Data logging help: Zigbee?

[Vizier87]

Hi guys,

I'm monitoring at least eight ADC data from my sensor network, and I'm transmitting them using those noisy 315 MHz RF modules, (which of course will need to be replaced) to another PIC, USB-connected to a PC for data calibration.

Most of my works are always concentrated on analog electronics, so my PIC knowledge is pretty basic.

After Googling for Zigbee modules, I'd just have to ask since my knowledge on Zigbees are only a follow-up from UBWs, which is pretty limited and certainly not for RF communications.

So... which Zigbee module best suits these requirements:

1: REAL TIME data monitoring (For a PIC's ADC data), as real as talking on cellphones or nearly as good is okay (the best I could put it )
2. Range of RF transmission: around 500 metres (not that important)
3. USB connected to a PC.

Or are there better wireless data-logging modules?

Cheers,
Vizier87

 

[3v0]

What Zigbee has to offer is a standard which allows devices from various vendors to work together. It has baggage you do not need that drives memory requirements up and increased complexity. I had to read the Microchip Zigbee documentation a few times to get a handle on it.

Zigbee is based on IEEE 802.15.4-2006.

Another network based on the same physical standard is MiWi.

MiWi™ and MiWi P2P are proprietary protocol stacks developed by Microchip for short-range wireless networking applications based on the IEEE 802.15.4™ wireless personal area network (WPAN) specification. The MiWi protocol stacks are optimized for low-power, low data rate, cost sensitive application and offer a small foot-print alternative to the standard based ZigBee® compliant protocol stack.

 

[DirtyLude]

He's not implementing the protocol, he just wants an RF module and the most common ones are the Zigbee ones, like the XBee's. Yes, Zigbee itself is an overcomplicated mess, but the protocol itself is hidden from you unless you are actually trying to implement the stack yourself.

I don't have any experience with these modules, but I would think you could just go on Sparkfun and find whatever module looks best. The data that it sounds like you are sending doesn't sound like it requires a very high bit rate.

 

[3v0]

There are many non Zigbee modules out there. Like this one that you can get at digikey for about $6. Datasheet

I do not see what your gripe is with my post. I told him what he needed to know and I have experience with Zigbee.

 

[DirtyLude]

I do not see what your gripe is with my post. I told him what he needed to know and I have experience with Zigbee.

He is asking about a standard Zigbee module, which is a wholly self contained unit which does everything. In that case the complexity of Zigbee is a moot point. You just talk over the UART and get the data on the other side. I think you are confusing a Zigbee module with a IEEE 802.15.4-2006 compliant module like an MRF24j40 where you can implement Zigbee of MiWi on the uC.

Yes, there are other options, but the range requested means you might as well get an XBee since the extended range modules are fairly expensive and then you have to implement the protocol on your own.

 

[3v0]

There are ZigBee modules that require a stack run on your micro controller. I did not want him going there.

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[Vizier87]

Thanks guys. I'm gonna explore the links in a mo.

 

[DirtyLude]

There are ZigBee modules that require a stack run on your micro controller. I did not want him going there.

Those are IEEE 802.15.4-2006 compliant transceivers. Yes, I've had experience with those too, the MRF24J40 and the CC2500.

If you want to use a transceiver and implement the protocol yourself (not Zigbee, but a simple P2P), I would suggest the RFM12BP. Futurlec is the only one that sells it retail that I know of. It's a high powered version of the RFM12B, which I have experience with. Not as complicated as a 802.15.4 compliant transceiver, but much more useful than those basic radio modules. The high powered BP version requires 12V supply as well as 3.3V supply though, which is a pain.

Otherwise the XBee modules are super simple, can be high powered, pretty much guaranteed to work right out of the box, and certified.

 

[3v0]

I agree.......

 

[Vizier87]

I'm getting there guys... I'm getting there. So if I buy **broken link removed**, and build the logic level shifting circuit like this then I'm set, ain't I? How about the part where the uC holding the eight ADC data? If I'm using UART, does that mean I have to buy another Xbee for the M2M application?

Many thanks.

 

[DirtyLude]

There's some talk about whether the XBee's I/O is 5V tolerant. It uses a SAM7 uC, which has 5V tolerant IO, so the level shifters should not be necessary, you just need 3.3V for the power.

The Sparkfun adapter board just uses a single diode for a bit of voltage drop on the DIN line.
SparkFun Electronics - XBee Explorer Regulated

 

[Vizier87]

Just to be sure, so it can be wired up to uCs directly for UART support, right? This is how I understood it:
**broken link removed**

Am I right?

 

[DirtyLude]

Read the user manual.

You will need a UART<->USB interface to connect it to the PC over USB.

Sparkfun has a breakout board with the interface built in.
https://www.sparkfun.com/commerce/product_info.php?products_id=8687

 

[Vizier87]

Ok thanks dude. I'll be perusing the rest.