Mauried said:
Parts nos are ZW-3100, ZW-3102.
Low power 433 MHZ modules , data rate up to 10 kbs.
Just wondered what to drive them with just to implement a simple
remote controlled switch to turn on and off some solar powered water
solenoids.
First thing to know is you have to put a antenna on them of about 20cm. some
people just put the moddules in and wonder why they only go 10cm. so make
sure thats ok for what you want to do with them. The reciever seems to auto
lock somehow onto nothing and output rubbish, so its important that you send
a preample to give it time to adjust and then data and then CRC or parity
etc. if you are doing packet bursts. You can't just continously send a
contantly data value, it has a minimum bit rate and if you don't have enough
state changes it seems to wonder away from the frequency it has locked to
looking for data and ends up outputting rubbish again.
I made a on/off switch with no microcontroller at the RX by having the data
line add to the charge of a cap each time the output was positive. A
seperate really slow oscillator would then discharge the cap if not enough
high data bits were reieved in a certain amount of time. If the data cap got
charged high enough it would toggle a flip flop. So randomly I would
typically reicieve say 50% high and lows, so I set the thing to toggle over
if say 85% of bits within a certain time (say 0.5 seconds) where all high.
Then I would just send say 0x7FFF (93% bits high), which is enought to keep
it from wondering away. Haven't had it false trigger that I have seen anyway
:-D
just buy and stuff around with them they are only $10 each and lots of fun!