started with the statement above and are now deeper than you could ever imagine. There is a subtle truth to the KISS principle, it works and it is simple.

And one other point I might make...
The 432-433Mhz modules seems to work, the 315 doesn't.
Why not use 2 432-433Mhz modules, one master, one slave. Sure you can't use them both at the same time, bidirectionally. But for instance, maybe the slave will ONLY answer after the master has spoken. Use a PICs pin to provide power to the modules, turn off the master's receiver while it's transmitting, turn off the transmitter while it's receiving, and so on with the slave, only the other way around in reverse...
I think I get what the end result is supposed to be, with changing all the bits around and sending the modified code back. But why not let the PIC handle the bit changing after receiving a certain code or something along those lines.

OK. You're crazy!
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