Repurposing AirWick FreshMatic as JeeNode

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Repurposing AirWick FreshMatic as JeeNode

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skobalczyk

In case you haven't seen it, AirWick FreshMatic is a small device to automatically spray the air refreshner on given time interval. Recently I came across another version that also has a motion sensor built in, and I though it would be good source to get a motion sensor. Since it was on sale for around 10 Euro I bought one.

When I took it apart I found a nice, big DC motor and two connected boards: one with the microcontroller and second with the motion sensor and green LED. I found that the motion sensor board sends the signal to the controller by pulling one of the output pins LOW. So it can be easily cought using interupt on Arduino.

Now it occured to me that I could use not only the sensor but also repurpose the whole box to host the JeeNode and other sensors. Since I don't have JeeNode yet, I used full size arduino and pair of Xbees, but it all fits nicely inside the box. I also added a temperature sensor (D18B20) and a photoresistor. I had to modify the Room sketch a bit to use my motion sensor and report via serial instead of RF18.

Here you can see few photos on how it came together:
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics

So I'm happy to report that first node of my network is already on duty and reporting data. And I already have another AirWick waiting to host the JeeNode :-)

Please let me know what you think.

Posted 13/09/2009 17:13:18
jcw

Love it! Yeay for hardware modding :)

Posted 13/09/2009 17:25:53
seaton

I love it! now to see if they sell them here in Australia!

Posted 14/09/2009 03:38:42
skobalczyk

I'm glad that you like it :-)

I've uploaded few new photos from taking apart the AirWick mini.
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/P1140071.jpg

This time all electronics are on one board, but layout looks similar so I just need to cut few traces and attach wires. After removing the refresher can there is lots of room inside to put the JeeNode with plugs.
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/P1140086.jpg

AirWick is powered from 3xAA batteries. Would this be sufficent for the JeeNode? How should I attach batteries to JeeNode?

I would also like to use the two switches that it has on the front. Maybe first as an on-off switch and second to select repororting interval (for example 1 minute, 5 minute, 10 minutes). Can you help me figure out how to attach so many wires to DIO?

Posted 16/09/2009 08:45:48
jcw

Yes, 3xAA or AAA is fine. As for how to attach them - see tomorrow's weblog post ;)

One low-cost way to attach multiple buttons to a single pin is to use a resistance divider and read out the value on AIO. More elaborate would be to use an I2C expander chip such as the MCP23008 or MCP23016 - but this requires 2 pins to connect via a bit-banged I2C bus.

Posted 16/09/2009 12:19:41
skobalczyk

Thanks for the info. I will also try to follow your tips on Lighty to reduce power consumption. Is there a way to measure battery status/voltage? I would like to include it in the report so I can setup alert when any of the nodes runs out of power.

I think I will try to do it with I2C chip if I can get one. Good oportunity to learn how they work :-)

Posted 16/09/2009 12:26:27
skobalczyk

Hi,
I've managed to find out how to attach wires to the PIR sensor on the Mini version board (I will post some pics later). But I don't know how to catch the interrupt on the JeeNode.

On the Arduino board I connected it to digital pin 2 and used this function:

attachInterrupt(0, motionDetected, LOW);

On JeeNode I connected it to the last pin of the plug described as IRQ, but I can't figure out how can I attach to it. I tried passing different values to attachInterupt function but none is working as expected.

Posted 18/09/2009 07:56:25
jcw

For something as slowly changing as a PIR sensor, I'd simply use polling - in loop() test for the state and call your routine when motion is detected.

For low-power use, interrupts could be used, but again, a quick poll every 100 ms or so is probably enough. That means you can simply put the MPU to sleep and poll as before.

Interrupts can be complex (so can real low-power coding be, btw). It'd stay away from them for anything with less than say 1 ms real-time requirements. Here is some info on interrupts if you insist ;)

http://www.nongnu.org/avr-libc/user-manual/groupavrinterrupts.html

[i]Be prepared to delve into exclusive access, volatile variables, and race conditions...[/i]

Posted 18/09/2009 10:36:24
jcw

Btw, the IRQ pin is shared between all ports and attached to digital pin 3, i.e. "attachInterrupt(1, ...)".

Posted 18/09/2009 14:21:00
seaton

I just found these down here in Australia, ~$AUD9 so have bought one to sacrifice to the sensor gods!

For those looking for them Australia just go to your local Woolworths (and I assume coles) and check out the cleaning isle. There appear to be two different versions, a larger one and the mini. the mini is the cheaper of the two.

Posted 28/10/2009 06:51:51
skobalczyk

Hello Seaton,

I switched to the mini version myself, and JeeNode fits perfectly inside. You can see this on last few photos in my gallery
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/P1140082.jpg

I will try to post some more photos today to show how I cut the traces on the board.
In fact I already have three more waiting for modding :-)

Let me know if you have any questions or ideas.

Posted 28/10/2009 07:06:32
seaton

@skobalczyk

what traces did you cut to get the motion signal on the board?

thanks,

Stephen..

Posted 28/10/2009 07:09:12
skobalczyk

Stephen,
Here is a quick photo of the board:
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/board.jpg

Red lines indicate the traces that I cut to prevent powering the original microcontroller. Green arrows show where I attached the wires from JeePlug. Click on the image for larger version.

