Hardware

I saw an example sketch on how to control the module the linked page. You can use the LED dimmer example on mysesnors to set/receive dim-level from controller. Yes, you could use your regular wall-switched as input to an arduino (disconnected from AC), but you would probably not be able to fit the electronics behind the switch. Working with AC is dangerous. You need to know what you are doing!

@marceltrapman said: @royaraya16 said: In my opinion there's no need to use the crystal, you can use de 8MHz internal clock. I have not yet read the article by why is it then that all Arduino boards (that I know of) make use of a crystal? Becauses it is easier, gives a more reliable oscilator (over a wide temperature, and voltage range), and the first arduino was designed with 16Mhz crystal (if I remember correctly). the maximum internal rc osc. is 8Mhz / Thomas

RFduino uses BLE (Bluetooth Low Energy). While this is also 2.4GHz it's not compatible with nRF24L01 in terms of protocol.

@Rek said: Does anyone have the spec sheet for the Chinese step up regulator? I bought a few of these to test http://www.pololu.com/product/2561 My guess is that it is or is similar to the 2108A in SOT89-3 described here: http://fullmany.com/Upload/file/ME2108%20series-E8_0.pdf

@Zeph Thanks that is what I thought but I wanted to make sure :)

Here's another project which passes a fire detection to a Home Automation System, much as I'm suggesting: http://harizanov.com/2014/07/diy-internet-of-things-fire-alarm/ The idea I was exploring is including our other sensors in the same housing if possible, and also making the piezo speaker a controllable actuator within our network. I don't have a 120V interconnected system (sound nice tho), but that's a good option for detection for those who do. Another option for interfacing a Home Automation system with multiple networked alarms - like the battery powered First Alert OneLink system - would be decoding the 433 MHz signals passed between these alarms. That of course does not take advantage of "hiding" a MySensors multi-sensor node inside the housing of a smoke alarm, tho. I kind of like the option of not needing to explain what these new boxes are in every room - if the sensor nodes look like smoke alarms, nobody will even notice them. And if that's done by making them hidden additions inside real and still-functioning real smoke alarms, even better!

@meanpenugin Thanks. Definitely stranded, but even the options that's I've put my hands on aren't as flexible as a standard USB cable. I think the difference is in the jacket material. I've order, what I hope will work from MCM, so I shall see. I would have never guessed that finding nice flexible 4 conductor ~22 gauge wire would be such an issue. ;-)

I have some FirstAlert OneLink smoke detectors; they network together at 433 MHz. Each gets a room type (selected from a fixed menu of a dozen: Kitchen, Utility Room, Master Bedroom...); the audio for speaking the names is in the ROM. If one goes off, they all go off and announce loudly - "Alert Alert Evacuate Immediately - Smoke in the Utility Room" (along with beeps). Runs on 2xAA. It's a good idea but... Something more customizable would be good. Last week it woke us at 3am to let us know that the battery in one of the remote rooms needed replacing - same loud alarm and voice as a fire being announced throughout the house and waking everybody up. Also the selection of room names doesn't always fit - we have to remember that we called the office a "utillity room" during setup because they don't have all the room names to match our house. (I did at least write the names on the outside of the units so I can sort it out by getting close to each unit in turn, without going into config mode to have it repeat its own name). It would be nice if the "outdoor voice" was reserved for real alarms, and battery warnings arrived by email, or in a softer voice and during the daytime only, or whatever. So a customizable and interfaceable [not real words but they should be] version of this system would be good. I do not know how hard it would be to hack a conventional smoke alarm. For safety I would probably want to keep the direct alarm connected (no un-alarmed fires due to software bugs). But one could perhaps add the ability to also trigger the buzzer in firmware as suggested above (eg: for intrusion alarms, or to relay a smoke alarm as the OneLink does), and to pass on a locally detected alarm to the system (for relaying or for announcing in other ways). Duplicating the OneLink functionality would also require a loud but tiny speaker in each unit, with locally stored voice announcements.

Opps, I meant to say @Bandra 's board is a great small footprint board, If you're looking for small form factor, I highly recommend his.

I haven't been running that one at 3.3v, but there are a number of designs with 16MHz ATMegas at 3.3v that seem to do fine. It's outside of spec, but I've read that even Atmel engineers have indicated to some designers that the specs are very conservative, and some vendors report having shipped thousands of units (of 16MHz@3.3v) without problems with that. Perhaps it would sometimes be a problem at extremes of their temperature range? By the way, there are also Arduino Pro Mini's on eBay which can be converted between 3.3V and 5V (at 16 MHz), albeit usually with a solder bridge rather than a switch. Search Arduino Pro Mini adjustable.

For refill prediction you might wanna add a distance sensor in the tank (if possible) measuring the oil level. There is a variant that can handle rough conditions in the "shop".

Hey all, I"ve got a question about wire wrap, I bought some from a local electronics store but it seems that there isn't traditional insulation on the wire, it seems more like a paint. Is this typical? Or did I buy the wrong thing.... It's 26AWG

Here is in effect the same sketch for 1.4. Im using @Yveaux 's vcc library this time.vcc library https://codebender.cc/sketch:54782 Im no longer using the changed boards.txt. - it doesnt seem to do anything ( other than stuffing the serial output)

@soward I use some sort of no-name 10 uH 12mm (I know, stupidly big) shielded inductor from AliExpress. Looks a lot like these, fairly bulky and heavy: http://m2.uxcell.com/photo_new/20140506/c/ux_a14050600ux0992_ux_c.jpg Haven't done more than go over it with the continuity tester to see that it didn't have some sort of rudimentary inside damage. I also tested the capacitors, they were close enough to 10 uF but I did some surprising minor variation that can't be blamed on the DMM. Random Ebay caps are probably not a good idea if you need spot on values. But they did seem to work.

@Yveaux said: there should be some OKI tiles somewhere, or maybe some blobs of resin somewhere on the back? I dug a bit further and under some green tape I found something: [image: upload-fcac12ad-87ad-47c6-9035-d3635d2bbbf0.jpg] [image: upload-96483404-3883-4553-abd4-3b3818c366ce.jpg] So I guess these might be the LCD controllers then. Anyway, if someone feels like sinking their teeths in one of these let me know.

@hek : Thanks so much... no idea why I didn't see that earlier. I think you can close this post.

@ivan.todorovich Hi! See this examples how to power it from 220V without tranformer. http://www.designercircuits.com/DesignNote1a.pdf

Thanks, Didn't spot those, mainly because they looked like 5v > 3.3v in the heading. I'll maybe buy some of those plus find some of the 5V ones i see in the manufacturers spec sheet.

Minimum? Well, you need the 3 fixed SPI pins and 2 more (CSN and CE) to run the radio (at least in the normal manner). And whatever pins you need for sensors and actuators.