Hello,
I am working on a temperature monitoring system. The sensor node streams data to the server node every minute and records it in the memory card as well.The components are of sensor node :
Arduino pro mini 3.3v
RFM69HCW RADIO MODULE
DS3231 Timeclock
Memory Card Module.
I am supplying power with 3*1.5V batteries but they are consumed very fast by the circuit. I want the sensor node to work for at least 3 months. Any solution.
Get a multi-meter. Measure the current current consumption.
Those modules connected to ground and V+ are continuously drawing power....
Show a schematic.
Those LED's all light up in a closed box do what when they are illuminated? Draw power. Now what good is a LED doing you in a closed box? You can unsolder them.
When you figure out you need to put the MCU in sleep mode, you may consider powering down the other modules whiles the MCU sleeps. Be careful that your power down/power up device does not draw more current then the powered devices consume.
Look into using Li batteries.
Better yet, look into using LiFePo4 batteries. They act just like lead acid batteries but more better. A 12V 6Ah LiFePo4 would be a good fit, just a guess, and can be recharged from your car battery charger.
Search for Nick Gammon's page on low power modes for Arduino.
@IdahoWalker
It's taking 10/50mA continuously alternating at these two values. The LEDs show that the modules are powered up.
kazmi12:
@IdahoWalker
It's taking 10/50mA continuously alternating at these two values. The LEDs show that the modules are powered up.
Do the LED's consume battery power?
When the case is closed can you see the LED's?
Yes, when the case is closed I can see the LEDs its a see-through case I will be using. LEDs are embedded in modules they will be consuming some power
Ok, you need to LED's on more then you need 3 months of operation on battery power. I suggest you get a bigger battery.
Any suggestions for the battery that can supply 50mA for at least 3 months...
Look at USB battery banks. Some of them purportedly have sufficient capacity.
Well 3 months is how many hours; 90 days at 24 hours per day is 2160 hours of run time.
With the number of hours you need be running and assuming the circuit is using 50mAh per hour and the battery is discharged down to 10% of its rated storage, you'll want a, at least, 120Ah battery Battery Life Calculator; which is gonna cost you several pretty pennies.
What you might consider, it's what I do, is get a 6 to 12 Ah LifePo4 (I'm using a 8Ah LifePo4), a PWM Controller, and a 10W 12V(loaded) solar cell; I'm using 50Watts solar cell with running motors. The project runs off the battery, the PWM controller tries to keep the battery charged and the solar cell provides power for charging.
Oh, and you'll get more than 3 months of operation with a solar cell.
The cheaper way of doing the thing is to use a TP4056 as your battery charger and a 2200mAh to 3300mAh Lipo as a supply source. A TP4056 can take up to 8V, I think. If you supply a bit over 5V to the TP4056, you can use a LDR (low drop out) regulator. The LDO will act as a 'safety' switch of sorts. You'll not want to completly drain the LiPo, thus the LDO.
The issue is that LiPo's do not have a good way of recharging by way of solar power, so from time to time you will have to replace the LiPo's. Also, this scheme does not work in freezing weather. LiPo's freeze at 0C or 32F. Once a LiPo has frozen, throw it away.
Considder one battery pack for your agressivly low power controller and sensors.
Then 2 more to allow for the drain caused by the LEDs.
those LEDs are useless, and you really need to cut them out
you can however connect one LED say on pin# x on your arduino, which blinks at a varying different rates
-
to show program runs fine ( not locked up)
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rate1 to show that your SD card module is intact
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rate2 to show your RTC module is intact, etc , etc
each item uses power.
the micro sleeps at microamps
the SD card in sleep mode uses ? depending on library, mA or microamps
the RF uses somewhere between 20mA and 150mA when active.
150mA for 1 second, 60 times an hour, one 16850 battery would last for about 33 days. for transmit mode.
plus sleep mode
As for the LED's Oregon Embedded - Battery Life Calculator
each LED at 5mA, will burn one 16850 battery in about 17 days. so, just for the 3 LED's for 3 months, you need to have 18 of the 16850 batteries. Double that if they run at 10mA.
What is needed is to calculate each item for power consumption, then either figure out what is absolutely required or what is not required.
Change the transmit to once every 5 minutes and you might get away with 1 battery for that device.
and, 18 more ( 36?) to power the LED's
use and flash only 1 LED, once a second for about 50mS, and you only need 1 battery for the LED