Hope this helps!
Szymon

Posted 28/10/2009 07:32:18
skobalczyk

Here is one more photo that shows how all this fits inside:
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/P1140383.jpg

I cut the top of the spray carnister holder so that there is easy access to the JeeNode. The right JeePlug has SHT15 temperature/humidity sensor and a LDR attached. The LDR is on the wire so it sticks out through the hole where spray tip would normally be. The left JeePlug is the one attached to the board. JeeNode is powered from the original 3xAA batteries - notice the red socket under capacitor on the left but you can solder the wires directly too.

Posted 28/10/2009 07:43:43
seaton

Many thanks Szymon

that's a big help :)

Stephen

Posted 28/10/2009 12:48:19
skobalczyk

No problem. I will try to send you my room sketch later as well.

Posted 28/10/2009 12:53:51
andras

@skobalczyk - Great enclosure ! I missed this topic earlier, but I followed the link from jc's today's blog to get here. I immediately bought myself one today in the local supermarket (AH) for only 8 euro's and followed your trace cutting instructions; it looks like it works well. One note: the PIR and LED arrow-labels in the photo seem to be switched.

Could you please post your sketch in the wiki area ? I would love to get this working with my jeenode.

Posted 23/01/2010 21:41:07
skobalczyk

@andras - glad that it works for you. And you are right about the PIR and LED arrows - it should be reversed.

I'm afraid I need ask jcw to create wiki account for me first. So in the meantime you can download my sketch here:
http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Blog/Room%5EMini.zip

It's based on the Room sketch with some small adjustment. You can use either the DS18B20 or SHT11 temperature sensor. Note that it uses the power saving code but I haven't applied the latest changes that jcw posted last week. Still one of my 4 nodes is still running on same batteries since 23 Dec :-)

Posted 23/01/2010 21:56:50
andras

Thanks, I'm gonna try it our. BTW: I measured the current drawn by the repurposed Airwick board; it was about 40-50 micro amps, so quite doable.

Posted 24/01/2010 21:49:57
skobalczyk

Thanks for reporting your progress. Can you also measure the overall current draw with my sketch? We could compare it with the values reported by jcw in his recent posts.

Posted 25/01/2010 06:52:52
michelvd

@andras, do you mean Albert Heijn with AH as local supermarket ? And if so, where do you live because I an't seem to find the right Airwicks here in my town. I've got one now, got it via Ebay :)

Posted 25/01/2010 07:59:21
skobalczyk

@michelvd I see plenty of them in my supermarket (Krakow, Poland) for around 6-7 Euro.

Posted 25/01/2010 08:01:35
michelvd

@skobalczyk : I can't find them in Wijk bij Duurstede (Netherlands, 15km from JeeLabs ;) ).
But I'll have a look in Houten tomorrow where I work.

Posted 25/01/2010 09:58:36
jcw

Hey, Michel - you're welcome to drop by! I'd also be interested to hear whether AH Houten has them, haven't checked yet.

Posted 25/01/2010 10:20:34
michelvd

Well, today the AH had them. Turns out they were getting rid of the models without sensor first ;) I got one for now, just get the thing to work first :)

@jcw I'll have a look for you if I'm in the AH Houten tomorrow.

Posted 25/01/2010 18:40:44
adamfred

I've ordered two and I wasn't even looking at motion sensing. Repurposing is too cool, I can't resist. They are $10aud here.

Posted 26/01/2010 07:43:53
andras

@michelvd - You already found it now, but yes I meant the Albert Heijn (Berkel en Rodenrijs, 60km from JeeLabs).
@skobalczyk - I fear I'm underequipt to measure the average current drawn with the entire sketch like jcw did. I only have a simple multimeter (gotta get myself one of those usb scopes one day :)

Posted 26/01/2010 11:39:33
rubi

@skobalczyk

Awesome enclosure for room nodes, thank you!

Cheers
Rubi

Posted 04/02/2010 09:12:28
andras

I made 2 FreshMatic Rooms nodes. I have some pictures also. For those interested, you can take a look at them here:

www.tucsni.nl/jee

I used JeeNodes with the rooms board (/w DS18B20), so my setup and the sketch I used are a bit different than that of Szymon. I slighly modified JCW's rooms sketch for my situation. You can get the sketch from the above mentioned site.

Posted 10/02/2010 15:01:39
jcw

Wow, now I gotta try and find some Airwicks :)

Posted 10/02/2010 15:23:57
weylan

Andras,

I was wondering if you can post some more about using the DS18s20? Maybe some simple code, but some more closeups of what you did and how you got the Jeenode to work with this? I am very interested in doing this exactly.

I can handle the software, but I could use some more hardware help here?

Posted 17/02/2010 18:37:03
sysrun

Should the Lens be removed as shown on this Pic: http://cid-4c7ec0c2176a0b0d.skydrive.live.com/self.aspx/Environmental%20electronics/P1130973.jpg#resId/4C7EC0C2176A0B0D!2919
?

Posted 23/04/2010 16:39:13
kintel

The lens is necessary. It's a fresnel lens for increasing the field of view.

Posted 23/04/2010 17:40:31