warp_be:
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I bought two transmitter/receiver ( so 2 rx and 2 tx) from seeedstudio.
It's written 433 on all 4 parts. They are meant to work together because they are sold together.
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The antenna is also connected. I read that i must use 300cm antenna, but also 17cm like on this post.
I don't know wich length is correct......if someone can help....
dear friend I bought the same 433 Mhz modules and tried them on a pic circuit they work very well, there is no
problem but the receiver and transmitter do not meet arduino.. finally ? decide to try the modules saperately
with an arduino transmitter and pic receiver / pic transmitter and arduino receiver...? will try that idea soon.
for the antenna question the antenna can be 17 cm it is because of the radio wave's wave lenght
it can be calculated like this
(wave lengt) = (speed of light) / (transmitter frequency)
and then
(antenna lenght) may be (wave lengt)/2 or (wave lengt)/4 or (wave lengt)/8 or (wave lengt)/16 .......
wave lenght (meter) = 310^8 (meter/sec) / 43310^6 (1/sec) = 0.6928 meter =69.28 cm
and also can be 69.82/2=34.64 cm , 69.82/4=17.32 cm ....