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Topic: Reduced board for measuring (Read 1 time) previous topic - next topic

mdo

Hi,

I've now played around with my Arduino for some time and of course this thing is a great platform. I'm using it for measuring some temperature and upload the values to a server that stores them in a RRD database for graphing.

I plan to use a couple of devices to accomplish these simple telemetry jobs in different places of the house. They shall communicate via non-wireless TCP/IP network at best -- but that's no knock out.

While the Arduino is a terrific device, the costs sum up quite much when I think of buying X Arduinos with an ethernet shield.

So my simple question: can anyone recommend a "limited edition" with networking that is available at a cheaper price?

Best regards
mdo


Grumpy_Mike

The arduino itself is fairly "limited" with not much to cut at. You can always get the cut down version, the one without a USB/ Serial bridge chip but then you do have to talk to it to program it. You can take this "off board" and just use a pin header on each device.
Your best bet would probably be to combine the Ethernet chip and processor on one board made on strip board or custom PCB.

GordonEndersby



How about the all in one arduino and wireless ethernet board from asynclabs.
The yellowjacket http://asynclabs.com/store?page=shop.product_details&flypage=flypage.tpl&product_id=24&category_id=11

Ive got one to play with and its tiny.

Gordon

mdo


> How about the all in one arduino and wireless ethernet board from asynclabs.

The YellowJacket looks pretty nice. But I don't really need wireless and I assume that non-wireless connectivity is cheaper.

I don't want to argue the 55 USD it costs but for my purpose I don't want to spend this much.


> Your best bet would probably be to combine the Ethernet chip and processor on one board made on strip board or custom PCB.

Poor me, while being able to handle a soldering iron I fear to have not enough knowledge to build some custom design.


Anyway thanks for the input!
mdo


niels.brouwers

Have you considered getting an STM32 board? They're relatively cheap for what you get in terms of ram, program flash, and I/O (although all you'll be doing is reading values from an ADC or I2C and sending it 'home'):

http://cgi.ebay.co.uk/USB-SD-Ethernet-Enchanced-STM32-F103-STM32F103-Dev-pack-/220628088949?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item335e757875#ht_2421wt_932

They're approximately $36 a pop and have a built-in Ethernet controller and excellent tool-chain support (GCC).

Alternatively you could try and get a couple of wireless sensor nodes. I like the mc13224v-based redbee motes:

http://redwirellc.com/store/index.php?route=product/product&product_id=56
http://redwirellc.com/store/index.php?route=product/product&product_id=53

They are $43, but you get a nice, small form factor, wireless solution. Open source code examples available here:

http://mc1322x.devl.org/

The advantage of wireless is that they are non-intrusive, and you can set up a multi-hop network easily (i.e. using contiki: http://www.sics.se/contiki/) and you can power them with two AA batteries.

Finally, if you're going to run wires anyway, why use Ethernet at all sampling points? You can hook up multiple I2C temperature sensors to a single microcontroller, and just run the I2C wires instead of UTP. Alternatively you can have a single MCU at each sampling point (for example a http://www.pjrc.com/teensy/ or some other inexpensive little board) and connect them with low-speed I2C. Then, have only one of them interface with your server over TCP if you wish. Not sure if I2C is good over long lengths of wire, but there must be other interconnects that you could use. The idea is that you can simply build a minimum spanning tree and do simple store-and-forward networking to get data packets to the sink node (the one connected to the wired network).






lefstin

#6
Jul 31, 2010, 09:06 pm Last Edit: Jul 31, 2010, 09:07 pm by lefstin Reason: 1
If you're willing to go wireless (and write your own protocol), the JeeNodes are very affordable.  They were designed with in-home telemetry in mind.

http://cafe.jeelabs.net/lab/jn4/

The U.S. version is available at Modern Device for ~ $20:

http://www.moderndevice.com/products/jeenode-kit

ill_switch

#7
Aug 02, 2010, 05:50 pm Last Edit: Aug 02, 2010, 05:50 pm by ill_switch Reason: 1
Maybe I'm missing something, but if your goal is to get sensor data from several places in the house, why do you need several microprocessors? Especially if you're already resigned to running wires.

Why not just use a single Arduino and Ethernet shield, plus a bunch of One Wire sensors, for instance?

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