Hello to everyone !
I`m trying to build a little system that would every hour read an audio message, working on battery.
The raspberry pie appeared pretty relevant as i could put the audio files on an sd card that would be read on a speaker pluged on the jack and powered by the gpio
The only problem ( from my noob point of view) is still the battery problem. With a consumption of 800 mA( counting large with a model A and a speacker that doesn t need to be very loud, just to be clearly heard in the room) during 3 minutes ( turning on, reading the mp3 , turning off) it would last 4 days on by portable battery ( 5V -1A-3000mAh) which is far from great but reasonnable.
In this position I need something that would turn on every hour for 3 minutes and then turn off the current.
The sleepy pie appeared absolutely ideal. If it wasn t three times the price of the Rpi.
the vm 188 seems ok too for this job... but the price is still quite high and it would require a 12V power and a tension reductor to then power the rasberry pie https://www.quasarelectronics.co.uk/Ite ... mer-module
And then I discovered little thing like those http://www.ebay.com/itm/DC-3V-24V-Cycle ... 2a4de72891
Which : ( but my poor english doesn t allow me to be sure)
-To turn on every 58 minutes for 2 minutes and then shut down
-Consume 0.5mA during its idle time
And thus truly allow me to plug that into my usb battery and my raspberry pie.
I tried to explicit at the maximum my requirements for you to understand what is going on, i know both the sleepy pie and the vm188 have been used for such jobs and i wonder why this wouldn t do the job.
Thank you Very much, I know this is not directly Rpi related but I would be happy to learn if this seens reasonable and learn about all kind of thing on subjects on which I would love to know more ( electronic and.. so !)