Raspberry Pi and Wireless Sensor

Nice Pi project, Simon.  It sounds like a very effective way of hooking up micros to remote sensors.

And I'm impressed by Ciseco's low prices, which seem to fit the Pi niche well.  Hopefully this kind of pricing will attract school kids into doing some experimentation.

Could you say something about the RF side of things please, ie. standards, band used, channels if any, power, encryption, etc.  I assume "XRF" uses Xbee because you said "X-Bee shaped socket", but there seem to be a range of things covered by that name according to Wikipedia --- http://en.wikipedia.org/wiki/XBee .

Although such devices presumably use unlicensed spectrum, it would be good to know the exact details and encourage good practice to avoid interference.

Hello Simon,

Thank you for this, I started off the original thread that you posted a link to this in :-)

By happy coincidence I already have one of the Ciseco Slice of Pi shields, so I think I need to get my self into gear and get it soldered up.

I've only bought a couple of bits from Ciseco so far, but they seem pretty good and also have good customer service from my experience, so more power to them too.

Steve

XBee is altogether much more complicated, but it does have a nice socket layout with Tx, Rx and power. The XRF modules just use these. They aren't XBee. Have a look at Ciseco's website for full specs of their devices. They sell all sorts of cool stuff.

BTW. I have no link to Ciseco, other than they lent me some things to play with and I like their products.

Thanks Simon, I looked around a bit further after you said it's not Xbee.

Both OpenMicros and Ciseco seem pretty reticent to identify exactly where their boards fit into the RF regulatory framework.  However, their XRF radios all seem to use the CC1110/1111F32 device from Texas Instruments, datasheet here --- http://www.ti.com/lit/ds/symlink/cc1110f32.pdf --- and TI are more usefully informative.

13.18.1 SRD/ISM Regulations

International regulations and national laws

regulate the use of radio receivers and

transmitters. Short Range Devices (SRDs) for

license free operation below 1 GHz are usually

operated in the 315 MHz, 433 MHz, 868 MHz

or 915 MHz frequency bands. The

CC1110Fx/CC1111Fx is specifically designed for

such use with its 300 - 348 MHz, 391 - 464

MHz, and 782 - 928 MHz operating ranges.

The most important regulations when using the

CC1110Fx/CC1111Fx in the 433 MHz, 868 MHz, or

915 MHz frequency bands are EN 300 220

(Europe) and FCC CFR47 part 15 (USA). A

summary of the most important aspects of

these regulations can be found in [10] or [11].

 

[10] AN001 SRD regulations for license free transceiver operation(swra090.pdf)

[11] ISM-Band and Short Range Device Regulatory Compliance Overview (swra048.pdf)

That's a start.

Some links relevant to those standards:

• TI's references:   [10] http://www.ti.com/lit/an/swra090/swra090.pdf , [11] http://www.ti.com/lit/an/swra048/swra048.pdf
• UK:  http://stakeholders.ofcom.org.uk/spectrum/spectrum-management/licence-exempt-radio-use/licence-exempt-devices/short-range-devices-information
• EU:  http://www.rfm.com/company/etsi.pdf , http://www.etsi.org/website/technologies/shortrangedevices.aspx .
• US:  http://en.wikipedia.org/wiki/Title_47_CFR_Part_15 , http://en.wikipedia.org/wiki/Short_range_device