Hi! Well, in a perfect world it is possible to do what you suggest from user space, but in practice you will probably need to write a driver for it. The reason is the fact that linux is multitasking and non-realtime. Every time linux switches execution to another process, your application will stop generating tones for a few mS. So I suggest that you build a small oscillator, for example with the 555 IC. Or build two, one for each tone, and connect the reset inputs of the 555s to the outputs of the foxboard. Then use a simple diode based OR function from to drive the transistor. Or use an AVR =).
Regards /Tobias nickcol skrev: > > Hi > > Ive ordered a fox board and am looking at creating a clockin unit for > work. Think I would use a serial card reader and 4 line lcd. Im quite > happy on wireing this up and using linux to program it > > My only problem is that I need to generate 2 tones, One for card > swiped ok (high pitch) and one deep tone for if the swipe failed. > > Is it possible to use one of the outputs with a buffer or transistor > to drive a small speaker or pc buzzer. I would just turn it on/off at > a set speed. ? > > Thanks in advance for any pointers. > > Nick > >
