Receiver (startup) timing issues, 433MHz module

Discussion in 'Wireless & RF Design' started by xtoffer, Oct 3, 2013.

  1. xtoffer

    Thread Starter New Member

    Sep 30, 2013

    I find myself looking for some insight.. and as I often end up in this forum when googleing I thought I'd give it a shot :)

    I got a cheap transmitter/receiver module pair (link), however with minimal documentation (link). I wanted to implement some "low power listening" technique on the receiver side for power saving reasons. However, this requires me to turn the receiver on and off very quickly and this is where the issues are at the moment.

    By my estimations (and code timings that work) it takes this receiver module at least 250ms to turn on and synchronise to my "preamble" (which is too slow for the response time I want). Since I failed to find any good information on the turn on time I then got another receiver module (link) with datasheet (link). According to the datasheet this one has a 3ms turn on time if I read it correctly. However by my estimations it takes this one about 1s to turn on and synchronise. (Or at least still a very long time, relatively speaking).

    Can also mention that when the receiver is kept on and the transmitting circuit (or transmitting module) is switched off/on the synchronising is "instant" (~35ms including transmitter turnon).

    So this is where I am looking for answers. Gonna throw some questions out..

    Why does it take so long?
    What are normal startup times for these kinds of receivers?
    I know that there is some kind of signal strength adjusting going on in them, how long does that take? And can it be the reason for the delay?
    Is the number in the datasheet wrong or did I misunderstand it?

    Thanks in advance for any insight :)
    (Electronics is a new hobby of mine so still very new to this field and RF technology in particular.)