I had a chance to grab a few photos of the progress so far, also helps that most of my components that I had on order arrived today so the boards has been kitted out with all the headers.  Now I can plug the prototype personality in, still waiting on my crystals, switches, and diodes.

This gives an idea of size. (I don’t have big hands either)  This board has a 900MHz 2dB GSM SMA antenna, prototype personality board installed and battery holder for CR123A Lithium battery. 

Different battery options, using x2AA with a switched battery pack soldered onto the board.

The SMA connector is a standard PCB straight SMA connector that has been soldered onto the edge of the board.  The board have been designed for the Sparkfun PCB edge mounted SMA connector (SKU: WRL-00593), however I found that a standard PCB SMA connector will do the same job, the distance between the centre pin and the ground pins is the same thickness as the PCB and all the pins line up with the Sparkfun footprint, the centre pin fits perfectly and so do the two bottom ground pins, only difference is the two top ground pins don’t get soldered.

One of the LEDs flashing….Its Alive!!!!

Part 2 – RFM12 Hardware Interface

In this next part of the RFM12 tutorials I’ll be covering the hardware interface, signal descriptions and how you go about hooking it up to the MCU of your choice.

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As mentioned in my last entry I was toying with the idea of frequency hopping on the RF side of things, well looks like someone has implemented something similar here http://www.raccoonrezcats.com/rfmodem.html I’ll like to do something similar to this as it seems doable. 

While not able to get some “hands on” development time over the weekend, I did more reading of the HopeRF modules and these will be able to achieve the hopping, as the can programmed to any frequency in the 902-928Mhz Freq range so definately looking achievable.

If what the above links says on the site then we could (at least in theory) have a max output of 1watt if we chose to implement hopping, else we are limited to 1mW output power.