A new sensor in the house (Allegro A3214 Hall-Effect switch)

[Digit]

I've been testing a new sensor during the last 2 days, which I think is especially useful for Arduino fans who would like to build their own Door & Window sensors. The results so far are very promising! Check it out:

http://blog.hekkers.net/2010/12/04/the- ... ct-switch/

DSC_4717c_resize.jpg (46.72 KiB) Viewed 11511 times

[erisan500]

I use this exact same sensor to measure my gas consumption, way better then the CNY70 optical sensor that i was using before.

[Alexander]

Robert,

Three questions little related to this:
- The jeenode have multiple inputs. When 'door' sensors to be used, the price for a jeenode per sensor is ofcourse higher than using more of those sensors connected to one jeenode. What is your opinion about this. Would you use more of these sensors connected to a jeenode, a jeenode per sensor or a jeenode with multiple different sensors (like for in the same room also a temp., humidity, light, etc...) ? What is your installation at the moment?
- Are there smaller jeenodes (like less inputs?) ? If i look at the shop there is the JeeSMD also less price but i don't have the knowledge to answer the question myself at this time.
- Will you use all the jeenodes with the xbee modules? Or considering also to use the jeenode solution?

[Digit]

Alexander,

- The jeenode have multiple inputs. When 'door' sensors to be used, the price for a jeenode per sensor is ofcourse higher than using more of those sensors connected to one jeenode. What is your opinion about this. Would you use more of these sensors connected to a jeenode, a jeenode per sensor or a jeenode with multiple different sensors (like for in the same room also a temp., humidity, light, etc...) ? What is your installation at the moment?

I would certainly use more sensors per JeeNode if I can make all those sensors wake up the JeeNode from power down mode and be able to distinguish which sensor triggered this wake up. I have to look into that. The passage (dutch:overloop) would be the perfect place for 1 JeeNode for 4 doors!
And yes, if I can, I would also combine different types of sensors; all depends on the sensor need per location and whether it's technically possible to do so. Each sensor will be customized with those criteria in mind.

- Are there smaller jeenodes (like less inputs?) ? If i look at the shop there is the JeeSMD also less price but i don't have the knowledge to answer the question myself at this time.

The JeeSMD (http://cafe.jeelabs.net/lab/js2/) has the same amount of ports as a JeeNode (same number of ports), is smaller, however it doesn't have radio on board (but this can be connected IIRC). So to answer your question: Yes and No.

- Will you use all the jeenodes with the xbee modules? Or considering also to use the jeenode solution?

All the JeeNodes I have right now, also have XBees connected to them and they are doing fine; I see no need to introduce another RF medium.

BTW, think of this: this new sensor (or more) connected to a XBee... why not? There's no real "processing" or local communication (I2C for example) with the sensor, all you need is a digital input. I still have to look into things like the need for local debouncing, and the use of a "bare" XBee for this.

That's that "next step" I mentioned

[Alexander]

I would certainly use more sensors per JeeNode if I can make all those sensors wake up the JeeNode from power down mode and be able to distinguish which sensor triggered this wake up. I have to look into that. The passage (dutch:overloop) would be the perfect place for 1 JeeNode for 4 doors!
And yes, if I can, I would also combine different types of sensors; all depends on the sensor need per location and whether it's technically possible to do so. Each sensor will be customized with those criteria in mind.

"and be able to distinguish which sensor triggered this wake up"
That would be nice ofcourse, but you can send value/status of all the sensors when the JeeNode has been woken up? Not a nice situation ofcourse, but I would think this would be a nice to have?
I'm curious how you would see those sensors connected to the JeeNode. You would all those cables running through your room(s). What will be the impact of long wires? Like every cable has its resistence. Can you test this with for example this sensor? Or would you already have the answer (based on experience fe)?

The JeeSMD (http://cafe.jeelabs.net/lab/js2/) has the same amount of ports as a JeeNode (same number of ports), is smaller, however it doesn't have radio on board (but this can be connected IIRC). So to answer your question: Yes and No.

Okay, so the JeeSMD could be connected to a XBee modules? Is this on your list to do? I read you need a programmer for the chip. So more initial costs but lower cost on the "Jeenode" and smaller (less energy consumption?).

All the JeeNodes I have right now, also have XBees connected to them and they are
doing fine; I see no need to introduce another RF medium.

