Hello to all,
I am using the Linx RXM & TXM LR (long range) modules. I was sending my data successfully until I change my qualifier to anything but 254. It operated very reliably with only an occasional hiccup (probably due to multipath around the metal buildings) at several hundred feet. I am sending an address (word) broken up into four pieces which is in bytes because I am using Manchester Encoding, then reconstructing and comparing the address in the receiver (constant) and also doing the same with the actual button pressed on the transmitter (key). I am not using USART because I still don't understand it after reading countless post on this forum and reading the datasheet.
So I am doing this on the transmitter:
serout2 serpin,16468,[$AA,$AA,$AA,$AA,$AA,synch,addA,addB,addC,addD,addA ,_
addB,addC,addD,key,key,key,key,key]

And this of course on the receiver:
SERIN2 serpin,16468,500,loop1,[wait(254),address1,address2,address3,address4,_
address5,address6,address7,address8,mydata1,mydata 2,mydata3,mydata4,mydata5]


Then I am decoding the address (manchester) then summing those up, ADD1=ADDA+ADDB<<4+ADDC<<8+ADDD<<12
comparing my address (constant) in the receiver to ADD1
then I check:
IF (address = add1) && (mydata1 == mydata2) && (mydata1 == mydata3) &&_
(mydata1 == mydata4) && (mydata1 == mydata5) && _
(MYDATA1 > 0) && (MYDATA2 > 0) && (MYDATA3 > 0) && (MYDATA4 > 0)&& _
(MYDATA5 > 0) THEN
Index2 = 1
For Index = 0 to 3
mydata.0[Index] = mydata1.0[Index2]
Index2 = Index2 + 2
Next Index
chksum2 = chksum2 + 1
chksum3 = 0
high rf
else
chksum2 = 0
chksum3 = chksum3 + 1
low rf
endif
if chksum2 >=3 then start
until chksum3 >= 1
ADD1=0
chksum2 = 0
chksum3 = 0
mydata = 0
I decode the mydata
then i repeat this three times by going back up to the SERIN2
using that if statement ,if chksum2 >=3 then start
then I assume all of mydata and the address match is good so I continue on to the output I want on.

Life seems good because each output is actually staying on as long as I am pressing the button on the transmitter and the output immediately goes off as soon as I release the button.

BUT:
It does not work if I change the qualifier to anything else, maybe this should not alarm me but I have been trying to figure out why.. call me a perfectionist,...after all I am sending a preamble to balance the data slicer,...right? And I have tried sending more $AA's and even $55's and a combination of those. I am aware of the rx module "noise" read many post on this forum,watched it on my scope and squelch is useless because of range limitations but mainly to stop the noise completey, squelch turn up full, no data is then received

ok, other than changing the qualifier this remote control works almost perfect, that may be an over statement . I have learned a lot from all of you out there, especially breaking down my code and understanding how it ticks.

After doing a search on checksums, found many articles about CRC and a dead link PDF about CRC but as I mentioned, it is a dead link. So any suggestions, preferably in lamen's terms how I can use CRC?

Many Thanks