I have an Arduino Uno, Xbee shield and Xbee. I am trying to test this in cold weather, like placing the the setup outside (-20 degrees) and having reception end inside. It seems that it works at the beginning, but the sending gets more unreliable in few minutes, until receiver doesn't receive anything anyone. At least transmitter led is still operating. Back inside the system works again.
I am wondering what is the problem here. If I understood correctly at least Xbee should stand coldness till -40, at least in theory.
Yes, I am using a 9V battery. I will still run some tests, but at least the Xbee led is blinking for sign of transmission. Yes, I figured that Arduino is probably the one causing problems.
While the Arduino requires 5V, the XBee only requires 3.3V. I'd investigate the battery -- you could try wrapping it up in a sock with one of those heater packs to keep it warm as a quick test.
Yes, I am using a 9V battery. I will still run some tests, but at least the Xbee led is blinking for sign of transmission. Yes, I figured that Arduino is probably the one causing problems.
I'd have thought that the battery is probably the one causing the issues.
Can you rig a temp sensor up so you know how cold it's getting?
Ok, so I ran another test by leaving battery inside with a long cord. Device is transmitting, but the range is barely 5 meters. Although there are two glass doors between the nodes. This is the XBee that I am using.
rocketgeek:
Are the windows insulated glass? I understand that often has a thin metalized film in it that could conceivably interfere with transmission.
Pilkington K glass does (triple glazed, argon filled, double pilkington K glass here)
I don't think that would cause any issues - not over time anyway.
63 mW output (but the chip antenna designation kinda gives that away already, huh?)
250kbps communication speed
3.3V @ 50mA power consumption
1.6kM (1 mile) range (line-of sight, which is pretty darn good!)
6 10-bit ADC input pins
8 digital I/O pins
128-bit encryption
Uses standard AT or API command sets
Industrial temperature rating (-40° C to 85° C), so feel free to use it in your hot-tub in Iceland.
FCC certified for USA, Canada, Australia, & Europe. No worries about men in antenna-ladden vans driving up to your house with a "you've been naughty" look on their faces.
So, I made another a bit more clarifying test. First I was keeping the battery inside and opened another of the glass doors. Works well till ~10 meters. When I take battery outside(not covered in any way) the reception starts showing weakening performance gradually (today there is only -5 outside).
Yes, I was thinking also about the pro models of XBee. Actually this project of mine is a thesis work for school, so I basically have to demonstrate the functionality. I will probably mention the need of better chip and battery environment optimization in the documentation part of the work.
Chiming in about battery performance in cold weather; I do a fair bit of photography and one full charge can usually last me more than a thousand frames in regular temperatues (say, 20 degrees C). Last year though, I was shooting in -3.5C, battery life was shortened to about ~500 shots. This is a li-ion battery encased in a plastic casing, that's enclosed in a magnesium alloy shell covered in rubber. YMMV.
and battery environment optimization in the documentation part of the work.
Well - just a better battery.
9V batteries can't supply a lot of current at the best of times, in very cold weather this will be much more of an issue - and as TrinsicWS says, battery capacity decreases dramatically at low temperatures too.