what i want is a single sound to play when the pir seonsor is tripped and only play once and the shut down until the sensor is tripped again.
The issue is that the PIR sensor is not a single trip, it's going to trip and continue to trip as it senses motion... That is why I'm asking about a delay, if you just want each track to complete and then if there is still movement play again that isn't a problem... But, in this case a single kid might trip it multiple times if he/she doesn't move out of the PIR detection area...
amplification is limated to the speakers as it is in the middle of lots of houses so we dont want it to loud
Voice level talking? Shouting? Give me an idea, also your speaker specifications...
we dont have space constraints as i build the box as big as is needed and can place it anywhere.
That really helps lower cost...
duration of the sounds wil only be like 1 or 2 seconds each
This again potentially lowers cost, dependent on the playback device...
my bugget is less the £100 if possible but not really looked how much parts are.
That is really tight for a custom 4 sound playback system, not saying it can't be done but you might not get exactly what you want if trying to hold that budget, I'm guessing you will get something really sub-par of what you expect... Basically you are only budgeting £20 a playback unit, with the remaining £20 for a new power supply and misc... That really isn't going to get you far on a custom solution, I doubt it will even cover the cost of components and PC board manufacturing... You would really need to kit bash some using low cost over the counter parts (if you can find them) to hold that price...
Do you have any experience and/or are you going at building this yourself or do you want to purchase something that is pretty much ready to go with a few plugs?
I would love to help you out, but I'm doubtful that I can within that budget making 4 sound playback devices that cheap isn't easy without really knowing what you are doing, and using over the counter cheap Mp3 players bashed to work still needs a lot of tinkering and might not really be reliable at the end of the day and from what I guess would still be pushing your £100 budget before it's done...
On the flip side, I would love to help make/deliver a custom circuit for you as it would be a fun build, but even with the favorable £ to $ conversion I just can't see it happening...
And last but not least if this system was at one time working, you might be able to get it working again... Might not be what you want but it might buy you enough time to budget more money for a better replacement down the line... The first thing you would need to do if this is your course is to take them DSU200 and give them a bath in some soapy water and let them dry, so we can maybe get an idea what they are...