epv

Member Since: January 26, 2008

Country: United States

  • Product WRL-08945 | about 4 years ago

    I bought a bunch of these and similar units. There seems to be a lot of variation in tuning. Some pairs work fine, other pairs barely at all. I wasn’t able to get a multi-transmitter set up working reliably, because I couldn’t find two transmitters and one receiver all tuned closely enough. (the transmitters alternate, they aren’t on at the same time)
    Note that the receivers seems to work by adjusting their gain to achieve an even DC balance, ie, 50% ones and 50% zeroes. So ideally you’d want to drive these with a dc-balanced coding like Manchester. Using them with a UART output sorta works but is not ideal. It improves things a lot if you try to structure your data to be nearly evenly balanced between zeroes and ones. One easy way is to send each byte followed by it’s complement which achieves DC balance at least on the per-character timescale, which is better than nothing and improves reliability somewhat. Of course it also halves your data rate.

  • Product LCD-08629 | about 4 years ago

    the connector on mine is also not glued. I thought i’d just solder right to the pins, which was easy, but it doesn’t work without physical pressure on the pins. I’ll probably just glue a piece of perfboard over it or something, as it looks funny with a clothespin on it.

No public wish lists :(