john1993:
most efficient solution is running an m328 directly off 1s lipo.
Except if you have bunch of 5V powered peripherials as in that case...
Wasferd:
Would I be able to use the SparkFun LiPo Fuel Gauge and program the Arduino to enter sleep mode at 3V?
If I disable the power LED and since I am bypassing the Linear regulator the current consumption will be 0.0058 mA is that good enough?
What about other parts? Could you put them into sleep mode as well?
If you need to protect battery, you need to really shut down everything, to single microamps.
About battery protection - check step-up converters as some of them already have such protection.
majek:
Except if you have bunch of 5V powered peripherials as in that case...
after a brief glance i suspect in addition to the avr that "myoware", rf, and flash card all capable of 3v operation. possibly all have sleep mode too and if not a penny pfet would take care of that.
also note that most switching converters generate orders of magnitude more noise which might wreak havoc with the emg and rf. of course efficiency and economy are not always the chosen path. many find the whole concept of simplicity abhorrent, specially on the internet.
"The cheapest, fastest, and most reliable components of a system are those that aren't there." -Graham Bell
majek:
Except if you have bunch of 5V powered peripherials as in that case...
What about other parts? Could you put them into sleep mode as well?
If you need to protect battery, you need to really shut down everything, to single microamps.
About battery protection - check step-up converters as some of them already have such protection.
Wouldnt all the peripherals cease working if the Arduino is put in sleep mode?
Wasferd:
Wouldnt all the peripherals cease working if the Arduino is put in sleep mode?
They stop working, but they don't stop draw current until you put them into sleep or cut them power if sleep mode is unavailable.
You need to study datasheet of all your peripherials if you want to go this way.
They are going to be integrated into a 3D-printed wristband. Hence the battery needs to be small and light. There is no minimal operational time requirement. However the longer the better.
I intend to power through the VCC pin bypassing the Arduino on-board linear voltage regulator.
I am thinking of using this Lithium Ion Polymer Battery - 3.7v 500mAh with a 5V Step-Up/Step-Down Voltage Regulator. The battery has its own PCB that will cut-out the battery when completely dead at 3V.
So Ill have the LiPo battery connected to an external switching voltage regulator connected to the VCC pin.
How does that sound? am I missing anything? I will possibly also use the SparkFun LiPo Fuel Gauge to monitor the battery voltage as an extra measure of safety.