Any suggestions on a no-brainer and safe way to get external input recognis ed by a PC please? Apart from a voice command approach. Or a solenoid to ta p a key. For example a cheap commercial or easily built switch or momentary button with a USB plug at its end. That sort of thing.
with windows you can use a USB to Serial (RS232) adapter... The OS see's most of these on the market as standard so there should be a driver already on board..
Windows provides a ESCAPE function that allows you to Read and Write the INPUTS and output pins of the port.
Also Windows provides a WAIT function so that your code can responed to it via a trigger, but this should be done in a secondary Thread or you could simply scan the port at timely intervals.
you get more input than you do output though..
CD :Carrier detect; RD :Ring Detect; DSR :Data Set Ready; CTS :Clear to Send;
Whereas for output you don't get as much.
DTR :Data Terminal ready. CTR :Clear to Receive; And some devices will support the BREAK single which places the TX pin to low or high state depending on how you do it.
Depending on how good your adapter is, you can most likely drive them up to around 10Volts without issues but the output will most likely be like around 5 volts, some will actually do 10-12 volts depending on how good they are.
USB joystick interface. (or just pull apart a $3 USB gamepad) several digital inputs with pull-ups
will need software support to generate keyboard events
USB serial port: 5 inputs 3 outputs. inputs TTL compatible, +/- 24V tolerant ouputs approx +/- 10V 1200 ohms impedance will need software support to generate keyboard events USB keyboard - cut the sucker open and use an optocoupler or relay to mimic the keyboard switches - or you can buy just the electronic part from sparkfun etc.
AVRUSB or other usb-device capable microcontroller.
When I tried casting out nines I made a hash of it.
ised by a PC please? Apart from a voice command approach. Or a solenoid to tap a key. For example a cheap commercial or easily built switch or momenta ry button with a USB plug at its end. That sort of thing.
There's dozens of gizmos for slideshows, with a few remote buttons, that ca n handle the task. All USB implemetations recognize some generic device types, the remotes are usually keyboards (with only a few buttons). The Macintosh media remote (bluetoot h, I think) can be emulated by a cellphone app, so you might have all the needed parts alr eady, just a small matter of programing.