mxgxw

Member Since: March 25, 2013

Country: El Salvador

  • I just recently installed one of those (not from Sparkfun but exactly the same KIT).

    Compared with the RAK831 this is indeed a more affordable KIT (Arount $100USD less). The RAK2245 is exactly the same as the RAK831 but with a small form-factor. and already includes a GPS unit.

    There is an issue however, with the small form-factor appears that RAK Wirelless didn't put too much attention to the design of the SPI traces on the Raspberry Pi Hat breakout. The original RAK831 KIT can support up to 4Mbps on the SPI bus, however on the RAK2245 it only supports 2Mbps on the bus. When you examine the code they use on the gateway you can verify that the patch applied to the lora-gateway library reduces the SPI speed.

    On my unit there were flux residues between the headers, I had to clean them up to be able to start the gateway without troubles.

    I would agree with the rest of the comments that only having the hat or even better only the 2245 gateway card could be a little bit better.

    I think it would be even better if you have all the items required to build a decent gateway for exteriors. Any IP55 cage, plus u.FL to N + Lightning Protection + 50Ohm cable + Exterior Antenna would be great.

    I can say once you put everything together the Gateway works great. We are getting 10 Km range with the one that we installed last week without trouble. Coverage map

  • If you are planning to use the Teensy->Fio board just remember that you'll need to cut the trace between VIN and VUSB at the bottom of the Teensy. If not, the 5V from the USB could get to the battery and you could damage the battery.

  • I designed something pretty similar last year, you can look at the PCB over OSHPark.org, in my case I tried to keep the footprint and the pinout from the FIO so it could be used as a drop-in replacement for the FIO v3.3, it also includes a LiPO charger.

    Click to open project in OSHPark

    I don't have a way to mass-produce it but is OpenHardware so I can provide the schematics and PCB layout if you wish to carry it out :)

    This is a picture how it looks like used in conjunction with a pretty BIG XB900HP with a SMA connector. (Taking it to the extreme)

    Teensy->FIO Translate board with XBEE900HP SMA -TOP-

    Teensy->FIO Translate board with -BOTTOM-

  • You are right, my wrong. In you put 4 them in parallel you are going to need at least 3.5v@2.8A, in series 12V@700mA would be enough as you said. Sadly I don't see a datasheet, may be he can put 3 of them in series and over-drive them a little bit (even reducing their lifetime if the he doesn't care).

  • If the forward voltage must be between 3.4-3.6V you can put them safely 4 of them on series, they are going to glow a little bit less but them are not going to require additional wiring. Just be sure that the 12V voltage source can provide at least 2.8A.

  • I think that the best library for using it with the Teensy is the SmartMatrix. I've just tried and it works great. Take a look a it: http://docs.pixelmatix.com/SmartMatrix/

  • Hi Mike! Here is the link for the translation to Spanish, also I have created an open Google Doc if someone wants to improve the translation. Regards, Mario.

    Hola a todos, les dejo el vínculo de la traducción de esta muy interesante y motivadora entrada en español:

    http://fuenteabierta.teubi.co/2013/12/los-pequenos-hackers.html

    Si piensan que la traducción se podría mejorar también les dejo el vínculo a un Google Doc abierto para que agreguen sus sugerencias:

    https://docs.google.com/document/d/1zUq3qTgwhUDCo7IW7rv9hTg_RY87WjfEC5t755SPF1s/edit?usp=sharing

  • Wow, this is a very good inspirational post. I could identify myself from the begining. Can I translate it to Spanish and share it on my blog? I think that many people here could like it :)

  • Programming on the Raspberry Pi is always really fun :)

    I've made something pretty simmilar at the beginning of this year. It's written on python I called it "rpitwit", it monitors your twitter account for a keyworkd and executes a command stored on a pre-defined directory.

    https://pypi.python.org/pypi/rpitwit/0.2.0

    The funny thing is that it comes pre-configured, ready to use and you can use python or bash scripts. The funny thing is that I wrote it for work with the Raspberry Pi but later I realized that it works on any Linux distribution with Python and PiPy :) I hope that you find it useful.