No i agree with you if you would do all those to be installed JeeNodes. I would prefer XBee cause of its technology, but it will cost also more. But like JC said in one of his blog posts: Maybe you would use the RF technology JeeNodes uses for sensors where a bi-directional signal isn't needed and use the XBee technology for switches or others (alarm etc).

BTW, think of this: this new sensor (or more) connected to a XBee... why not? There's no real "processing" or local communication (I2C for example) with the sensor, all you need is a digital input. I still have to look into things like the need for local debouncing, and the use of a "bare" XBee for this.

That's that "next step" I mentioned

[Digit]

"and be able to distinguish which sensor triggered this wake up"
That would be nice ofcourse, but you can send value/status of all the sensors when the JeeNode has been woken up?

I could, but I would rather not if I can; it's just the way I 'work'

Can you test this with for example this sensor?
Or would you already have the answer (based on experience fe)?

I'm going to that's for sure, before I install anything.

Okay, so the JeeSMD could be connected to a XBee modules? Is this on your list to do?

Not for now. Maybe I will, after examining some door frames, the available space etc.
If a JeeSMD is the better choice, well, then I will need one

I read you need a programmer for the chip.
So more initial costs but lower cost on the "Jeenode" and smaller (less energy consumption?).

I already have an ISP programmer, so additional costs have already been made (but not with the JeeSMD in mind).

But like JC said in one of his blog posts: Maybe you would use the RF technology JeeNodes uses for sensors where a bi-directional signal isn't
needed and use the XBee technology for switches or others (alarm etc).

I know, I'm spending more on wireless than I really need to; people always ask me why I chose this "weird" combination....

My choice wasn't based on writing down lists of pro's and con's, weighing the benefits of RF12 vs. XBee etc. etc.; none of that.
It's as simple as this: after the summer of '09 I wanted to do 2 things: get to know the Arduino and also the XBees. It didn't take long before I found out that I could combine these 2, so I did. With both RF12 modules as well as XBee you can create great things, I'm sure of that.

The primary thing that matters to me, is that it's all about having fun with what you do; some prefer PlayMobil over LEGO; I prefer XBee over RF12; that's just the way it is, nothing else

First thing I need to do right now is order some XBees, cause I'm out of stock right now!

[erisan500]

Robert,

looks like you becoming pretty experienced with XBee

Would an XBee module be able of having a temp,ldr,hall-effect,humidity and pir sensor connected to it where we could poll temp,ldr,humidity and auto transmit (event/interrupt) on the pir and hall-effect sensor? Reason I ask is because i'm looking for something smaller/cheaper then an arduino-xbee combination.

edit: To answer my own question, it seems possible when reading this thread: forums.digi.com/support/forum/viewthrea ... 8_offset,0

[Alexander]

That's a nice one. I thought it was basicly a send-receive device. So that would take out the JeeNode modules for our purposes (sensors)?

[erisan500]

Alexander,

looks like that. Will order a couple xbees, play around and keep you posted.

Eric

[Digit]

Guys,

Remember that you cannot write code and execute that on an XBee. So anything that is more complex than Analog Input or Digital Input is useless...
So forget about talking to (for example) a SHT11 by only using an Xbee. You'll need 'local' processing ability in that case.

Have you ever considered the Arduino FIO? http://arduino.cc/en/Main/ArduinoBoardFio
I'm ordering one to play with it; FF and things like wirelessly uploading/upgrading sketches are worth investigating

[erisan500]

There are also analog humidity sensors like this one: Honeywell HIH-5030

Brief specs:
Honeywell HIH-5030 "surface mount" humidity sensor.
Digikey Part # 480-3294-1-ND
Cost $11.23
Voltage range 2.7 -5.5V
Accuracy +-3% RH
Humidity Range 0 - 100 %RH
Output linear voltage --> VOUT=(VSUPPLY)(0.00636(sensor RH) + 0.1515), typical at 25 °C

Eric

[Digit]

Small update:

I tested with a solitary XBee (as in without ATmega) and this sensor; it works, I see samples coming in when the magnet is moved.
This is with the XBee always-on, more tests will follow.
But first I have to write some code, cause I don't support the ZigBee IO Data Sample Rx Indicator frame type in my system yet.