iRobot Roomba

Integrating this robot into my Domotica system is a good example of how easy it can be to integrate a new type of Device into a Domotica system that works and is built like i think it should

Do i want to use the iRobot remote control? No, of course not; those things can get lost and it doesn’t bring integration! I have an IRTrans for Infrared controlled devices. So the first thing to do was finding the right IR codes for the Roomba. That wasn’t too hard. I created a .rem file for the IRTrans server and saw I could give the Roomba the CLEAN command.

Actually, that was the hardest part. Next thing I did was add a button on the touchscreen in the livingroom to manually control the Roomba from there. Drag & drop a button, a combobox and write 1 line of VB code:

Touchscreen finished; next! My Domotica system. This one needed a restart cause i had to add a new Device Class:

unit Roomba563;

interface

uses
 IRControlledDevice;

type
 TRoomba563 = class(TIRControlledDevice)
   constructor Create(const AAddress,AphDeviceID,ALocation,ADescription:String); override;
 end;

implementation

uses
 Windows, Utils,
 DeviceTypes;

constructor TRoomba563.Create;
begin
  inherited Create(AAddress, APHDeviceID, ALocation, ADescription);
  SubDelay:=100; //msec
end;

initialization

 OutputDebugString('Init Unit Roomba563');
 gclDeviceClasses.Add(TRoomba563);

end.

Copy, Paste, Replace All, Save, Compile, Done! Virtually no “real” additional code needed, no adjustments to existing code; it all works perfectly together. It’s just another type of device…

Now, this Roomba makes too much noise to have it driving around in the same room as where you are, so there are 2 options: let the Roomba do the cleaning at night or while everybody’s away.

So now I’ve got one thing left to do: create 2 new events so that a status change of the alarm system will trigger either a CLEAN or a DOCK command, so that the Roomba will start cleaning while we’re away but also obediently return to its base station when we get back home. That’s about 6 records (rows) that need to be added to the database.

Done!  I love it when a plan comes together

ELV PIR13: PCB 25 x 37 mm, 13 mm PIR

I’ve ordered a couple of these ELV PIR13′s and will build a 3rd motion sensor with one of these. In the meantime I also changed some things in the code to reduce the JeeNode power usage in power down mode even more: it went down from 20 µA to 6.5 µA. Calculations show a theoretical battery life of 200 weeks… well, i think the internal discharge will have screwed up the battery before that…

BTW, the 2 motion sensors that are currently being used, are still running fine on their first set of batteries.

Volcano

Did I miss my daily tinkering with JeeNodes, XBees and all other things i play with during my leisure time? Not really; it’s actually good to know this “addiction” is still curable, cause i had no withdrawal symptoms. On the other hand, I never forgot to take my iPod Touch with me for the daily email check when we went to the restaurant for breakfast… hmm, well how about that one

But nothing is what it seems, cause after 2 days at home, I’m itchy to start all those new things I thought about while I was away. Too much!

Nothing is what it seems

And the list was already much too long before I left; OMG, where do I start??? Choices…

Too heavy?

Cameras, MP3 players, a laptop, clock radio, iPod, portable HDD, card reader and all the things you need to keep those things operational for 2 weeks, like cables, adapters and battery chargers. And there are still some things missing from this picture, like 2 game consoles (and their adapters) for our kids, the adapter for my cell phone, a few computer magazines, a power distribution box (cause we’re always short on wall sockets)… yes, that will be enough to fill that 3rd suitcase, which we call the ‘gadget suitcase’. It’s getting heavier every year…

But why not try it some time? It has been on the to-do list for some time, but never made it to the top-5. But when there was another question recently from someone for whom i gladly spend lots of time without any personal gain or interest, i decided to try some things to see if a first small step could be made. I put 1 of my spare XBee modules into a XBee adapter, loaded the firmware version 2864 (XB24-ZB End Device AT), set the preconfigured PAN id to 0 (which means the XBee will join any PAN it can find) and uploaded the new configuration.

Now there’s this small green LED on the adapter labeled as ‘ASC’, which tells you the associated state of the XBee. When it starts blinking rapidly, you know you’re going in the right direction … reading back the Operating PAN ID from the XBee showed me a value like D6F0000134567. Hey, where have i seen that value before? It looks like a Ember MAC address.. YES, it’s the MAC address of my Circle+ ! How odd…

OK, i know. This is just a very small step; i know the PAN ID of the Plugwise network now; duh. Next thing to figure out is the encryption key; it’s time to join forces on this project that is in the top-5 now and is there to stay!

