If I go with heater, what have you used for a heater?
QuoteIf I go with heater, what have you used for a heater? Just use power resistors sized for the amount of heat required. Turn them on and off via a switching transistor wire to the arduino with a temp sensor. Or pwm it with a PID control function and have continuous heater control. Resistors are 100% efficient at converting electrical power to heat output.
I also considered good old fashioned light bulbs, that generate heat. They say to heat a doghouse in Calgary with a incadescent 100W light bulb, to keep the dog warm, not sure how low of a temperature that would be effective.
I know the pink stuff very well, used many sheets on my train layout for scenery the new purple has better R factor, as for rain, Calgary is almost a desert re: rainfall, and the snow is dry ;^)
-40C = -40F, that's pretty cold!
The ATMega328P is rated over a pretty broad range. How cold are you likely to see?Temperature Range: -40°C to 85°C-40C = -40F, that's pretty cold!