Adafruit 440/900mhz boards?

Discussion in 'RFinderPi - Open Source radio interface based on R' started by K3RW, Sep 5, 2016.

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  1. K3RW

    K3RW Ham Member QRZ Page

    I came across these boards looking at the Adafruit website.

    https://www.adafruit.com/products/3...0NAaB1MeYm9HQAHBnZ0D3M9cIF8oHHQbwUaAijl8P8HAQ

    (Hopefully the link works... if not, Adafruit calls it a LoRa Featherwing. There is a 900mhz and 432mhz version)

    What could these be used for? My first thought was to use them as a repeater, a receiver, etc. I haven't got a clue about their software but perhaps it gives a clue about what mode(s) could be used... FM, SSB, etc.

    It looks like they can be dynamically tuned up and down the spectrum a bit.

    I dunno if these have any ham use. 900mhz equipment is hard to find.

    Here is another one.

    https://www.adafruit.com/products/3071

    They call this a radio breakout board. This particular one is 432 also. There is another one more similar to the Featherwings that says it is 'packet radio', but I'm not sure if it is a different term than what I thought packet radio is... the older mode, I mean

    Sorry if these aren't R Pi capable... not sure how to tell. I'm still learning about the R Pis.
     
  2. KK4NSF

    KK4NSF Ham Member QRZ Page

    I've been looking at those and it does appear that they are compatible with any data stream..... so they would be compatible for a Pi to Pi link.

    They would be VERY handy for creating private networks that would be "off the net".
     
  3. K3RW

    K3RW Ham Member QRZ Page

    Would they be compatible to send/receive a SSB, CW, or other type of ham signal?

    I'd love to buy one of these and find out, but my programming skills are nil and I pretty much have to copy/paste what everyone else writes. I don't have enough knowledge of coding to do more than that.
     
  4. KK4NSF

    KK4NSF Ham Member QRZ Page

    since they are designed for FSK, they wouldn't work for SSB voice transmissions. They would work for CW, but you'd have to work out how to properly key it using your Arduino / Pi. If I were going to use one, I'd use it as intended: for sending data packets to and from a Pi or other computer. If I wanted to do CW, I'd get one of the low-cost transceivers and use the Pi as a keyer/ reader.
     
    K3RW likes this.
  5. KK6YAE

    KK6YAE Ham Member QRZ Page

    I have a secret dream of putting pi3's up on every mountain top in town using small solar panels/weather proof enclosures, and linking them using the 900mhz lora board/radio shield. I'd like to create a ham only SMS service that could be accessed by any ham with a pi/lora setup. It would work quite well, and be extremely easy to expand/access. Problem is I can't write code well enough to really pull it off. (Yet) It would be like the mesh stuff hams are doing now, but 1000 times more affordable, and omni directional, with more range, and serve more purpose. The silly thing about the mesh nodes is, you can't communicate over them at all, because there's no one standardizing any services that are typical and there waiting for people to link up. With Lora, you write a simple texting program that broadcasts to all the nodes within range, and people text/ID. Actual communications, just like voice comms (but text). The protocol has a -134dBm receive sensitivity and there are youtube videos of 130+ km links being pulled off from mountain tops. Pretty neat stuff! Maybe I'm just dreaming.

    https://www.cooking-hacks.com/docum...le-shield-arduino-raspberry-pi-intel-galileo/
     
    KC3BZJ and K2GOG like this.
  6. NC5P

    NC5P Ham Member QRZ Page

    These may well become a good digital voice platform eventually. You should be able to run D-Star, DMR, P25, and Fusion but not analog. For 440 all those modes are used, but on 900 only DMR and P25 are available on radios. There are 900 digital radios for sale used but not a lot new. I see quite a number of Motorola XTL2500, XTS2500, EF Johnson 5100 for P25 and XPR4580 and XPR6580 for DMR. I purchased a 5100 for $140 a year ago (they have gone for as little as $40 in the past). There should be some offerings from other companies as well for DMR but some may not be easy to program into the ham band. These just require hex editing to make them work, no hardware mods needed.
     
  7. AD5MB

    AD5MB Ham Member QRZ Page

    the 433 MHz radios are called LDP in Europe and available to everyone:

    https://en.wikipedia.org/wiki/LPD433

    In the states they are theoretically limited to licensed amateurs only

    The 900 MHz radios are in an ISM band in the US, but the 33 CM band is verboten in central NM where I live. I called the FCC enforcement bureau and asked about these radios. The lady who answered said they are covered under Part 15 ( no indication on the radios or packaging that they are Part 15 certified ) and got quite stressed out when I continued to ask questions.

    I believe that they are neither specifically permitted nor denied, just overlooked because they have not been brought to their attention.

    It is very common to find 433 MHz TX modules with connectors labeled VCC, GND and ATAD. Someone spelled DATA backwards, people clone the misspelling, it will probably continue for decades.

    There is a more powerful 433 MHz module called the SI4463 Wireless Transmission Module that appears to have parallel GPIO pins and function as a UART:

    http://www.icstation.com/433mhz-si4...sion-module-10mnw-wireless-serial-p-4622.html

    I have a set of the cheap ones and a SI4463 based module on the way. I am working on remote motion sensors around the periphery of the property, possibly having the sensors call in using DTMF tones. ranges from 400 feet to a quarter mile. At this time we are in the all talk no do stage.

    Breakout board is a generic term for a board that supports an IC or a module that does not work well with breadboards. note the difference between

    https://www.sparkfun.com/products/10680

    and

    https://www.sparkfun.com/products/13699

    Those Adafruit breakouts let you use a module with SMD pins, that needs external supporting chips, without having to mess with SMD.

    They are compatible with RPi and Arduino. First thing to know about RPi VS Arduino: RPi goes brain dead while doing housekeeping; cleaning out unused variables, closing files, so they are not good for things that are time critical like logging the time a motion sensor activates or stopping a robot before it drives off a cliff. Use Arduino et al for time critical applications.
     
    Last edited: May 8, 2017
    KC3BZJ likes this.
  8. K3RW

    K3RW Ham Member QRZ Page

    Thanks! Great info.

    You can't use 900mhz in central NM? I've got a 900mhz ATV transmitter and receiver--but the last 900mhz ATV group here disbanded a while back. I knew about some of the 70cm restrictions up near the Canada border but didn't know about that one.
     
  9. AD5MB

    AD5MB Ham Member QRZ Page

    900 MHz is used at White Sands Missile Range. It is best for all if I do not go into detail. Oversimplified bottom line: No 33 CM south of a line through Mountainair.
     
    K3RW likes this.
  10. N4AAB

    N4AAB Ham Member QRZ Page

    Ah, I had noticed their Featherwings but since I am low on cash didn't look into what they are for. Interesting.
     

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