Plugwise still sucks in some perspectives, but this is nice. And i have no idea if this will ever come to something useful. But that doesn’t matter, just as long as I’m having fun with what I’m doing

I still have 10 DS1820 1-Wire sensors somewhere from the days when i started with Domotica, but i never used them; maybe now i finally found a purpose for them? Let’s connect a few to an Arduino and see if  i can get a temperature reading:

Arduino with 3 x DS1820

And of course, there’s a library to use 1-Wire devices with an Arduino.. so before i knew it, i was polling the temperature of 3 DS1820s

Addr:10 6C 5 CA 0 8 0 C3  Temp=25.50 grC
Addr:10 33 EC 3 1 8 0 E1  Temp=25.50 grC
Addr:10 FB 90 C9 0 8 0 1A  Temp=25.50 grC

Addr:10 6C 5 CA 0 8 0 C3  Temp=25.50 grC
Addr:10 33 EC 3 1 8 0 E1  Temp=25.50 grC
Addr:10 FB 90 C9 0 8 0 1A  Temp=25.50 grC

Addr:10 6C 5 CA 0 8 0 C3  Temp=25.50 grC
Addr:10 33 EC 3 1 8 0 E1  Temp=25.50 grC
Addr:10 FB 90 C9 0 8 0 1A  Temp=25.50 grC

Add an additional LDR and I’m done; ready to replace a large part of all my sensors: all remaining MS13s and most of my Oregon Scientific Temperature & Humidity sensors with my own

• The JeeNodes active time during a period of 24h is 102.4 seconds, with a current of 6.5 mA;
• Power down current is 20 µA;
• The XBee sends an average of 120 packets per hour, requiring the XBee to be on for a duration of 34 ms for each packet, using 40 mA current (from the datasheet);
• XBee power down current is 1 µA (datasheet);
• The PIR uses 170 µA (datasheet) while in standby mode and 270 µA (datasheet) during motion detection; motion detection duration is estimated at 400 seconds.

With these numbers it should be possible to calculate the average power consumption of each component:

• JeeNode: 27,68 µA;
• XBee: 2,88 µA;
• PIR: 170,46 µA.

This adds up to a total of 201,02 µA. That’s the average current the motion sensor is using, based on a period of 24 hours.  With 2000 mAh batteries this results in 9950 hours = 414 days = 59 weeks… cool! That will do, for now, lol

However… how about the battery self-discharge?? How much will this influence the time this motion sensor will last on 1 set of batteries? I really don’t know; so, still, time will tell how well this sensor performs in terms of long lasting batteries.

Fortunately, I still have enough options to reduce power usage even more, like

1. Using the energy saving version of the PIR;
2. Disabling stuff on the ATmega like brown out detection (how do i change fuses? As i mentioned before, where will this end? );
3. Running the ATmega on a lower frequency.

And now that i have it all in a spreadsheet, i can manually adjust some values and see how it effects battery life. The smartest thing would be to go for the 1st option, cause that would reduce the standby current of the PIR down to 46 µA instead of 170… meaning 3 years !!

I’m going to order some extra PIR’s now…

The question is, do i really need it? Or shall i proceed with a door/window sensor? Or go on building these motion sensors until i have replaced all the MS13 sensors i removed from my house some time ago and the few that are still being used? Or first finish the LED strips… tough choices!

I upgraded an existing v1 sensor to a v2 and built a new one. The v2 sensor specs are very different from the v1 but much more promising, yet all i needed to do to was soldering the digital output of the PIR to another JeeNode port (namely ATmega INT1) and use a different digital port for serial I/O with the XBee. Oh, and upload a new sketch of course. Now i have 2 identical v2 sensors:

v1 upgraded to v2

Looking back at how this motion sensor evolved i am wondering, why didn’t i think of interrupts in the first place… not very smart actually..

Or maybe i did think about interrupts but unconsciously thought it would be to hard for me to handle already, cause that’s what you read all the time: interrupts are a tough subject! Maybe it is, but i didn’t notice that yet!

So now I’ve got 2 motion sensors with the following features:

• powered by 3 * 1.2V, 2000 mAh rechargeable batteries;
• PIR with digital output, 100µA standby power usage and 5m detection range;
• a JeeNode that’s effectively running only a total of about 180 seconds per day (0.2 %), even with 350-400 motion reports and lots of heartbeats. The rest of the time the JeeNode is in power down mode;
• it’s ZigBee based which is better than 433 MHz in my opinion, especially when you’ve got a lot of sensors;
• relatively small sensor housing compared to commercial (mostly big and ugly) products;
• completely DIY so everything is how i want it to be;
• interrupt-based, the best you can get I’d say;
• need i go on? 

I’m gonna monitor this sensor very closely in the coming months and learn from it. Here you see one of the sensors being used in the kitchen:

Motion v2 in the kitchen

The sketch that’s currently running on these sensors can be found here.

Finished? Almost; some loose ends in the sketch. Maybe it can be made even smaller/faster/less energy consuming. But I’ll look into that when the 3rd sensor is built.

Here it is, Motion Sensor v2. Not much different from v1 really, the only thing that has changed is that the PIR output has moved to an interrupt pin. And the sketch looks somewhat different here and there. Later this week i’ll build my 2nd motion sensor and start using it right away; i’m very curious about the results! I’ll also change my 1st motion sensor that’s already in use, to an interrupt driven model. Don’t want to wait for what will happen with those batteries…

The JeeNode is completely powered down most of the time. It only gets woken up by the Watchdog timer every 8 seconds or when motion is detected. But even when motion is detected, it’s powered down most of the time, cause a ‘blip’ sent to my Domotica System every 4 seconds during continuous motion is more than enough.

When the motion interrupt is triggered, the ‘blip’ is sent to my system, followed by a power down for 4 seconds without interrupt trigger set. When those 4 seconds have passed (wake up is done by the watchdog timer) a power down is done with interrupt trigger and the whole loop starts all over again. Capice? It doesn’t get much easier than this

And of course there’s a heartbeat sent every 64 (8 times 8 ) seconds.