The resulting solution must run on batteries (coin type ideally) and I wanted to get a sense of the operating time between battery changes. The spreadsheet utilized the cells in red as variables. Assuming a wake up during of 30ms and sending a sample every 100 seconds, I can run for an acceptable amount of time. The problem occurs when I include a 78L33 level converter, 555 timer, and a sample sensor like the LM35. I will need to look into this as this might be a show stopper on the battery only constraint.
I have set up my test circuits to using a 555 timer and create a 99% duty cycle for a duration of 100 seconds or so. It does wake the xbee up and transmits to the host software. Now I need to re-evaluate things from a power consumption side.
I will measure the actual current when I build the prototype.
|Level Converter (5 to 3.3 V)|
|Aprrox Wakeups per 24 hr||864||count|
|Approx wakeup duration per 24 hr||25920||ms|
|XBee Current per wakeup||95||mA|
|Xbee mA per 24 hours consumed during wakeup||0.684||mA|
|Xbee mA per 24 hours consumed during sleep||0.009997||mA|
|mA per 24 consumed 555||2.4||mA|
|mA per 24 consumed LM35||1.44||mA|
|mA per 24 consumed 78L33||132||mA|
|# of days for one battery w/o 78L33||44.0||days|
|# of days for one battery 78L33||1.0||days|
|# of days for one battery w/o 78L33,555, LM35||288.0||days|