i would to do node with moteino and few sensors. i buy pressure sensor - bmp 180 - to get temperature and pressure and photoresistor. The connection scheme is simple. Only one difference i connect power from moteino digital pin - i set pin HIGHT before get results from bmp180. The same way I do with photoresistor. I do so because I wanted to save power - i try to turn power on for sensors only at the time of measurement. All work good but it is good idea?
Addition the photoresistor is used with 10k resistor as voltage divider.
i doing measurement every five minutes.
I supply power to moteino with 9v battery.
The main problem is the battery. it is empty after two days.... I thought this would work at least a few months.
this is my sketch: http://pastebin.com/PiJMvwdp
Can anyone tell me what can be wrong? or maybe is it correct?
Thanks!
From a brief look, it appears you're sleeping the radio and the MCU which is good and you indicated you power your sensors from digital pins.
There are numerous threads in the forum on this topic. You have to make absolutely sure nothing is waking up the Moteino from sleep.
Also you need to power down EVERYTHING that might draw power. If your sensors have pullups on data pins it's possible they drain the battery.
I see a delay(1000); and some delay(status) calls. I assume those are for the DHT taking a very long time to read. Those are red flags though. There was a recent sticky topic about reading such sensors without keeping the MCU awake.
Also a lot of other things can be overlooked but hard to guess without the hardware in my hand.
Just powering from 9V battery and expecting to last for months is not a very good test. You will need to make some power draw tests with a true RMS multimeter and see when there is drain on the battery and identify the source that way. Otherwise you have no way of knowing what your circuit is doing and can't have any expectations. You can achieve very low power with Moteinos.
i turn power down for sensors by cut power by set moteino pin to LOW.
Pressure sensor use i2c interface. Can i2c drain power? DHT22 now is not connected - in sketch is commented method to read.
I have to use some delay() because sensor need it. Without delay sensor return wrong value. BMP180 description says that is low-power digital barometer but it probably is not true.
Maybe there's someone who built weather station and can describe what the sensors used and how, and how long the battery lasts.
I am very beginner, and I see that it's probably not that simple, unfortunately.
Thanks
You will need a good true RMS multimiter at the very least to start understanding what your circuit is doing in terms of power draw.
You can search the forum, there are other posts regarding the DHT sensors, including code and details. I haven't used that sensor simply because of the limitations and the long delays it requires.
I will think about buying a true rms multimeter, but I see that it is quite expensive. i will use DHT too, but this sensor does not measure the pressure. Maybe you know pressure sensor that will be working with no problem? :)
anyway, thanks for help :)
Doing electronics without a good multimeter is like a mechanic with no tools or a doctor without a stethoscope ;)
I don't have a recommendation for those types of sensors off the top of my head, sorry.
Would you be able to suggest a quality True RMS multimeter in the $100 to $200 range?
Not really for that price range. But there's the Fluke 115: http://www.amazon.com/Fluke-115-Compact-True-RMS-Multimeter/dp/B000OCFFMW/ref=sr_1_8?ie=UTF8&qid=1412859093&sr=8-8&keywords=fluke+87
And I use the Fluke 87V: http://www.amazon.com/Fluke-FLUKE-87-V-Digital-Multimeter/dp/B0002YFD1K/ref=sr_1_1?ie=UTF8&qid=1412859093&sr=8-1&keywords=fluke+87
This is also a good one: http://www.amazon.com/Agilent-U1272A-Handheld-Counts-True/dp/B004URG9EU/ref=sr_1_9?ie=UTF8&qid=1412859172&sr=8-9&keywords=agilent+multimeter
Remember, you buy these once, for life.