I'm a bit of a beginner to say the least, but have recently started using Model A boards and Crontab to play audio files to a timed schedule. The project is being run off 12v, and away from the internet, so I'm using the Afterthought Software RasClock to provide the time:
http://afterthoughtsoftware.com/products/rasclock
As it spends most of it's time idle, the Pi will last for a few days on a 7Ah 12v battery without any problems. The only issue is that the amplifier I'm using will only last about 8.5hrs on a battery with the same capacity. So, my idea to get the whole setup to last for a few days was to use the GPIO and a relay to switch on the amplifier before playing the audio, and then to switch it off again until the next time it needs to play a sound (it only needs to play for a few seconds 8x per day). I'd found a good 'how-to' here:
http://www.susa.net/wordpress/2012/06/r ... sing-gpio/
...and was all set to go ahead when I realised that the RasClock is sat on both 5v pins, and one is needed by the relay circuit.
So, I was wondering if it would be possible to share the 5v pin between the relay circuit and the RasClock. There does appear to be a pass-through socket for a jump-pin on the board marked '+5v' (see pic below) but I can't find anything out about it on the Afterthought website.
Any pointers would be great.
