jpnorair

Member Since: July 9, 2011

Country: United States

  • Product WRL-00155 | about 2 months ago

    Every time a 433 MHz product is sold, there seems to be at least one AARL messenger saying that it can’t be used. Well, that’s dead wrong. I feel I need to build on a comment I made previously.

    1. In most of the world, it’s an ISM band. EU limit is 10mW. Some countries are higher.
    2. In USA, 420-470 can be used UNLICENSED via FCC Part 15.231 and 15.240. Granted, FCC wants you to use more like 1mW.
    3. Usage of ANY RF device sold on SparkFun should TECHNICALLY require you to obtain an FCC experimental license.

    Anyway, if you are operating this device away from any 70cm HAM stations, nobody is even going to know. Even if there is a HAM operator nearby, they blast so much power and need so much SNR that they still won’t likely notice. Furthermore, I’ve been building 434 SRD devices for years, I’ve never noticed much activity from HAMs inside the Region 1 434 ISM band, and I work in a place where there are a lot of HAM operators.

  • Product WRL-00155 | about a year ago

    “70cm” band covers 420-470 in USA. HAMs generally stay away from 433.05-434.79 ISM band. They have the rest of the 50 MHz (and technically you do too). That said, 10mW is too much radiated power even still, but no-one is going to find you.

    Based on the floorplan, looks like a CC1101 transceiver, BTW. Using that part at 10mW you should be able to get over 1km, at 9600bps, with a decent antenna. Especially if you hack it to use wideband FSK instead of narrowband as I assume is the case.

  • Product WRL-08482 | about a year ago

    Anyone interested in the part should try running a half-wave dipole. Monopole is going to be lousy with only a tiny ground plane.

    It’s an analog transmitter… to use with an embedded digital device it must have a DAC, or at least a tone generator of some kind. The simplest thing you could do on Arduino or similar board is to implement morse code that can be received on FM radio. Use a square wave near 500 Hz. That’s a pretty lame application, but analog systems tend to require more analog or relatively sophisticated digital. It would be easier to hook the damn thing directly to a turntable, for example, than it is to get a cool app out of an Arduino.

No public wish lists :(